Class Notes Material

AMERICAN PETROLEUM INSTITUTE

INSIDE EXPLORATION TECHNOLOGIES

API 510 PRESSURE VESSEL INSPECTOR

Paul Philips PAUL PHILIPS.J

Digitally signed by Paul Philips DN: cn=Paul Philips, c=QA, o=Jacob Inspection Services, ou=Oil & Gas Industry, email=paulphilips. [email protected] Reason: I attest to the accuracy and integrity of this document Date: 2011.12.07 20:35:51 +04'00'

API 510 CERTIFICATION COURSE FOR

AUTHORISED PRESSURE VESSEL INSPECTOR

PREPARATORY MATERIAL

CONDUCTED BY

Inside Exploration Technologies Chennai, Tamilnadu-India

PAUL PHILIPS.J

API 510- PRESSURE VESSEL INSPECTOR COURSE

VOLUME-1 CONTENTS PROGRAM SCHEDULE PART I - CERTIFICATION INFORMATION FROM API. PART II - GUIDELINES FOR CLEARING API 510 EXAMINATION PART III - CODE WISE PUNCH POINTS PART IV- CASE STUDIES, PART V -

WPS/PQR ROAD-MAP AND REVIEW

PART VI - ADDITIONAL INFORMATION PART VII - DAILY EXAM & POINTS TO RECALL

PART VIII - QUESTION BANK: QUESTIONS ON API 510 CODES PART IX - QUESTION BANK: QUESTIONS ON ASME CODES PART X - QUESTION BANK: QUESTIONS ON RECOMMENDED PRACTICES

PAUL PHILIPS.J

API 510- INSERVICE PRESSURE VESSEL INSPECTOR PREPARATORY COURSE

PART I

CERTIFICATION INFORMATION FROM API

PAUL PHILIPS.J

API 510 CERTIFICATION COURSE FOR

AUTHORISED PRESSURE VESSEL INSPECTOR

COURSE NOTES

VOLUME - I

CONDUCTED BY

Inside Exploration Technologies (P) Ltd Chennai, India. 12 – 18 September 2011.

PAUL PHILIPS

1

API 510- PRESSURE VESSEL INSPECTOR COURSE

VOLUME-1 CONTENTS PROGRAM SCHEDULE PART I - CERTIFICATION INFORMATION FROM API. PART II - GUIDELINES FOR CLEARING API 510 EXAMINATION PART III - CODE WISE PUNCH POINTS PART IV- CASE STUDIES, PART V -

WPS/POR ROAD-MAP AND REVIEW

PART VI - ADDITIONAL INFORMATION PART VII - QUESTION BANK : QUESTIONS ON API 510 CODE PART VIII - QUESTION BANK : QUESTIONS ON ASME CODES PART IX - QUESTION BANK : QUESTIONS ON RECOMMENDED PRACTICES

PAUL PHILIPS

2

API 510- PRESSURE VESSEL INSPECTOR COURSE

PROGRAM SCHEDULE DAY 1: MODULE – 1 Welcome and Introduction Overview of API 510 Course Examination Methodology Introduction to ASME Sec. VIII Div.1

MODULE – 2 JOINT EFFICIENCIES a. Weld Joint Categories from UW-3; b. Type of radiography (full, spot, or none , RT-1, RT-2, etc.); c. Joint efficiency by reading Table UW-12; d. Joint efficiency for seamless heads and vessels Sections per UW-12 (d); and e. Joint efficiency for welded pipe and tubing per UW-12 (e).

MODULE - 3 THICKNESS CALCULATIONS a) The required thickness of a cylindrical shell (UG-27(c)(1)); b) The vessel part MAWP for a cylindrical shell c) The required thickness of a head-Hemispherical, Ellipsoidal, Torispherical d) The vessel part MAWP for a head

DAY 2: MODULE - 1 STATIC HEAD c) Calculate static head pressure on any vessel part; d) Calculate total pressure (MAWP + static head) on any vessel part; e) Calculate maximum vessel MAWP given vessel parts MAWP and elevations

PAUL PHILIPS

3

MODULE -2 EXTERNAL PRESSURE a) Calculate the maximum allowable external pressure; b) Calculate whether a cylindrical shell meets Code design for external pressure. IMPACT TESTING a) Determine the minimum metal temperature of a material which is exempt from impact testing (UG-20 (f), UCS-66,UCS-68(c).)

MODULE - 3 PRESSURE TESTING a) Calculate a test pressure compensating for temperature. (UG-99 & UG-100) b) The precautions associated with hydrostatic and pneumatic testing, c) Steps in a hydrotest Procedure (UG 99 and UG 100) d) All steps in a pneumatic test procedure (UG 100 and UG 102)

DAY 3: MODULE - 1 WELD SIZE FOR ATTACHMENT WELDS AT OPENINGS a) Conversion of a fillet weld throat dimension to leg dimension , conversion factor(0.707) b) Determine the required size of welds at openings (UW-16).

MODULE – 2 NOZZLE REINFORCEMENT Key concepts of reinforcement, such as replacement of strength and limits of reinforcement. Credit for extra metal in shell and nozzle Calculate the required areas for reinforcement

MODULE – 3 a) Typical joints and definitions b) Weld sizes c) Restrictions on joints d) Maximum allowable reinforcement e) Inspection requirements f) Heat treatment

PAUL PHILIPS

4

DAY 4:. MODULE - 1 1 SCOPE 1.1 General Application 1.2 Specific Applications 1.3 Recognized Technical Concepts 2 references

MODULE - 2 3 definitions 4 owner/user inspection organization 4.1 General 4.2 Owner/user Organization Responsibilities

MODULE - 3 5 inspection, examination and pressure testing practices 5.1 Inspection Plans 5.2 Risk-based Inspection 5.3 Preparation For Inspection 5.4 Inspection For Types Of Damage Modes Of Deterioration And Failure

DAY 5 : MODULE - 1 5.5 General Types Of Inspection And Surveillance 5.6 Condition Monitoring Locations 5.7 Condition Monitoring Methods

MODULE - 2 5.8 Pressure Testing 5.9 Material Verification And Traceability 5.10 Inspection Of In-service Welds And Joints 5.11 Inspection Of Flanged Joints

PAUL PHILIPS

5

MODULE - 3 6 interval/frequency and extent of inspection 6.1 General 6.2 Inspection During Installation And Service Changes 6.3 Risk-based Inspection 6.4 External Inspection 6.5 Internal And On-stream Inspection 6.6 Pressure-relieving Devices

DAY 6: MODULE - 1 7 inspection data evaluation, analysis, and recording 7.1 Corrosion Rate Determination 7.2 Remaining Life Calculations 7.3 Maximum Allowable Working Pressure Determination

MODULE - 2 7.4 Fitness For Service Analysis Of Corroded Regions 7.5 API RP 579 Fitness For Service Evaluations 7.6 Required Thickness Determination 7.7 Evaluation Of Existing Equipment With Minimal Documentation 7.8 Reports And Records

MODULE - 3 8 repairs, alterations, and rerating of pressure vessels . 8.1 Repairs And Alterations Authorization Approval Materials Requirements Welding Requirements

PAUL PHILIPS

6

DAY 7: MODULE - 1 Heat Treating Requirements, Preheating Post weld Heat Treating Local Postweld Heat treatment Repairs to Stainless Steel Weld Overlay and Cladding Rerating .

MODULE - 2 Introduction to ASME Sec. IX Welding Procedure tests Performance qualification tests Acceptance criteria Welding positions P-No, F-No and A-No.

MODULE - 3 Review of: a. Welding Procedure Specification (WPS); and b. Procedure Qualification Record (PQR). And determine: a) Whether number and type of mechanical test listed on PQR are appropriate b) Whether the results of the tests are acceptable c) Whether all required essential and non-essential variables have been properly addressed.

DAY 8: MODULE - 1 A. Article 1, General Requirements: B. Article 2, Radiographic Examination:

MODULE - 2 C. Article 6, Liquid Penetrant Examination, D. Article 7, Magnetic Particle Examination (Yoke and Prod techniques only): E. Article 23, Ultrasonic Standards, Section SE–797

PAUL PHILIPS

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MODULE - 3 API RP 571, Damage Mechanisms Affecting Fixed equipment in the Refining Industry Par. 4.2.3 – Temper Embrittlement 4.2.7 – Brittle Fracture 4.2.9 – Thermal Fatigue 4.2.14 – Erosion/Erosion-Corrosion 4.2.16 – Mechanical Failure 4.3.2 – Atmospheric Corrosion 4.3.3 – Corrosion Under Insulation (CUI)

DAY 9: MODULE - 1 API RP 571 4.3.4 – Cooling Water Corrosion 4.3.5 – Boiler Water Condensate Corrosion 4.4.2 – Sulfidation 4.5.1 – Chloride Stress Corrosion Cracking (Cl-SCC) 4.5.2 – Corrosion Fatigue 4.5.3 – Caustic Stress Corrosion Cracking (Caustic Embrittlement) 5.1.2.3 – Wet H2S Damage (Blistering/HIC/SOHIC/SCC) 5.1.3.1 – High Temperature Hydrogen Attack (HTHA)

MODULE - 2 API RP-572, Inspection of Pressure Vessels 1. Types and Definitions of Maintenance Inspections 1. Maintenance Inspection (API RP-572, Section 6) 2. Reasons for Inspection (API RP-572, Section 7) 3. Causes of Deterioration (API RP-572, 8.1 – 8.5) 4. Frequency and Time of Inspection (API RP-572, Section 9)

MODULE - 3 1. 2. 3. 2.

Internal Inspection (API RP-572, 10) External Inspection, Typical Items Checked (API RP-572, 10.3) Thickness Measurements and Limits (API RP-572, Section 10) Inspection Records and Reports (API RP-572, Section 12)

PAUL PHILIPS

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DAY 10 : MODULE - 1 API RP 576, Inspection of Pressure-Relieving Devices a) Description of Types -- (API RP-576, Section 2) b) Causes of Improper Performance (API RP-576, Section 4) c) Reasons for Inspection and Frequency Determination (API RP 576, Sections 3 & 5) d) Inspection and Test Service Procedures (API RP-576, Sections 6 and 7)

MODULE - 2 API RP 577, Welding Inspection and Metallurgy 1. Definitions 2. Welding Inspection 3. Welding Processes 4. Welding procedure 5. Welding Materials 6. Welder qualifications 7. Non-destructive examination 8. Metallurgy 9. Refinery and Petrochemical Plant Welding Issues

MODULE – 3 Practice Examination-Open Book Practice Examination-Closed Book Feed Back and Closing Session

PAUL PHILIPS

9

API 510- INSERVICE PRESSURE VESSEL INSPECTOR PREPARATORY COURSE

PART I

CERTIFICATION INFORMATION FROM API.

PAUL PHILIPS

10

API 510- INSERVICE PRESSURE VESSEL INSPECTOR PREPARATORY COURSE

PART II

GUIDELINES FOR CLEARING API 510 CERTIFICATION EXAMINATION SUCCESSFULLY

1 IET/CH/TP/002-R02, Sept.11

API 510 CERTIFICATION FOR IN-SERVICE INSPECTION GUIDELINES FOR CLEARING API 510 EXAMINATION SUCCESSFULLY

INTRODUCTION Pressure Vessels are a major installation in Petroleum Refineries, Petrochemical plants, Oil terminals and other process plants. They store variety of fluids, which may be Explosive, Corrosive or Toxic in nature. The equipments are also subjected to high pressures and moderate to elevated temperatures. All these factors may cause corrosion and other damages to the vital equipments. The corrosion may cause thinning, pitting or cracking of pressure vessel wall. The internal pressure will tend to bulge the piping at the corroded locations, releasing the explosive or toxic contents resulting in serious consequences to the plant, personnel and the people at large. It is therefore essential that during the planned shutdowns, the degradation and damages inflicted to the Plant equipment, Pressure Vessels, Piping and Tanks should be monitored and evaluated so as to arrive at the ‘3R’ decisions. i.e. “Run-RepairReplace” decisions. More specifically, this course describes the essentials of what to inspect, where to inspect, how much to inspect and what to accept so as to evaluate the safety and mechanical integrity of in-service Pressure Vessels. The course also covers methods of repair, alteration, re-rating and replacements of affected Pressure Vessels. The API Courses provide the participants the guidelines and methodology of carrying out inspection of “in-service” equipments. It also provides techniques for the assessment of the wear and tear of the equipments as well as to 2 IET/CH/TP/002-R02, Sept.11

measure de-gradation and damages caused to the process equipments due to the process conditions. If the assessment indicates that the equipment is safe to run, the participants are further taught how to estimate the safe remaining life and the methods to extend the useful life of the equipments. If the decision is that the equipment needs repair, the course teaches the participants, how to carry out such repairs of the damaged part without causing damage to the whole equipment. It also covers the methods of rerating the equipment by evaluating the mechanical integrity if it is not possible to restore the equipment to its original design conditions.

COURSE OBJECTIVES This examination preparation course is designed to prepare the participant to successfully sit for the API-510 exam. Through your concentrated effort, and the material provided in this course, you should have sufficient information to pass the examination. The majority of the classroom study will focus on the Body of Knowledge . The goal, is to obtain a perfect score. Therefore please take your daily classroom activity and assigned homework seriously. The material contained in this manual is to be thoroughly studied and practiced prior to attending the course. The math examples and practice problems are based on the types of questions given on the API-510 exam. Through the use of these examples, you will be exposed to many of the formulas used during the course. Remember, this is a very intense course. There will be eight hours of classroom study each day. The instructor will be available to answer questions or to assist any participant having difficulty with the homework assignments or any topic discussed during class. There will be from two to three hours of 3 IET/CH/TP/002-R02, Sept.11

homework assignments each day. Daily quizzes are given and one practice API-510 examination is provided. The pace is fast and focused. The participant is responsible for making all arrangements for taking the examination including confirming your eligibility and applying to the American Petroleum Institute. No reference material of any kind will be permitted during the closed book portion; some examining proctors may permit language translation dictionaries. There will be some common knowledge mathematical questions on the practical portion of the exam - remember to have your calculator available for this part of the exam. During this course, we will attempt to duplicate actual examination conditions including using a separate answer sheet during the practice examination.

WEIGHTAGE OF MARKS As per the Effectivity Sheet for API 510 exam, there are total 8 codes prescribed for examination. However, all of them are not equally important and do not therefore require equal emphasis. About 50 percent questions are asked from one code API 510 which is hardly 40 pages, while all other 6 codes contribute 50% marks which are more than 1,000 pages. Following distribution scheme will help the participant to decide how much time he should spend for each document during preparation. Note: The weightage indicated is approximate and for guidance only.

4 IET/CH/TP/002-R02, Sept.11

A . API Publications: API 510, Pressure Vessel Inspection Code………………………….50 % API RP 571, Damage Mechanisms……………………………………..3 % API RP 572, Inspection of Pressure Vessels………………………..8 % API RP 576, Inspection of Pressure-Relieving Devices…………5 % API RP 577, Welding Inspection and Metallurgy…………………3 % B. ASME Publications: Section V, Nondestructive Examination……………………………8 % Section VIII, Division 1, Pressure Vessel Code………………….20 % Section IX, Welding and Brazing Qualifications………………..8 %

API 510: TIPS FOR MAXIMIZING EXAMINATION SCORE a.

From Chapter 1, just note the scope, application and exclusions. Chap. 2 lists only the reference documents.

b.

There are only 12 or 16 important definitions out of total 62 from Chapter 3 of API 510. Normally 3 to 4 definitions are asked in closedbook exam.

c.

From Chapter 4, usually 2 or 3 questions are asked. Concentrate on responsibilities

clause.

Also

see

App.

B

for

certification

requirements. d.

From Chapter 5, about 15-18 questions are asked. About 10-12 in closed book and 4-6 in open book.

e.

From Chapter 6, about 15-18 questions are asked. Particularly pay attention to Inspection intervals, which attracts at least 5 to 6 questions and they could be either open book or closed book. 5

IET/CH/TP/002-R02, Sept.11

f.

From Chapter 7 also 15-18 questions are asked. This is only five page chapter and almost all paras should be studied thoroughly.

g.

From chapter 8 more attention to be provided on all repair techniques and approval authorization part. There may be 3 or 5 questions on this chapter.

h.

There may be 2 or 3 questions on overall API-510 code for the purpose of assessing the overall under standing of code.

i.

Chapter 9 as well as App. E are excluded from examination.

j.

As regards ASME Sec. V and IX, the course content is categorized in 10 categories. 8 of them are listed under calculations while 9 and 10 are listed under welding and NDT. You may expect at least one open book and one closed book question on each of these. Additionally, under the category internal pressure, you may expect 4 open book questions one each for thickness calculation for the 4 types of end closures.

6 IET/CH/TP/002-R02, Sept.11

TIME MANAGEMENT DURING EXAM: Both “open” and “closed” book sessions are 4 hours each. This means about 25 to 28 questions per hour for closed book and 12 to 15 questions per hour for open book. For proper time management following are useful suggestions. a) You may start from Question No. 1 and proceed. If after 1 hour you feel that you are maintaining the required progress as mentioned above proceed serially. b) If, however, you are behind the required rate, start jumping the questions, i.e., start attempting those questions you can answer, deleting whose answer you do not know. Proceed like this till the end. Do not leave any question unanswered whose answer you know. c) Then come back to “deleted” questions and attempt them using your “feel” factor. Go on like this till say last 10-15 minutes are remaining. d) If there are still some questions where you have no clue at all just mark the answer at random in last 10-15 minutes. This may give you few chance marks. Do not leave any question un-attempted. e) After completion of writing exam, if you have still time (which you normally have) you may go through your answers just to check quickly if you have filled a wrong circle.

7 IET/CH/TP/002-R02, Sept.11

API 510- INSERVICE PRESSURE VESSEL INSPECTOR PREPARATORY COURSE

PART III

CODE WISE PUNCH POINTS SUMMARY OF ALL CODES AND STANDARDS FOR API 510) EXAMINATION

8 IET/CH/TP/002-R02, Sept.11

API 510 CERTIFICATION – PREPARATORY COURSE

API 510 - Pressure Vessel Inspection Code Note: Figures in parenthesis give the reference number of code paragraphs from where the punch points are drawn up.

A

Section 1 : Scope of API 510 1. API 510 covers in-service inspection, repair, alteration and rerating activities for pressure vessels and Pressure Relief Devices protecting the vessel. (1.1.1) 2. API 510 applies to all Refining and chemical process vessels that have been placed in service. 3. API is applicable to vessels constructed in accordance with applicable

construction

code,

or

constructed

used

in

conflict

without

a

construction code (1.1.2) 4. API

510

shall

not

be

with

regulatory

requirements. If API 510 code requirements are more stringent than regulation, then requirements of the code shall govern (1.1.3) 5. Following are excluded from API 510 (1.2.2) a.

Vessels on movable structures.

b.

All exemptions listed in ASME Sec. VIII (Div. 1)

c.

Very small vessels with certain limitation of volume and pressure.

9 IET/CH/TP/002-R02, Sept.11

B

Section 2 : References.

6.

Important reference documents which have been referred in

API 510: a.

API 571

:

Damage Mechanisms

b.

API 572

:

Recommended

Practice

for

pr.

vessel inspection c.

API 576

:

Inspection of Pr. Relief Devices.

d.

RPI RP 577

:

Welding inspection & Metallurgy.

e.

API RP 578

:

Material Verification program

f.

API 579

:

Fitness for service ( FFS).

g.

API 580

:

Risk Based Inspection (RBI).

h.

API Publ. 2201

: Procedures for welding or Hot tapping on the equipment in service.

C

Section 3 : Definitions. This chapter gives definitions.

7.

Alteration : A Physical change in any components affecting the design (3.2)

8.

Authorised inspection agency : Any one of the following (3.6) a.

Inspection organisation of jurisdiction.

b.

Inspection organisation of insurance company

c.

Inspection organisation of owner - User.

d.

Organisation or individual under the contract with owner user.

9.

Examiner : A person who assists the inspector by conducting specific NDE (3.20)

10.

Engineer : One or more persons evaluating mechanical and material characteristics (like strength calculations, corrosion, the vessel integrity etc.) (3.19)

10 IET/CH/TP/002-R02, Sept.11

11.

Repair : Work necessary to restore a vessel suitable for safe operation at design conditions. Any work not specifically conditions. Any work not specifically considered as alteration is considered repair.

12.

13.

Repair organisation : Any one of following (3.54) a.

Holder of ASME Stamp (e.g., U Stamp)

b.

Holder of R Stamp

c.

Owner user who repairs his own equipment.

d.

Sub-contractor appointed by owner user for repair jobs.

e.

Organisation authorised by jurisdiction.

Rerating : A change in either design temperature, the MDMT or MAW rating of vessel. (3.56)

14.

Condition Monitering locations are designates areas on vessel where periodic examinations are conducted (3.9)

D

Section 4 : Organisation and Responsibility.

15.

Owner / User holds overall responsibility for all activities under API 510 (4.1).

16.

Before implementing API 510, the owner / user organization should prepare quality assurance manual describing inspection and control activities (4.2.1).

17.

Engineer is responsible to owner user for design, engineering review, analysis and evaluation of pressure vessels. (4.2.2)

18.

Inspector is responsible to owner user to assure that NDE testing activities meet API 510 requirements. All NDE results must be evaluated by inspector. (4.2.4)

19.

Examiner

shall

perform

NDE

in

accordance

with

job

requirement (4.2.5)

11 IET/CH/TP/002-R02, Sept.11

20.

Repair organization is responsible to owner user and shall provide materials, equipment, quality control and workmanship as required for repair activities. (4.2.3)

E

Section 5 : Inspection Examination and Testing.

21.

Before taking up any inspection, an inspection plan shall be developed by inspector or Engineer (5.1.1).

22.

A

RBI

assessment

determines

Risk

by

combining

the

probability and the consequence of failure (5.2) 23.

RBI assessment shall be preformed in accordance with API 580. The detailed RBI methodology is presented in RBI 581 (5. 2)

24.

Before performing any inspection inspector should review the prior inspection results. (5.3.4)

25.

Internal inspection is preformed by inspector. The primary goal of internal inspection is to find damage that can not be found by regular monitoring of external CMLS. (5.5.2.1)

26.

On-stream inspection may be used as alternative to internal inspection under certain conditions. It shall be conducted by either Inspector or examiner. It may include several NDE techniques to check for various types of damages. (5.5.3)

27.

External Inspection is essentially visual inspection conducted externally to check for leakage, hot spots, vibration distortion etc. It is normally conducted by inspector but may also be conducted by other qualified persons. (5.5.4)

28.

CUI inspection is required for insulated vessels where moisture ingress is likely and vessels operate between 100 F to 3500 F for carbon and alloy steels and 1400 F to 4000 F for Austenitic Stainless Steels (5.5.6)

12 IET/CH/TP/002-R02, Sept.11

29.

Thickness measurement is usually done by UT techniques. (5.7.2)

30.

Ultrasonic Scanning or profile radiography is preferred where corrosion is localized (5.7.2)

31.

Pressure test is conducted if inspector believes it is necessary after the repairs. Pressure text is normally required after an alteration. (5.8.1)

32.

Hydrostatic Test Pressure on vessels is as follows (5.8.2) a. For vessels constructed prior to 1999 = 1.5. X MAWP X stress ratio. b. For vessels constructed after 199 = 1.3 X MAWP X stress ratio.

33.

The pressure test temperature shall be above (5.8.6). MDMT + 100 F for vessel thickness upto 2" and MDMT + 300 F for vessels thicker than 2".

F

Section 6 : Inspection Frequency.

34.

External Inspection frequency shall not exceed lesser of internal inspection interval or 5 years. (6.4.1)

35.

Internal and on-stream inspection frequency shall not exceed lower of one-half the remaining life or 10 years. If remaining life is less than 4 years inspection interval may be full remaining life up to a maximum of two years. (6.5.1)

36.

ARBI assessment may be used to establish appropriate inspection interval for internal on stream and external inspection and 10 years limit may be exceeded. (6.3.1)

37.

If service conditions of a vessel are changed inspection intervals shall be established for new service condition. (6.2.2)

13 IET/CH/TP/002-R02, Sept.11

38.

If both ownership and location of vessel are changed, Allowable Service Conditions and inspection interval shall be established. (6.2.2)

39.

On stream - inspection may substituted for internal inspection if the inspector approves, for following conditions. (6.5.2) a. General corrosion rate is less than 5 mpy as confirmed for at least 5 years. b. vessel remaining life in at least 10 years. c. vessel is not operating in creep temperature range. d. vessel is not subject to SCC. e. vessel does not have non integral lining inside.

40.

For Multi zone vessels each zone shall be inspected based on interval for that zone. (6.5.3)

41.

Pressure-Relieving devices shall be tested in accordance with API 576 (6.6)

42.

The repair organization for PRDS shall have a documented quality control system. (6.6.1)

43.

The

repair

organization

shall

have

documented

training

program to ensure that personnel are adequately qualified required (6.6.1) 44.

Testing and inspection interval for PRD s. a.

Five years for typical service.

b.

Ten years for clean and non-corrosive service. (6.6.2)

14 IET/CH/TP/002-R02, Sept.11

G

Section 7 : Inspection data evaluation.

45.

Corrosion rate (7.1)

Long term corrosion rate = t initial – t actual years between t initial & t actual. Short term corrosion rate = t previous – t actual years between t previous & tactual.

46.

Out of long-term and short-term corrosion rates the inspector in consultation with corrosion specialist shall select the rate that best reflects current conditions (7.1.1.2)

47.

For newly installed vessel or for change or service corrosion rate can be estimated based on : (7.1.2) a. Data collected on vessels in same or similar service. b. corrosion rate may be estimated from published data. c. If there is not data on any of above on-stream determination after 1000 hours of service shall be made.

48.

Remaining life = t actual – t required corrosion rate (7.2.1)

49.

MAWP determination (7.3.1) The thickness (t) used for MAWP formula is given by t = tactual - 2 (corrosion rate X Interval)

50.

For evaluation of locally thinned are corrosion averaging may be done over a length (L) not exceeding following (7.4.2.1) a.

For vessel I.D. upto 60", L=lesser of ID or 20" 2

b.

For vessel I.D. above 60", L=lesser of ID or 40" 3

51.

Pitting Evaluation (7.4.4)

15 IET/CH/TP/002-R02, Sept.11

Widely scattered pits may be ignored if all of the following are true. a. Remaining thickness below the pit is greater than one-half or required thickness. b. Total pitted area (i.e. deeper than corrosion allowance) does not exceed 7 sq. in c. Sum of pit dimension that is deeper than corrosion allowance along any 8 inch straight live does not faced 2 inches.

52.

If a vessel with joint efficiency less than 1 has corroded surface away from the weld, an independent calculation using weld joint factor = 1 can be made. Surface away from weld means surface beyond 1 inch on either side or twice the required thickness which ever is greater, as measured from toe of the weld. (7.4.5)

53.

To recalculate required thickness for tori-spherical head use following guideline (7.4.6) a. For knuckle region use thickness formula in construction code. b. For central portion use Hemispherical head formula with crown radius equal to O.D. of shell. c. Central portion is defined as center of head with diameter equal to 0.8 times shell diameter.

54.

To recalculate the required thickness for 2:1 ellipsoidal head use following guide line. (7.4.6) a.

For Knucle region use construction code formula.

b.

For central portion use Hemispherical head formula with crown radius equal to 0.9 times the inside shell diameter.

c.

Central portion is defined as center of head with diameter equal to 0.8 times shell diameter. 16

IET/CH/TP/002-R02, Sept.11

55.

If exact material specification for carbon steel unknown, then use allowable stress value (s) for S.A 2836 Gr. C material (7.7).

56.

If extent or radiography done originally is not known (E is unknown) then for butt welds use E=0.7 (7.7).

57.

Typical

pressure

vessel

records

consist

of

4

types

of

information. a.

Construction and design information.

b.

Inspection History.

c.

Repair, Alteration, re-rating information.

d.

Fitness for service records.

H

Section 8 : Repairs Alteration Re-rating.

58.

Approval of repair or alteration procedures: (7.1.2) For Repairs : Inspector For Alterations : Inspector and Engineer.

59.

Authorization of repair/ alteration work on vessels complying

with a.

ASME Sec. VIII Div. 1 : Repairs by Inspector.

b.

ASME Sec. VIII Div. 2 : Both Repairs and Alteration to be authorized by Inspector and Engineer.

60.

The inspector shall approve all repair and alteration work at the hold points and after completion. (8.1.2)

61.

Materials used for welded repairs and alterations shall be of known weldable quality. Carbon or alloy steels with carbon content more than 0.35% shall not be welded.

62.

Normally temporally repairs are replaced by permanent repair at next turnaround but may remain for longer period if approved by engineer and inspector (8.1.5.1).

17 IET/CH/TP/002-R02, Sept.11

63.

Fillet welded patches may be used for making temporary repairs. (8.1.5.1.2)

64.

New fillet patch on existing fillet patch is not permitted when installing a fillet welded patch adjacent to existing fillet welded patch, distance (d) between toes of fillet weld shall not be less than d = 4 √RT

65.

d

=

Toe - to - Toe distance

R

=

Inside radius of vessel

T

=

Actual thickness of vessel wall

Full encirclement lap band are permitted by code under certain restrictions (8.1.5.1.3)

66.

Non-penetrating nozzles (including pipe caps) are permitted as permanent repairs. (8.1.5.1.4)

67.

Insert plates are accepted as permanent repairs if : a.

Full penetration butt welds are used.

b.

Welds are radiographed as per construction code.

c.

Plates shall have round corner with minimum 1 inch radius. (8.1.5.2.2)

68.

For overlay repairs filter material of lower strength than base metal is permitted if : a.

Repair thickness does not exceed 50% of required thickness.

b.

Thickness of repair weld is increased by ratio of tensile strength of base metal to tensile strength of filter.

69.

c.

Increased thickness is given 1:3 taper.

d.

Repair made with minimum two passes. (8.1.5.3.2)

For damaged S.S. cladding with base metal exposed to Hydrogen migration, before repair degassing should be done. Additionally, for P-3, P-4 and P-5 materials base metal in repair 18

IET/CH/TP/002-R02, Sept.11

area should be examined by UT at least 24 hours after completed repair. (8.1.5.4.3) 70.

For on-stream welds refer API 2201 for guidance (8.1.6)

71.

Welders and procedures used for repairs shall be qualified as per ASME Sec. IX

72.

Local PWHT is permitted instead of 3600 banding with certain precautions (8.1.6.4.1).

73.

Pre-heat method may be used as alternative to PWHT for P No. 1 and same P No. 3 and P. No. 5 materials, if impact test was required (8.1.6.4.2)

74.

NDE of welds. (8.1.7) For weld overlay and Fillet welds - PT or MT For butt - welds - Radiography as per the construction code.

75.

Re-rating calculations shall be performed by engineer. Rerating of old vessel (built prior to 1999) can be done as per latest code under certain conditions. Re-rated pressure and temperature shall be shown by additional name plate or stamping on existing name plate. (8.2)

19 IET/CH/TP/002-R02, Sept.11

ASME Sec. VIII Div. 1 (Figures in parenthesis give reference paragraph of ASME Sec. VIII. Div. 1, from where punch points are)

A.

INTRODUCTION :

1.

A pressure vessel is a container for the purpose of holding the pressure, either internal or External (U-1 a2)

2.

ASME Sec. VIII. Div. 1 contains requirements and guidance for pressure vessel materials, design, fabrication, inspection and testing (u-1 A 3).

3.

Following are excluded from scope of ASME Sec. VIII. Div. 1 (u- 1c). a.

All piping systems.

b.

All fired vessels (i.e. Boilers)

c.

Vessels with operating pressure less than or equal to 15 psig.

d.

Vessels with inside diameter less than or equal to 6 inches.

B.

Weld Category, types, joint Efficiency :

4.

"Weld joint category" defines the location of a joint in a vessel but not the type of joint. They are indicated by letters A, B, C, D (UW-3)

5.

There are 4 categories of joints (UW-3) Category A

:

All longitudinal welds in shell and nozzles.

:

All welds in Heads.

:

Circumferential weld joining Hemispherical head to shell.

Category B

:

All

circumferential

welds

in

shell

and

nozzles.

20 IET/CH/TP/002-R02, Sept.11

:

Circumferential welds joining shell to any formed

head

(other

than

Hemispherical

head) Category C

:

All Flange Welds.

Category D

:

All welds joining nozzle to the vessel shell or head.

6.

Longitudinal

welds

are

normally

full

stress

welds,

while

circumferential welds are half stress welds. 7.

Welds type are indicated by numbers (UW-12) Type 1

:

Typically

double

welded

giving

full

penetration. Type 2

:

Full penetration weld with backing strip in place.

Type 3

:

Joints welded from one side only (May or may not be full penetration weld).

8.

Table UW-12 gives weld joint efficiency to be used in thickness formulas depending on full, spot or Nil radiography.

9.

Extent of radiography is indicated, on name plate (UG-116). RT 1

:

Full Radiography (with all butt welds fully radio graphed)

RT 2

:

Full Radiography (Category a welds full length and category B spot radio graphed).

10.

RT 3

:

Spot Radiography (For both category A & B)

RT 4

:

No radiography.

Joint Efficiency for reamers for dished heads depends on radiography of shell to head weld (UW-12d).

21 IET/CH/TP/002-R02, Sept.11

11.

Joint Efficiency for welded pipes and tubes is always taken as 1 (UW-12e).

C.

Thickness of vessel components :

12.

Various

thick

nesses

for

vessel

are

defined

as

below

(Mandatory Appendix 3) a.

Required Thickness

: Thickness required for holding pressure.

b.

Design thickness

: Required

thickness

plus

corrosion allowance. c.

Nominal thickness

: Commercially available thickness as used for vessel fabrication.

13.

Required thickness of cylindrical shell having internal design pressure (P), Internal radius (R) Allowable stress (S), Joint efficiency (E) is given by (UW-27). Required thickness =

PR SE - 0.6 P

MAWP for cylindrical shell =

SE t R +0.6t.

14.

Head thickness and depths (UW - 32) a. 2:1 Ellip head : depth = ¼ D, Thk = nearly same as shell.

b. Hemispherical head : depth =

½ D, Thk = nearly half of

shell.

c. Torispherical head thickness= 1.77 times shell thk approx.

D.

MAWP Analysis :

15.

Water causes a static head pressure given by 1 ft water column = 0.433 psi.

16.

Total pressure is given by = vessel MAWP plus static head.

17.

Total at any point can not exceed vessel part MAWP for that location.

22 IET/CH/TP/002-R02, Sept.11

18.

Vessel MAWP is measured at top of the vessel. It is least value of all part MAWPS after deducting the static head on that part (UG-98a)

E.

External Pressure :

19.

Allowable external pressure on cylindrical shell is given by (UG28). Pa = 4B

(Use this formula if B is given)

3 (Do/t) Pa = 2AE

(Use this formula if A is given)

3 (Do/t)

F.

Pressure Testing :

20.

ASME code prefers Hydrostatic pressure test as standard test. Pneumatic Test may be used only if Hydrostatic Test can not be performed due to Design reasons or process reasons. (UG-99, UG-100)

21.

Standard Hydrostatic Test (UG-99) a. The

test

is

applied

after

all

fabrication

inspection

is

completed. b. Hydrostatic test pressure = 1.3 X MAWP X stress at test pr. stress at Design pr. c. Inspection pressure shall be not less than test pressure divided by 1.3 d. Test temperature = MDMT + 300 F e. Relief value Pressure = 1.1/3 times test pr. 22.

Pneumatic Test (UG-100) a. Performed only if Hydro test is not possible due to design or process reason b. Prior to test PT or MT examination of nozzle welds is mandatory to identify cracks if any as per UW-50. c. Pneumatic test pr = 1.1 X MAWP X Stress test temp. Stress at Design temp.

23 IET/CH/TP/002-R02, Sept.11

d. Test Temperature = MDMT + 300 F (shall) e. Pressurization

in

6

steps.

first

step

50%

of

test

pr

subsequent steps 10% of test pr. f. Inspection pressure shall be at test pressure divided by 1.1. 23.

Test gage range (UG-102) Ideal range 0 to twice the test pr. Min. range 0 to 1.5 times test pr. Max. range 0 to 4 times test pr.

G.

Impact Testing :

24.

For carbon and low ally steel vessels operating at low temperature,

impact

testing

requirements

of

materials

is

decided by figure UCS-66. (UCS-66) 25.

Steps in deciding impact test requirements. (UCS-66) a.

First decide curve for given material.

b.

Go to Fig. UCS-66, If MDMT-Thickness combination point is on or above the curve from (a), Impact testing not required if below, Impact test is required.

c.

If the point is close to curve, Table UCS-66 is helpful in deciding exactly whether the point is above, on, or below the curve.

d.

All base metals above 6 inch thickness and all welds above 4 inch thickness always require impact tests.

26.

If impact tests are required as per above steps, there are further exemptions possible if thickness for curve 'A' materials is less than or equal to 0.5" and for curve B, C, D thickness is less than or equal to 1 inch [UG-20(f)]

27.

For carbon steels (P No. 1) further reduction of 300 F from temperature on UCS - 66 curve can be given if PWHT was performed when it was not mandatory by code.

24 IET/CH/TP/002-R02, Sept.11

H.

Nozzle welds and Re-inforcements:

28.

The nozzle welds shall be checked for code conformance by comparing with suitable diagrams given in code (UW-16)

29.

Throat of filled weld = 0.707 X leg of weld.

30.

Nozzle

shall

be

adequately

reinforced

by

providing

the

reinforcement pad if required (UG 36 C 3) 31.

Reinforcement area must be within limits of reinforcements given by : (UG - 37)

32.

a.

Limit along vessel wall = 2 d

b.

Limit perpendicular to wall = 2.5 tn.

c.

Diameter of finished opening.

d.

tn = nozzle thickness.

Reinforcement Area required = d X tr (tr = Required thickness of shell).

33.

Extra available in vessel wall = d (t - tr.) (t = vessel shell thickness as provided.)

34.

Extra available in nozzle = 5 tn (tn - trn.) (trn = Required thickness of nozzle.)

35.

Reinforcement pad is not required if : a. nozzle opening is less than or equal to 23/8 inch. for shell thickness above 3/8 inch. b. For nozzle opening up to 3.5 inch. for shell thickness 3/8 inch. or less. (UG - 36 C 3).

25 IET/CH/TP/002-R02, Sept.11

J.

Misc. Requirements :

36.

Weld misalignment and weld reinforcements must be within code requirements (UW-33 and UW - 35).

37.

Ovality tolerance shall not exceed one percent of Nominal diameter. (UG-80)

38.

Maximum under tolerance on plates is lesser of 6% ordered thickness or 0.01 inch i.e. 0.25 mm (UG-16 C).

39.

For welding unequal thickness, a taper transition of 1:3 must be provided i.e. taper length = 3 times plate offset (UW -9).

40.

PWHT

requirement depends

on

P

No.

of

material

and

thickness. The minimum holding temperature and holding time shall be as per tables UCS-56 for various P. Nos. (UCS-56).

26 IET/CH/TP/002-R02, Sept.11

ASME - Sec. IX - welding Qualification Code

Note : Figures in parenthesis give reference cause in the code. 1.

ASME Sec. IX gives requirement for Qualifying Procedures and welders (QW 100).

2.

For Procedure Qualifications a test coupon is welded and then tested for strength (tension tests) and ductility (Bend tests) to ensure that the weld has required properties (QW- 141).

3.

In performance qualification we determine welder's ability to produce sound welds by conducting either Bend tests or Radiography. (QW 141, 142)

4.

Tension test is passed if either of the following is satisfied. a. If break is in weld metal is must be at strength above the specified minimum tensile strength of Base metal. b. If break is in base metal it must meet at least 95% of minimum tensile strength of Base metal. (QW 153).

5.

Bend test (It may be Face bend, root bend or side bend) is passed if test specimen does not show open discontinuity more than 1/8 inch. (3 mm.) (QW 163).

6.

Radiography for welder qualification shall meet acceptance criteria of ASME Sec. IX (QW 191.2).

7.

A PQR is a record of welding data used to weld test coupon. It also contains test results on backside it can not be revised. (QW 202.2)

8.

A WPS is used to provide direction for making production welds. It shall be within ranges qualified by P & R (QW 200.1)

27 IET/CH/TP/002-R02, Sept.11

9.

A P & R support WPS as long as essential variables on both are same.

10.

For P & R test to pass it shall pars 2 tension tests and 4 bend tests (QW 202).

11.

Bend tests are 2 face Bend and 2 Root bends for coupon thickness less than 3/4" (19 mm) and 4 side bend tests if thickness is equal to greater than 3/4" (QW 451)

12.

P Q R should also list P. No. (for parent metal) F.No. (for filler metal) and A-No. (for weld metal) [QW-422, QW-432, QW-442].

13.

For procedure qualification test coupon may be a plate or pipe. plate qualities for pipe and vice versa (QW 211)

14.

A procedure qualification in any position qualities the procedure in all positions. (QW-203)

15.

For welder qualification 2 bend tests or Radiography can be used (Except for GMAW - 5 process) [QW - 452] and QW 304

16.

for welder qualification position is important (QW - 461.9) Qualification Test

17.

Position Qualified

1 G (flat)

1G

2 G (Horizontal)

1G, 2 G

3 G (Vertical)

1 G, 3 G

4 G (Overhead)

1 G, 4 G

5 G (Pipe fixed)

1 G, 3 G, 4 G, 5 G

6 G (Pipe at 450)

All.

2 G and 5 G

All.

For pipe positions 5 G and 6 G qualification 4 bend tests are required and all must pass. (QW-452).

18.

If a welder passes procedure qualification test, be is also qualified for performance in that position. (QW -301.2)

28 IET/CH/TP/002-R02, Sept.11

19.

When

welder

is

qualified

by

radiography

for

plate

test

coupon, at least 6" length shall be examined by radiography and for pipe, entire weld circumference shall be examined. (QW - 302.2) 20.

Performance qualification of a welder is affected if he does not weld with a process for 6 months or more. If there is specific reason to question his ability to make acceptable welds his qualification for the welding he is doing shall be revoked. (QW322)

29 IET/CH/TP/002-R02, Sept.11

ASME Sec. V - Non destructive Examinations.

A.

General :

1.

ASME Sec. V. gives methods and requirements for conducting NDT. It becomes applicable only if referred by the other referencing codes.

2.

The user of Sec. V. Code is responsible for following. a. Getting NDT personnel properly certified. b. All NDT examinations require written procedures. c. All NDT equipments shall be as per Sec. V. d. Equipments shall be calibrated as required by Sec.V. e. Records retention.

B.

RT Examination :

3.

For RT Examination, either hole type or wire type IQI shall be used.

4.

A radiograph is considered satisfactory, if it is within the density limits and has required IQI image. For hole type 2 T hole and for wire type the designated wire image shall be seen.

5.

Density limitation : 2 to 4 for Gamma Rays. 18 to 4 for X rays. Density variation permitted = +30% to - 15%

6.

Selection of IQI is based on weld thickness plus the weld reinforcement. Thickness of backing strip is excluded.

7.

IQI is normally placed on Source side unless inaccessibility prevents it. They IQI may be placed on Film side and a Lead letter F shall be put adjacent to it.

30 IET/CH/TP/002-R02, Sept.11

8.

Hole IQI may be placed on or near the weld. Wire IQI is placed on the weld with wires perpendicular to the weld axis.

9.

Double wall double image technique is suitable for pipes up to 3.5" OD.

10.

Back scatter shall be avoided. If light image of Lead Letter - B is seen on dark background then the backscatter is excessive and radiograph shall be rejected.

C.

PT Examination.

11.

For conducting PT on certain materials, the contaminants shall be controlled as follows. a. For Nickel and its alloy : Sulpher content not to exceed 1% of residue. b. For Austenitic S.S. Duplex S.S. and Titanium content of chlorine plus Florien shall not exceed 1% of residue.

12.

Two type of penetrates (visible and Fluorescent) can be used. For excess penetrate removal 3 methods are used for visible and fluorescent. -

Water washable

-

Post Emulsifying.

-

Solvent Removable.

This results in total 6 techniques. 13.

PT is normally conducted between temperatures 500 to 1250 F (100 to 520 C). For below or above this range special penitents shall be used and the dwell time should be worked at using quenched Aluminum blocks.

14.

After applying the developer, interpretation shall be done within 10 to 60 minutes.

31 IET/CH/TP/002-R02, Sept.11

15.

Intermixing of penetrate material from different families (i.e. visible & fluorescent) or penetrate materials from different manufacturers are not permitted.

D.

MT Examination :

16.

The Magnetic Particle Examination can be performed on Ferromagnetic materials for finding surface and near surface defects. Drug or wet Iron powder and visible, or fluorescent powder is used.

17.

Prod Technique used Direct current. The distance between prods shall be 3 inches to 8 inches. This is suitable for finding surface and near surface defects.

18.

Yoke technique is suitable for surface defects only and can use A.C., D.C. or permanent magnet.

19.

Ammeter

on

instrument

shall

be

calibrated

annually

by

comparing 3 current readings with a standard Ammeter, and permitted tolerance is + 10% of full scale. 20.

For yoke, the electromagnetic yokes shall be calibrated annually by checking lifting power. A.C. yoke shall lift 10 pounds (4.5 kg.) D.C. yoke shall lift 40 pounds (18 kg.)

21.

Lifting power of permanent magnet yoke shall be checked daily prior to use by lifting 40 pounds (18 kg) weight.

22.

Examination is performed in two perpendicular directions.

32 IET/CH/TP/002-R02, Sept.11

E.

UT Examination :

23.

Pulse - Echo contact method is used for finding thickness and laminations.

24

In Direct contact (single element) method is not suitable for smaller thickness hence delay line method is used which uses a delay block to delay the echo.

25.

In delay line, end of delay is made to coincide with Zero thickness on CRT.

26.

Dual Search units are also used using two crystals one for sending pulse and other for receiving echo. On smaller thickness

this

method

results

in

vee-error

which

needs

correction. 27.

For thick section measurement use of multiple echo technique is made. The calibration block chosen is smaller thickness which will permit standardizing the full-sweep distance to adequate accuracy on CRT.

28.

For measurement at high temperatures thickness correction is needed. A positive error of 1% per 1000 F increase in results.

33 IET/CH/TP/002-R02, Sept.11

API RP 572 - Inspection of Pressure Vessels.

1.

API 572 covers guide lines for conducting detailed inspection of pressure vessels.

2.

Basic reasons for inspection are to determine the physical condition of the vessel and to determine type rate, and causes of degradation and damage. A good timely inspection results is safety, continuity and reliability of the plants equipments.

3.

Creep damage depends on time, temperature

& applied

stress. 4.

Graphitization may take range

o

o

of 825 f

carbide Graphite

please due

to 1400 f

decomposes to produce noodles

strength steel .

( pure

In-situ

to long exposure o

o

( 440 C to 760 f ferrite

carton ). This

in which

( pure iron ) causes

metallography is useful

in

and

loss of

in detecting

Graphitization . 5.

De alloying is selective leaching or loss of one or more alloy components example. Dezincification of copper-zinc (brass) alloy.

6.

Hydriding of titanium alloys is that Titanium alloys may become brittle (lose ductility) due to absorption of Hydrogen.

7.

External inspection starts with platform and ladders, which is mostly visual and supplemented by hammer test.

8.

Anchor bolts may be checked by sideway blow with hammer.

9.

Grounding connection should be checked for good electrical contracts and the resistance. Recommended resistance is 5 ohms or less but shall not exceed 25 ohms in any case. 34

IET/CH/TP/002-R02, Sept.11

10.

Vibrations of auxiliary equipments (pressure gauges, right glass etc.) should be arrested by adding support or vibration analysis should be done to make sure that fatigue failure will not occur.

11.

External distortion may be measured by taking measurements from a parallel line (typically a stretched wire) to vessel wall.

12.

During internal inspection cracks are likely to be found in weld and HAZ particularly at nozzle welds if following factors are present (more factors present means more susceptibility.) a.

Heavy wall vessel.

b.

Hydrogen or Hydrocarbon service.

c.

Wet H2S service,

d.

Caustic or Amine service.

e.

material with coarse grain structure.

f.

High strength materials.

g.

Low-chrome materials.

Best method to check internal cracks is WEMT. 13.

Areas directly above and below the liquid level in vessels containing acidic corrodants are subject to Hydrogen Blistering.

14.

Laminations appear similar to cracks. Laminations run slant to surface while cracks run at right angles.

15.

Corrosion of Metallic lining can be monitored using corrosion tabs made from lining material and welded at right angles.

16.

Where a lining leaks, whether corrosion has taken place behind it can be determined by taking VT thickness measurement from outside.

17.

Non metallic lining are typically inspected visually or by High voltage spark testing also known as Holiday detection.

35 IET/CH/TP/002-R02, Sept.11

API RP 576 - Inspection of Pressure Relieving devices

1.

API 576 describes inspection and repair practices for Pressure Relieving

Devices

(PRDs).

It

does

not

cover

training

requirements for mechanics involved in inspection & repair of PRDs. 2.

Difference between Release Pressure and set pressure is known as Overpressure and difference between set pressure and closing pressure is called Blow down.

3.

Cold differential test pressure (CDTP) is the test bench set pressure.

It

includes

correction

for

back

pressure

&

temperature. 4.

Safety valves are used on compressible fluids (Gases, Vapors) and Relief valves are used an incompressible fluids (liquids).

5.

Safety Relief valve works as Safety valve if installed on gases and vapors. I works as Relief valve if installed on liquids.

6.

Conventional Safety Relief valve operation is directly affected by changes in back pressure.

7.

Balanced Safety Relief valve incorporates a bellow or other devices to minimize effect of back pressure on operation. This valve is suitable when the discharge from valves must be piped to remote location.

8.

Pilot operated valves are PRDs in which the main valve is combined with and controlled by a auxiliary valve (pilot).

9.

Rupture discs are used to protect the PRD against corrosion or plugging due to system fluid.

36 IET/CH/TP/002-R02, Sept.11

10.

Conventional Rupture Disk is designed to burst when it is overpressured on concave side. It provides satisfactory service for operating conditions withe 70% or less of the rated burst pressure.

11.

Reverse acting rupture disc is designed to burst when it is overpressure on convex side. They use bursting device like knife blade or shear rings. They can be used for operating conditions up to 90% of rated burst pressure.

12.

Transportation of pressure Relief valves (PRV) should be in upright position.

13.

The PRV should be installed directly on the vessel and it should not be connected by lengthy piping to avoid chattering of valve.

14.

As soon as the valve is received in shop and mounted on test block "as received" pop pressure shall be noted.

15.

After "as received" pop test valve is visually inspected, decision on dismantling the valve is taken. If pop test and visual are ok, normally there is no need to dismantle the valve.

16.

After re-assembly the valve pop pressure is checked. The deviation of pop pressure from set pressure shall not exceed.

17.

a

+ 2 psi for pressures up to 70 psi.

b.

+ 3% for pressures above 70 psi.

Valve is also tested for leak tightness at a pressure equal to 90% of CDTP, by bubble test method.

18.

The Maximum inspection and testing interval is 10 years.

19.

Visual on-stream inspection which is like a survey (to check that correct valve is at correct location, correct tag is at correct valve, valve is not leaking, valve operation is not obstructed etc). This survey shall be conducted at a interval not more than 5 years.

37 IET/CH/TP/002-R02, Sept.11

API RP 571 - Damage Mechanisms.

1.

Temper embrittlement is reduction in toughness in low alloy chromium steels due to long exposure in high temperature range (6500 F to 11000 F).

2.

Common way to minimize temper embrittlement is to limit "J" factor for base metal and "X" factor for weld metal.

3.

Brittle fracture is sudden fracture under stress due to loss of ductility at low temperature, cracks are typically, sharp straight, non-branching.

4.

Some reduction in possibility of brittle fracture may be achieved by performing PWHT.

5.

Fatigue is typically caused due to surface notch and cyclic stresses. If cyclic stress are due to mechanical reasons (rotating shaft, rapid change of pressure) it is Mechanical Fatigue. If cyclic stresses are due to changes of temperature, it is thermal fatigue. If surface notch is due to corrosion and cyclic stresses are present it is corrosion Fatigue.

6.

Thermal Fatigue cracks are dagger shaped and oxide filled.

7.

Thermal fatigue is prevented by preventing stress concentration and controlling thermal cycling.

8.

Mechanical fatigue failure typically shows "Beach-mark" or "clam shell" type concentric rings. Mechanical fatigue can be prevented by avoiding stress concentration at surface.

9.

Corrosion Fatigue can be prevented by using coatings or inhibitors or by using more corrosion resistant materials.

38 IET/CH/TP/002-R02, Sept.11

10.

Erosion-corrosion is damage that occurs when corrosion contributes to erosion by removing protective scale due to the combined action.

11.

Erosion

Corrosion

increases

with

velocity,

turbulence,

concentration of impacting medium size and hardness of impacting particles. 12.

Some methods to reduce Erosion-corrosion are increasing pipe diameter

to

increasing

reduce surface

velocity,

using

hardness,

large

using

radius

bends,

corrosion-resistant

materials. 13.

Atmospheric corrosion increases with high humidity (marine environment) and atmospheric pollution (industrial environment) and is best prevented by providing coating / painting.

14.

CUJ is caused due to water trapped under insulation, for carbon steel it may show scale formation and for S.S. it may show pitting and cracking due to chloride stress corrosion cracking.

15.

CVI may be prevented by providing protective painting and maintaining insulation is good condition to prevent the moisture entry.

16.

Cooling water corrosion is caused by dissolved salts, gases (typically oxygen) or microbes (which may be present in stagnant or low velocity water).

17.

Cooling

water

corrosion

can

be

prevented

by

chemical

treatment, maintaining flow velocity and monitoring oxygen contact in water. 18.

Boiler water corrosion is result of dissolved gases namely oxygen and carbon di oxide.

39 IET/CH/TP/002-R02, Sept.11

19.

Best method to reduce Boiler water corrosion is to use deaerator for Boiler feed water, monitoring presence of oxygen and using oxygen scavangers like Hydrazine.

20.

Chloride stress cracking corrosion is typically takes place on Austenitic Stainless steel between 1500 to 4000 F in chloride environment.

21.

Austenitic S.S. (300 Series) are most suceptible duplex stainless steels are somewhat resistant and Nickel Alloys (more than 40% Nickel) and almost immune.

22.

For Hydro-testing of Austenitic S.S. Vessels and pipes use water with low or free of chlorides (typically less than 50 ppm,)

23.

Caustic Stress corrosion cracking typically takes place on carbon steel adjacent to welds which are not stress relieved.

24.

Higher temperature and higher caustic concentration increases suceptibility.

25.

Best method to prevent caustic stress corrosion cracking is conducting PWHT of completed weld or use of Nickel alloys should be considered.

26.

Sulphidation of carbon and alloy steels typically takes place above 5000 F and increases with and sulpher concentration increasing temperature.

27.

Best method to prevent sulphidation is upgrading to higher chromium alloys.

28.

High temperature Hydrogen attack (HTHA) takes place at temperature above 4000 F due to migration of atomic Hydrogen which combines with carbide in carbon steels forming methane gas, which can not diffuse out, collects at grain boundaries and causes cracking.

40 IET/CH/TP/002-R02, Sept.11

29.

Best method to avoid use of HTMA is select materials using API RP 941 curves (Nelson curves). HTHA can be detected by metallography.

30.

Wet H2S exposure causes 4 types of damages namely Hydrogen blistering, Hydrogen induced cracking (HIC), Stress Oriented Hydrogen induced cracking (SOHIC) and sulphide stress corrosion cracking (SSC).

31.

Hydrogen blistering takes place due to migration of atomic hydrogen in steel and combining to term hydrogen molecules which

typically

collect

at

voids,

slags,

porosity

causing

Hydrogen pressure to build up and producing Hydrogen Blister. 32.

The Hydrogen blisters formed within steel at different levels will grow and combine to form Hydrogen induced cracking which typically has stepwise appearance.

33.

The HIC cracks formed within HAZ will propagate rapidly in perpendicular to surface due to loss of ductility to HAZ and due to stress this is called SOHIC.

34.

The Sulphide formed during the wet H2S exposure (Fe+ H2S FeS →2H) causes cracking under combined action of Sulphide and stress (which is caused due to internal pressure in vessel) leading to SSC.

35.

Best method to prevent wet H2S damage is use of controlled Hardness Steel (typically less than 22 HRC) and steel with low percentage of Sulpher and Phosphorous impurities (which reduces voids and porosity in steel).

36.

SOHIC and SSC can also be reduced by performing stress relieving of welds.

41 IET/CH/TP/002-R02, Sept.11

API RP 577 - Welding Inspection and Metallurgy.

1.

Recordable indications means the indications recorded on data sheet which need not exceed the rejection criteria.

2.

Reportable indications means the indications which exceed the rejection criteria. They should be recorded on data sheet and also reported to appropriate authorities to get them rectified.

3.

Any electrodes or fluxes that have become wet should be discarded.

4.

For

visual

examination

the

personnel

are

required

to

demonstrate jagger J-1 eye test annually. 5.

Direct Visual examination requires access to bring the eye within 6" to 24" from the surface at an angle not less than 300.

6-

Radiographic Film density is quantitative measure of film blackening. Clear film has zero density. Exposed film that allows 10% of light to pass has density =1. A film density of 2, 3, 4 allows 1%, 0.1 % and 0.01% of light to pars through the film respectively.

7.

Straight beam techniques are used for thickness evaluation or to check laminations. Shear wave (Angle beam) techniques are employed for finding discontinuities in welds.

8.

In UT, A-scan typically given pulse-echo display. B-scan shows a cross-sectional view of the object and C-scan shows plan view of object.

9.

The HAZ is that portion of the base metal (adjacent to the weld) that has not been melted but whose mechanical properties or

42 IET/CH/TP/002-R02, Sept.11

microstructure is altered due to heat of welding. For carbon steels HAZ includes the regions heated to greater than 13500 F (7000 C). 10.

The hardness values in HAZ for steels in Refinery service is given in Table 11 (For Carbon steels it is 200 BHN) Hardness in

11.

"Weldability" is defined as capacity of the metal to be welded under under the fabrication conditions imposed.

12.

Weldability is measured by Carbon Equivalent (CE) formula. CE= C + Mn + Cr + Mo + V + 6

13.

Typically

steels

Si + Ni + Cu

5

with

15

CE

less

than

0.35%

requires

no

preheating. CE will CE of 0.35% to 0.55% requires preheating and CE greater than 0.55% require both pre-heating and PWHT. 14.

Simplest welability tests are the strength and ductility test of weld.

15.

For qualifying welder on "GMAW - S" process bend tests shall be used instead of Radiography.

43 IET/CH/TP/002-R02, Sept.11

API 510- INSERVICE PRESSURE VESSEL INSPECTOR PREPARATORY COURSE

PART IV

CASE STUDIES NUMERICAL EXAMPLES FOR UNDERSTANDING APPLICATION OF CODE RULES

44 IET/CH/TP/002-R02, Sept.11

API 510 PREPARATORY COURSE

CASE STUDY – 1 (Thickness Calculations) ASME Sec VIII – Div. 1

Design Data for Pressure Vessel: Design Pressure = 100 psi Inside diameter = 96 inches Corrosion Allowance = 0.125 inch Shell Joint efficiency = 0.85 (spot examination) Head joint efficiency = 1.0 Allowable stress of material = 17500 psi 1.

Calculate minimum required thickness for cylindrical shell.

2.

Calculate the design thickness of shell above question.

3.

What Nominal thickness for the shell will you select, if plates are available in steps of 1/16 inch increment?

4.

Calculate shell MAWP for above cylindrical shell.

5.

Calculate required thickness for a Hemispherical Head.

6.

Calculate design thickness for Hemispherical Head.

7.

Calculate the minimum required thickness for 2 :1 Ellipsoidal head.

8.

Calculate the design thickness for 2:1 Ellipsoidal head.

9.

If dished head thickness in Question: 8 is rounded to next 1/16 inch, what will be the nominal thickness of formed head?

10.

Calculate Head MAWP for above ellipsoidal head.

11.

Calculate the minimum required thickness for a std. Torispherical head using following data: Design Pr = 100 psi, Allowable stress = 17500 psi. Head Joint efficiency = 1, Corr. Allow = 0.125”, Head Crown radius = 96 inch.

12.

Calculate design thickness for the Torispherical head in above question.

13.

If a horizontal Vessel was made using the above cylindrical shell & the ellipsoidal heads what will be Vessel MAWP for this vessel? (the static head due to contents can be ignored for horizontal vessel).

45 IET/CH/TP/002-R02, Sept.11

SOLUTION: CASE STUDY 1 DATA: P = 100 psi, R = 48.125 inch, S = 17500 psi, S = 17500 psi, E = 0.85

1.

t

=

PR SE – 0.6 P

t

=

100 x 48.125 17500 x 0.85 – (0.6 x 100)

= 0.325” required thickness = 0.325 inch

2.

Design thickness

= required thickness + corrosion allowance = 0.325 + 0.125 = 0. 450 inch

3.

Select next higher step of

1

“

16 Nominal Thickness = 0.5 inch 4.

Shell MAWP

=

SEt R + 0.6 t

Here, t = Nominal Thickness – corrosion allowance = 0.5 – 0.125 = 0.375 inch. Shell MAWP =

17500 x 0.85 x 0.375

= 115.37 psi

48.125 + (0.6 x 0.375)

46 IET/CH/TP/002-R02, Sept.11

5.

Hemispherical head thickness

t

=

PL 2SE – 0.2 P

t

=

100 x 48.125 2 x 17500 x 1 – (0.2 x 100)

= 0.138”

Required thickness = 0.138 inch

6.

Design thickness = 0.138 + 0.125 = 0.263 inch

7.

For Ellipsoidal head t

=

PD 2SE – 0.2 P

t

=

100 x 96.25 2 x 17500 x 1 – 0.2 x 100

=

0.275” Required thickness = 0.275 inch

8.

Design thickness = 0.275 + 0.125 = 0.400 “

9.

Use nominal thickness of dished head after forming. Use 7/16 inch

thickness = 0.4375 inch

10. MAWP =

2 SET D + 0.2 t

=

2 x 17500 x 1 x 0.3125 96.25 + 0.2 x 0.3125

Here t = nominal thickness – C.A. = 0.4375 – 0.125” = 0.3125 inch

47 IET/CH/TP/002-R02, Sept.11

11.

For torispherical head

t=

0.885 PL SE – 0.1 P

t

=

0.885 x 100 x 96.125 17500 x 1 – (0.1 x 100)

=

0.486 inch

12.

Design Thickness = 0.486 + 0.125 = 0.611 inch

13.

Vessel part MAWP for shell

= 115.37 psi

Vessel part MAWP for heads

= 113.563.psi

Vessel MAWP will be lowest value of vessel part MAWP, Hence, vessel MAWP

= 113.563.psi

48 IET/CH/TP/002-R02, Sept.11

CASE STUDY – 2 (MAWP Calculations)

Q.1

A vessel is using service fluid with specific gravity = 1. What is the static head at a location 30 feet from Top of Vessel?

Q. 2

If Vessel in Q. 1 is stamped as Vessel MAWP = 120 psi. What is Total Pressure at location (a) 30 feet from top of vessel? (b) 50 feet from top of vessel (sp. qr. of fluid = 1)

Q. 3

After 20 years of service for above vessel, due to corrosion and thickness reduction, it was found that vessel part MAWP at location 30 ft from top became 125 psi and the vessel part MAWP at location 50 ft from top became 130 psi. What will be the safe vessel MAWP now?

49 IET/CH/TP/002-R02, Sept.11

SOLUTION :CASE STUDY- 2 (MAWP Calculation)

1)

Static head

=

0.433 x liquid column in feet 0.433 x 30 = 12.99 psi

2)

Total Pressure

=

Vessel MAWP + Static head

(a) For location 30 ft from top Total pressure

=

120 + 12.99

=

132.99 psi

(b) For location 30 ft from top Total pressure

3)

Vessel MAWP

=

120 + 0.433 x 50

=

120 + 21.65

=

141.65 psi.

=

Part MAWP – Static head

a) For location 30 ft from top Vessel MAWP

b)

=

125 – 0.433 x 30

=

125 –12.99

=

112.01

For location 50 ft from top,

Vessel MAWP

=

130 – 0.433 x 50

=

130 –21.65

=

108.35

Out of a) & b) above lower value will give safe Vessel MAWP = 108.35 psi.

50 IET/CH/TP/002-R02, Sept.11

CASE STUDY – 3 (Pressure Testing) Following information is taken from vessel data sheet for a new vessel. Design Pr = 130 psi. Vessel MAWP = 150 psi. Safe stress at design temperature = 18000 psi Safe stress at design temperature = 19800 psi Vessel MDMT = 10o F

Calculate the following Q.1

Hydrostatic Test Pressure

Q. 2

Hydrostatic Test temperature

Q.3

Relief value set Pressure

Q.4

For hydrostatic test Pneumatic Test Pressure

Q.5

Pneumatic Test temperature

Q.6

Inspection pressure at which leak check shall be performed for Pneumatic Test

Q.7

First stage pressure for Pneumatic Test

Q.8

What will be total pressure at the end of fourth step of Pneumatic test?

Q.9

Total 5 pressure gauges with the following ranges are available in the store 0-300 psi, 0-400 psi, 0-600 psi, 0-800 psi, 0-1000 psi We need 2 pressure gauges for Pressure test Which of the two gauges you will choose for Hydrostatic test ?

Q.10

For Pneumatic testing which of the two gauges from the given five gauges you find suitable ?

51 IET/CH/TP/002-R02, Sept.11

SOLUTION : CASE STUDY- 3 (Pressure Testing)

1)

2)

3)

4)

5)

6)

Hydrostatic Test Pr

Hydrostatic Test temp

Relief Value set Pr

Pneumatic Test Pr

=

1.3 x MAWP x 19800/18000

=

1.3 x 150 x 1.1

=

214.5 psi

=

MDMT + 30 0 F (Recommended)

=

10 + 30

=

40 0 F

=

1⅓ X Test Pr

=

1.333 x 214.5

=

286.0 psi

=

1.1 x MAWP x 19800/18000

=

1.1 x 150 x 1.1

=

181.5 psi

Pneumatic Test Temp (Mandatory)

Inspection Pressure

=

=

MDMT + 30 0 F

=

10 +30

=

40 0 F

Pneumatic Test Pr 1.1

=

181.5 1.1

=

7)

165 psi

First stage Pressure (Pneumatic) =

50% of Test Pr

=

50% of 181.5

=

90.75 psi 52

IET/CH/TP/002-R02, Sept.11

8)

9)

Pressure at end of fourth stage =

50% + 3 times10% .

=

80% of 181.5

=

145.2 psi

For Hydrotest the two gauges are to be selected

Lower limit of range = 1.5 x 214.5 = 321.75 psi Upper limit of range = 4 x 214.5 = 858 psi Preferred limit of range =

2 x 214.5 = 429 psi

We can use 3 gauges, 0-400psi, 0-600 psi and 0-800 psi But Choose the two gauges which are nearest to preferred range Choose 0-400 psi and 0- 500 psi

10)

For Pneumatic testing the two gauges from the given five Lower limit = 1.5 x 181.5 = 272.25 psi Upper limit = 4 x 181.5 = 726 psi Preferred limit of range =

2 x 181.5 = 363 psi

We can use 3 gauges, 0-300 psi, 0-400psi and 0-600 psi But Choose the two gauges which are nearest to preferred range Choose 0-300 psi and 0-400 psi

53 IET/CH/TP/002-R02, Sept.11

CASE STUDY – 4 (Assessment for Impact test)

Q.1

A vessel is to be constructed using 1.50 inch thick plates SA 516 Gr 70

normalized. Minimum design metal temperature (MDMT) is 0 0 F. Will

Not

you

require impact testing as per Fig. UCS 66 of ASME Sec VIII Div 1?

Q. 2

If the plates in Q. 1 above were normalized. Will impact testing be required if MDMT is 0 0 F?

Q. 3

If normalized SA 516 Gr 70 plates are used having thickness = 2.5 inch. MDMT is still 0 0 F. Will you require impact test?

Q.4

A vessel is to be constructed wing 1 inch thick SA 515 Gr. 70 plate material. MDMT = 60 0 F. Will you specify impact test?

Q. 5

A vessel is made from 1 inch thick plates SA 285 grade C. MDMT = 67

0

F.

Will impact Test be required?

Q.6

A vessel is made from 1 inch thick SA 515 Gr 60 (PN. 1) plates MDMT = 10 0

F. The vessel did not require PWHT as per Code but due to service

requirement, PWHT is to be performed. Is impact testing required?

Q.7

A material having minimum specified yield strength, as 42000 psi was requiring impact test. Nominal thickness of material is 1 inch during impact Test impact values reported were Specimen 1 : 18 ft 1b Specimen 2 : 17 ft 1b Specimen 3 : 13 ft 1b Is impact test acceptable?

54 IET/CH/TP/002-R02, Sept.11

SOLUTION: CASE STUDY – 4 (Assessment for Impact test)

1)

In this example Curve B will apply. Referring to Fig UCS – 66, the point is below the curve, hence Impact Testing is required.

2)

New Curve D will apply. Point lies above curve (thickness = 1.5” & MDMT = 0o F) Impact test not required.

3)

With Thickness = 2.5 inch, MDMT = 0o F & Curve is D Point lies below curve Impact test required.

4)

Curve A applies With Thickness = 1” & MDMT = 60o F Point is below curve. Impact test required.

5)

Curve A applies. Thickness = 1“ MDMT = 67 0 F The point is close to Curve decision is difficult go to table UCS - 66 For 1” thickness & Curve A, temperature on Curve is 68

0

F. Our MDMT is

less than 68 0 F impact test required.

6)

Curve B applies. Thickness = 1” Temperature on Curve is 31 0 F (transition temperature) Due to PWHT (UCS –68 C) a reduction of 30 0 F can be given Transition temperature now is 31 – 30 = 1 0 F 55

IET/CH/TP/002-R02, Sept.11

Our MDMT = 10 0 F MDMT is higher than transition temperature. No impact testing is required.

7)

Referring Fig. UG – 84.1 & Note b.

Required Average for 3 specimen = 15 ft 1b Actual average obtained

=

18 + 17 + 13 3

= 48 3

= 16 ft 1b

Average obtained, 16 ftlb > 15 ft lb NN. OK Minimum for one specimen must be >

⅔ of Average required = 10 ft/b

Actual minimum for one specimen = 13 ft/b 13 > 10 ft/b -----------------OK Both criteria of Average & minimum are satisfied – Test is accepted.

56 IET/CH/TP/002-R02, Sept.11

CASE STUDY – 5 (Nozzle Reinforcement Calculation) A vessel is provided nozzle on the cylindrical shell. Various dimension are as follows (with usual notation) Diameter of finished opening (d) = 4.2 inch, t = 0.8”, tr = 0.6”, tn = 0.7”, tnr = 0.2”. Answer questions below :

1)

What is Reinforcement limit along vessel wall?

2)

What is Reinforcement limit normal to vessel wall?

3)

What is total reinforcement area required?

4)

What is area available in shell?

5)

What is area available in nozzle?

6)

Is the nozzle adequately reinforced or will it require additional reinforcing pad?

57 IET/CH/TP/002-R02, Sept.11

SOLUTION: CASE STUDY – 5 (Nozzle reinforcement Calculations)

1)

Reinforcement limit along the vessel wall = 2d = 2 x 4.2 = 8.4”

2)

Reinforcement limit normal to vessel wall= 2.5 tn = 2.5 x 0.7 = 1.75”

3)

Total Reinforcement Area required

= dtr

= 4.2 x 0.6 = 2.52 sq. inch.

4)

5)

6)

Area available in shell

Area available in nozzle

=

d (t - tr)

=

4.2 (0.8 – 0.6)

=

4.2 x 0.2

=

0.84 sq. inch

=

5tn (tn- tnr)

=

5 x 0.7 x (0.7 – 0.2)

=

5 x 0.7 x 0.5

=

1.75 sq. inch

Total area available in shell & nozzle 0.84 + 1.75 =

2.59 inch

Since Area available (2.59 sq.in.) is greater than area required (2.52 sq.in.) Nozzle is adequately reinforced. It does not require separate reinforcement pad.

58 IET/CH/TP/002-R02, Sept.11

CASE STUDY – 6 (A) External Pressure (UG – 28) 1)

What will be allowable external pressure for the following? Is it safe for full Vacuum (15 psi)? Vessel OD = 96”

2)

Vessel thickness

=

5/8” (0.625”)

Value of Factor A

=

0.00022

Value of Factor B

=

3000

For a cylindrical shell having OD = 48”, Shell thickness

= 0.5 inch

Corrosion allowance

= Nil.

Value of factor A

= 0.00015

And value of modules of elasticity = 29 x 106 psi What is allowable external pressure?

(B) Weld size for openings (UW – 16) 1)

What will be minimum fillet weld leg dimension for reinforcement pad to shell weld in sketch a-1 in Fig. UW – 16.1 of ASME Code? Thickness of pad = 0.8 inch. Thickness of shell = 1”.

2)

What will be the size of fillet weld joining reinforcement pad to nozzle neck in sketch (h) of Fig. UW 16.1? The nozzle thickness = 0.5 inch & reinforcement pad thickness = 0.6 inch.

3) What is throat dimension (tc) required for the fillet weld joining nozzle neck to shell if shell thickness = 1.2 inch? Nozzle neck thickness = 1.0” Refer sketch d of UW – 16.1

59 IET/CH/TP/002-R02, Sept.11

SOLUTION :CASE STUDY- 6 (Miscellaneous Calculations)

(A)

Allowable external Pressure is given by 1)

Pa

=

4B 3 ( Do/ t )

Here Do = 96 inch t = Net thickness = 5 – 1 = 1 8 8 2 B = 3000

Pa

= =

4 x 3000 3 (96/0.5) 20.8 psi

20.8 > 15 Psi

2)

= 0.5”

N..

safe for full vacuum

Here value of B is not available. Allowable external pressure is given by Pa =

2AE

=

3 (Do/t)

2 x 0.0095 x 29 x 10 6 3 (48/0.5)

Allowable external pressure= 30.2 psi (Here t = 0.5”, A = 0.00015, E = 29 x 106, Do = 48”)

60 IET/CH/TP/002-R02, Sept.11

B)

1)

Refer Fig. A –1 of UW – 16.1 Fillet weld throat dimension = t min

1 t min 2 = Minimum of shell thk, pad thickness & ¾” = Minimum of 1”, 0.8”, 0.75”

t min Throat But throat

=1 2 =

= 0.75” t min = 1 x0.75 2 0.707 x leg

∴leg =

Throat = 0.707

= 0.375”

0.375 0.707

= 0.53”

Minimum leg size = 0.53”

2)

Refer Fig. h of UW – 16.1 throat dimension = 0.7 t min t min

= Minimum of 0.5”, 0.6”, 0.75”

t min

= 0.5”

Throat

= 0.7

∴leg size

=

x 0.5 Throat 0.707

= 0.35” =

0.35 0.707

= 0.495”

Minimum leg size = 0.495”

3)

Refer sketch d of UW – 16.1 min t c

= smaller of ¼ ” or 0.7 t min

but t min

= Minimum of 1.2 ”, 1”, 0.75”

smaller of ¼” or 0.7 x 0.75” = smaller of 0.25” or 0.525” Minimum throat dimension = 0.25”

61 IET/CH/TP/002-R02, Sept.11

CASE STUDY – 7 Numerical in API 510 Code

(A)

Following information is available from vessel data sheet & inspection records for a vessel in service. The service in unchanged from 2002 & will continue. Initial thickness = 1.2 inch (1992 May) First shutdown inspection thickness = 1.1 inch (1997 May) Second shutdown inspection thickness = 1.05 inch (2002 May) Current inspection thickness = 0.9 inch (2007 May) Required thickness = 0.75 inch

Calculate following : 1.

Long term corrosion rate

2.

Short term corrosion rate

3.

What corrosion rate is to be considered of for Remaining life calculation?

4.

Calculate Remaining Life.

5.

What are next maximum internal & external inspection intervals?

(B)

A fillet patch is to be installed on a vessel with vessel ID = 48 inch &vessel

thickness where the patch is to be welded is 3/8”. What should be minimum Toe to toe distance from a similarly welded existing patch?

(C)

Calculate corrosion averaging long the for locally corroded areas of considerable size for following vessels. There is no wind load & there is no nozzle in corroded area. Vessel 1, I.D = 32” Vessel 2, I.D = 48” Vessel 3, I.D = 60” Vessel 4, I.D = 90” Vessel 5, I.D = 126”

62 IET/CH/TP/002-R02, Sept.11

(D)

A vessel was constructed with 4” thick SA 516 Gr 70 material (70000 psi min. tensile strength) there was corroded area having depth = 1.8 inches. The repair was performed by weld overlay having tensile strength = 60000 psi. What shall be min. build up thickness?

(E)

Estimate the maximum permitted next internal & external inspection intervals for following 4 vessels. All vessels will be in continuous service. No RBI is performed. Vessel A, Remaining life = 24 years Vessel B, Remaining life = 16 years Vessel C, Remaining life = 8 years Vessel D, Remaining life = 3 years

(G)

A vessel was inspected for thickness measurement. Actual thickness was found to be 0.86 inch. Next thickness inspection interval is 5 years. Corrosion rate = 10 mpy. What value of thickness should be used in MAWP calculation ?

(H)

Following information is taken from vessel data sheet Design Pr = 100 psi. Vessel MAWP = 120 psi. Safe stress at design temperature = 18000 psi Safe stress at design temperature = 19800 psi Vessel MDMT = 10o F. Vessel thickness = 2 inch.

1. If the above vessel was constructed in 1992, what will be Hydrostatic test pressure if pressure test was required on it, after major repairs? 2. If the above vessel was constructed in 2002, what will be Hydrostatic test pressure if pressure test was required on it, after major repairs? 3. What will be the minimum temperature maintained during the Hydrotest ?

63 IET/CH/TP/002-R02, Sept.11

SOLUTION : CASE STUDY- 7 (Numericals in API 510 Code)

(A)

t initial

=

1.2 inch (May 1992)

t previous

=

1.05 inch (May 2002)

t actual

=

0.9 inch (May 2007)

t required

=

0.75 inch

1)

Corrosion rate (L.T.) =

t initial – t actual No. of years between t initial & t actual

=

1.2 –0.9 15

=

2)

0.020”/year = 20 mpy

Corrosion rate (S.T.) =

t previous – t actual No. of years betn t previous & t actual

=

= 3)

1.05 –0.9 5 0.030”/year

= 30 mpy

S.T. rate reflects current process used S.T. Corrosion rate (30 mpy) for remaining life calculation.

4)

Remaining life = t actual – t required/ Corrosion rate =

0.9-0.75 0.030

=

5 years

64 IET/CH/TP/002-R02, Sept.11

(5)

Next internal inspection

=

Lower of (1/2 x5) or 10 year

=

Lower of 2.5 years or 10 years

=

2.5 years

=

Lower of internal or 5 years

=

Lower of 2.5 years or 5years

=

2.5 years

4 √RT

=

4 √48/2 x 3/8

4√9

=

12 inches.

= Lower of

ID 2 32 2

or 20” (for I. D ≤ 60”)

External inspection

(B)

Spacing (d) =

d

(C)

=

Vessel 1, L

= Lower of

Vessel 2, L = Lower of = Lower of

Vessel 3, L

= Lower of =Lower of

Vessel 4, L

= Lower of =Lower of

Vessel 5, L

=Lower of =Lower of

or 20”NN

ID 2 48 2

or 20”

ID 2 60 2

or 20”

ID 3 90 3 ID 3 126 3

or 20”NN

or 20”NN.

use 16 inch.

use 20 inch.

use 20 inch.

or 40” (for ID > 60”) or 40”N N

use 30 inch.

or 40” or 40”NN.

use 40 inch.

65 IET/CH/TP/002-R02, Sept.11

(D)

Build up thickness =

Repair depth x strength of Base metal strength of weld metal

=

1.8 x 70000 60000

=

(E)

Vessel A, Internal

2.1 inch.

= Lower of ½ (Remaining life) or 10 years = Lower of ½ x 24 or 10 = 10 years.

External

= Lower of internal or 5 years = Lower of 10 years or 5 years = 5 years.

Similarly for other vessels calculation can be done Vessel B: Internal = 8 years, External = 5 years Vessel C: Internal = 4 years, External = 4 years Vessel D: Internal can be any interval maximum up to 2 years & external same as internal. (remaining life is less than 4 years).

F)

G)

Thickness (t) =

tactual – 2 (C.R x Interval)

=

0.86 – 2 (0.010 x 5)

=

0.86 –0.1 = 0.76 inch

(1). For Vessel with year of construction 1992, Hydrostatic test Pr =

1.5 x MAWP x

Sat test temp

Sat design temp 66 IET/CH/TP/002-R02, Sept.11

= 1.5 x 120 x 19800 18000

= 198 psi

2. For vessel with year of construction 2002, Hydrostatic test Pr

=

1.3 x MAWP x

Sat test temp

Sat design temp = 1.3 x 120 x 19800 18000

3)

= 171.6 psi

Test temperature = MDMT + 10 deg.F = 10 + 10 = 20 deg. F

67 IET/CH/TP/002-R02, Sept.11

API 510- INSERVICE PRESSURE VESSEL INSPECTOR PREPARATORY COURSE

PART V

WPS/POR ROAD-MAP AND REVIEW

68 IET/CH/TP/002-R02, Sept.11

Review of WPS/PQR (Road Map) Start at Front side of PQR.

Do the P, F & A Nos. match with mtl. Spec No & filler AWS No.

No

Go to back side of PQR.Are the results for tensile, and bend tests stated.

No

(QW 140)

Yes

For tensile test are qty of specimen, area and unit stress calculation right

No

(QW – 451.1)

Yes

No

Is location of failure stated

R

Yes No

Start

E

Is unit stress > (QW – 153) SMTS of base metal

Yes Was break in

Yes

weld metal Is the WPS supported by PQR. Does WPS show reference No. of the supporting PQR

No No

No

J

No

Is PQR signed and dated

No Yes

E

No

No

Is bend test Qty, type stated and correct

(QW – 451.1)

Yes

Is the result stated & OK

(QW – 163)

Yes

No

Yes Accept for detailed review

(QW – 153)

Yes

Yes

Has PQR been revised

Is unit stress > 95% of SMTS of base metal

C

Are results for toughness (QW – 172) test (if any) OK Yes

Place WPS & PQR side by side

Go to tables as follows SMAW - QW 253 SAW – QW 254

T No

Check WPS/PQR for QW 402 to QW 410 for the following WPS: EV, NEV, PQR: EV, Are the documents OK?

No

If the welder is to be qualified on the basis of PQR. Is his Identifying code. Position of welding recorded on PQR.? Yes

Accept

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Mistakes in WPS/PQR Documentation. PQR REVIEW: A. PQR/2007/011 (Front side): 1. Check P,F and A Nos…….P No. 1 is OK, F No. should be 4 instead of 2, A No. OK

B. PQR (Back Side) 1. No. of Tensile Test Specimen=2 …OK. But result of first tensile specimen(W.M.fracture)is not accepted.

Second specimen is OK

2. Bend tests specimen Nos. = 4…OK, Test results also OK, but specimen tested are wrong. They must be 4 side bends for Test coupon thickness=o.75 inch.

WPS REVIEW: C. WPS/ 2007/24(Front side) Check P.No , F No, A No. Change F No. to agree with PQR ( change F no. to 4) Base metal thickness range shall be= 3/16 inch to 1 ½ inch. Weld metal thickness range shall be = 0 to 1 ½ inch. D. WPS (Back side) Min. Preheat shall be 120 deg.F PWHT shall be Nil….since PQR is without PWHT.

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API 510- INSERVICE PRESSURE VESSEL INSPECTOR PREPARATORY COURSE

PART VI

ADDITIONAL INFORMATION REFERANCE DIAGRAMS & TABLES

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TYPICAL IMPACT TESTING APPARATUS

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API 510 PREPARATORY COURSE EXAMPLES OF REPAIRS AND ALTERATIONS

INTRODUCTION The following examples are intended to provide owners, users, repair organizations and Inspectors the assistance in evaluating whether contemplated work on a pressure retaining item should be categorized as a repair or alteration.

EXAMPLES OF REPAIRS Examples of repairs are. 1. Weld

repairs

or

replacement

of

pressure

parts

or

attachments that have failed in a weld or in the base material: 2. Corrosion resistance strip lining or weld overlay: 3. Weld buildup of wasted areas; 4. The addition of welded attachments to pressure parts, such as; a. studs for insulation or refractory lining b. ladder clips c. brackets, having loading which do not affect the design of the pressure retaining item to which they are attached d. tray support rings 5. Replacement of heat exchanger tube sheets in accordance with the original design: 6. Replacement of boiler and heat exchanger tubes where welding is involved. 89 IET/CH/TP/002-R2, Sept. 11

7. The installation of a flush patch to a pressure retaining item. 8. Replacement of pressure parts identical to those existing on the pressure retaining item , such as, a. Replacement of a shell or head in accordance with the original design. b. Re-welding a circumferential or longitudinal seam in a shell or head c. Replacement

of

nozzles

of

a

size

where

reinforcement is not a consideration 9. Installation of new nozzles or openings of such a size that reinforcement is not a consideration. For example the installation of a 3 NPS nozzle to a shell or head of 3/8 in. or less in thickness or the addition of a 2 NPS nozzle to a shell of head of any thickness. 10.

The addition of a nozzle where reinforcement is a consideration may be considered to be a repair if

the

nozzle is identical to one in the original design, located in a similar part of the vessel, 11.

The replacement of a shell course in a cylindrical pressure vessel.

12.

Welding of wasted or distorted flange faces.

13.

Replacement of slip-on flanges with weld neck flanges or vice-versa.

14.

Seal welding of butt straps and rivets;

15.

The repair or replacement of a pressure part with a Code accepted material that has a normal composition and strength that is equivalent to the original material.

16.

Replacement of a pressure retaining part with material of different nominal composition, equal to or greater in allowable stress from that used in the original design, provided the replacement material satisfies the material

90 IET/CH/TP/002-R2, Sept. 11

and

design

requirements

of

the

original

code

of

construction under which the vessel was built.

EXAMPLES OF ALTERATIONS 1. An increase in the maximum allowable working pressure (internal or external) or temperature of a pressure retaining item regardless of whether or not a physical change was made to the pressure retaining item. 2. A decrease in the minimum temperature such that additional mechanical tests are required or at least design check is needed to confirm the suitability. 3. The addition of new nozzles or opening (in a boiler or pressure vessel) of new sizes other than existing sizes and requiring new reinforcement calculations. 4. A change in the dimensions or contour of a pressure retaining item. 5. The addition of pressurized jacket to a pressure vessel. 6. Except as permitted in Repair, replacement of a pressure retaining part in a pressure retaining item with a material of different allowable stress or nominal composition from that used in the pressure retaining item to which it is attached. 7. The addition of a bracket or an increase in loading on an existing bracket which affects the design of the pressure retaining item to which it is attached.

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API 510 Preparatory Course

WELCOME QUIZ Note: Choose only one option which you think is most appropriate. 1.

Which of the following types of discontinuities is not normally detected by radiography? a. b. c. d.

2.

Cracks Incomplete penetration Laminations Slag

API 510 __________ be used as a substitute for the original construction of pressure vessels before it is placed in-service. a) b) c) d)

3.

Identify incorrect statement from following, if any. a. b. c. d.

4.

A welder performing procedure test is also qualified in that position. Supplementary essential variables become essential variables when impact test is specified. For procedure qualification, the test can be performed in any position as the position is not essential variable for procedure qualification. None of above is incorrect statement

In plate specification A 516 Gr 70, the letter A indicates: a. b. c. d.

5.

Shall not Should May Shall

That material is ASME material. (A for ASME) That material is Ferrous material That material is Non-Ferrous material None of the above

The symbol which indicates ASME code stamping for vessels manufactured to ASME Section VIII Div. 1 is a) b) c) d)

U1 U2 U None of these 92

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6.

A restoration work by weld-overlay was carried out on corroded wall of vessel and it can now be used as per the design conditions of the vessel. This activity will be termed as: a. b. c. d.

7.

In certain MP. Check of pr. Vessel, The size of "indication" for a certain discontinuity was seen as 4 mm but after the MP. Check and using magnifying glass it was seen having actual size as 2.5mm only. If stipulated acceptance criteria for that type of discontinuity was 3 mm, your decision is: a. b. c. d.

8.

2 3 4 None of these

A stainless steel weld has a crack open to the surface . Which NDT method will reveal it effectively? a. b. c. d.

10.

The size of indication is higher than 3mm. Reject. The size of discontinuity is lower than 3 mm, Accept. Depends on opinion of Examiner. Depends on the procedure adopted for MPI, i.e dry or wet particles.

ASME Code requires averaging of impact test values of how many specimen for the relevant acceptance criteria. (a) (b) (c) (d)

9.

Renewal of vessel Repair of vessel Alteration to vessel Re-rating of vessel

Liquid Penetrant Magnetic particle Radiography All of above.

PQR document normally may be revised and re submitted for acceptance. a. b. c. d.

True False Depends on company policy Depends on Third party inspector’s discretion.

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11.

Hot tapping is best described by statement: a. It is technique of preheating the vessel wall to specified temperature and tapping with 1lb. rounded hammer to detect wall thinning b. It is technique of providing a tapping connection while the system is in operation c. It is technique of fixing a on/off tap on drain nozzle of pressure vessel d. It is act of pre heating the component before using the tap and die for threading so that less effort is required for threading operation.

12.

Which of the following represent grouping of weld-metals in ASME IX? a. b. c. d.

13.

A inspector should be stricter while carrying out inspection on: a. b. c. d.

14.

Longitudinal Joint Circumferential Joints Both are equally critical as per ASME Sec. VIII, Div.1 Depends on QA plan

PT examination is used to detect the surface cracks in welds as well as in base metal plates. For proper detection, a. b. c. d.

15.

P – Nos F – Nos S – Nos A - Nos

We should allow higher penetrant time on weld We should allow higher penetrant time on plates Penetrant time on weld as well as plates is same Depends on type of penetrant used.

As per ASME Sec. VIII Div. 1, “Weld joint category” means: a. b. c. d.

Type of weld, i.e., Single V type, Double V type, U type etc. Type of weld, i.e., Full penetration, partial penetration etc. Location of weld, i.e., longitudinal, circumferential, nozzle attachment weld etc. Type of weld joint, i.e., Butt-weld joint, fillet weld joint, lap joint, etc.

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API 510 Preparatory Course

WELCOME QUIZ Answer Key Q. NO. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

ANSWER C A D B C B A B A B B D A B C

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API 510 Preparatory Course PACTICE QUIZ - 1 (Closed Book) Note: Choose only one option which you think is most appropriate. 1.

In a 30 mm thick cylindrical shell, the longitudinal as well as circumferential joints are double welded butt welds with full penetration. Which of the following is true as regards the longitudinal and circumferential joints? a. b. c. d.

2.

Thickness calculated for Internal pressure only is known as: a. b. c. d.

3.

Design Thickness. Nominal thickness Actual thickness Required thickness

A Shell with Inside dia = 2200 mm, and Corr. allow.= 5 mm is to be designed as per ASME Sec. VIII , Div.1. What will the value of “R” in design formula for shell thickness? a. b. c. d.

4.

They are of same category but different types. They are of same type but different categories. Both the category as well as type are same. Both the category as well as type are different.

1100 mm 1105 mm 1095 mm 1110 mm

In thickness formula for internal pressure for shell, term ‘E’ refers to: a. b. c. d.

Modules of Elasticity of material Thermal Expansion Joint efficiency of the weld None of above

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5.

The hydrostatic pressure caused by 10 ft. of liquid column (sp. gr. = 1) will be: a. b. c. d.

6.

10 psi 43.3 psi 4.33 psi None of the above

A new pressure vessel should be inspected to which of the following codes? a. b. c. d.

API 510 , ASME Sec. 1, ASME Sec. VIII Div. 1, None of these

Code rules for testing vessels in service are detailed in: a. b. c. d. 8.

API 510 API 570 ASME Section VIII Div.1 None of above

Identify category A joints from following: a. b. c. d.

Longitudinal joints Circumferential joints, shell to shell Shell to hemispherical head joint a and c above

9. If all other conditions are remains same the design thickness of which dished end (Torispherical, Hemispherical, Ellipsoidal) will be maximum? a. b. c. d. 10.

Torispherical Hemispherical Ellipsoidal All will be same

Any thickness-offset within the allowable tolerance shell be provided a minimum taper transition of: a. b. c. d.

1 to 3 min 1 to 1 min 1 to 2 min 1 to 4 min

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11.

Thickness for Internal pressure plus the corrosion allowance is known as: a. b. c. d.

12.

Nominal Thickness. Design thickness Actual thickness Required thickness

Vessel MAWP for vertical vessel is measured at: a. b. c. d.

Top most point of vessel Bottom most point of vessel At the mid point between top & bottom None of above

13. Which of the following statements is true? a. b. c. d.

14.

A Pressure Vessel is designed for 0.85 joint efficiency with full penetration welds. RT requirement will be: a. b. c. d.

15.

Nil Spot 100 % T-joints radiography

A vessel with 50 inches OD and 1¼ in. thickness is to be provided Std. torisph. heads. The heads shall be formed with crown radius and min. knuckle radius as follows: a. b. c. d.

16.

All defects are not discontinuities. All discontinuities are defects. Discontinuities are rejectable defects. Defects are rejectable discontinuities.

25 inch, 50 inch, 50 inch, 25 inch,

4 inch 3 inch 3¾ inch 2 inch

If there is a conflict between ASME VIII & API 510 Code, for vessels inservice: a. b. c. d.

ASME will precedent API will precedent ASNT will precedent Owner user will decide

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17. Two head to shell joints, one joining a seamless Hemisph, head to shell was radiographed for full length and the other joint joining seamless std. torisph. head to shell was spot radiographed, The weld joint efficiency for each of these heads respectively will be: a. b. c. d. 18.

1, 0.85 1, 1 0.85, 1 0.85, 0.85

ASME Sec. VIII Div. 1 recommends use of U.T. in place of R.T. (for a fully radiographed vessel) for: a. b. c. d.

All butt welds in vessel All butt and fillet welds in vessel For closing seams only The code does not permit use of U.T. at all

19. The commercially available thickness used for vessel fabrication is known as: a. b. c. d. 20.

Nominal Thickness. Design thickness Actual thickness Required thickness

For a vessel constructed with Type 1 welds: a. b. c. d.

RT3 means E = 1 RT2 means E = 0.85 RT1 and RT2 may mean E = 1 RT4 means spot radiography

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API 510 Preparatory Course PACTICE QUIZ - 1 (Closed Book) ANSWER KEY Q. NO. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

ANSWER B D B C C C A D A A B A D B C B B C A C

REFERENCE ASME VIII, UW – 3 (a) ASME VIII, App. 3 . Definitions ASME VIII, UG – 27 (a), UG -16 (e) ASME VIII, UG – 27 (a) Body of Knowledge, 3 (a), Page 2 API 510, 1.1.1 API 510, 1.1 ASME VIII, UW – 3 (a) (1) ASME VIII, UG – 32, d, e, f ASME VIII, Fig. UW - 9 ASME VIII, App. 3 . Definitions ASME VIII, UG – 98 (a) General Knowledge ASME VIII, Table UW - 12 ASME VIII, UG – 32 (j) API 510, 1.1.1 ASME VIII, UW – 12 (d) ASME VIII, UW – 11 (a) - 7 ASME VIII, App. 3 . Definitions ASME VIII, UG – 116 (e)

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DAILY POINTS TO RECALL (Day 1) 1.

ASME codes edition is issued once in 3 years and addenda, once a year – both on 1 July. Edition and addenda become effective on 1st January of next year (i.e., 6 months after issue).

2.

ASME Sec VIII Div.1 is Unfired Pressure Vessel and is applicable to pressures exceeding 15 psig, and diameters above 6.0”. Pump and turbine casings are excluded from scope.

3.

Thickness of cylindrical shell

t =

__PR__

+ C

SE – 0.6P

4.

Longitudinal weld is more critical because it is subjected to double the stress than Circ. Weld.

5.

‘Weld joint categories’ A, B, C, D – are based on joint locations in the vessel and stress levels encountered weld Types’ (type 1, 2, 3 … etc.) describe the weld itself.

6.

Depths of 2:1 Ellip and hemisph. Heads are D/4 and D/2 respectively. (D= Head diameter.)

7.

Weld Joint categories: Category A: - All longitudinal welds in shell and nozzles. - All welds in heads, Hemisph-head to shell weld Category B: nozzles,

-

All circumferential welds in shell and

- Head to shell joint (other than Hemisph.)

Category C and D are flange welds and nozzle attachment welds respectively.

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8.

Weld Types: Type 1: Full penetration welds (Typically Double welded) Type 2: Welds with backing strip. Type 3: Single welded partial penetration welds. Type 4, 5, 6 are various Lap welds (rarely used)

9.

For full penetration welds (type 1), Joint efficiency,

E=

For the radiography = 10.

100%, 85%, 70%, Full, Spot, Nil respectively.

Radiography marking on name plates (typically for Type-1 welds)

RT-1: (E=1)

All butt welds – full length radiography.

RT-2: (E=1.0)

All Cat. A

Butt welds Full length, Cat B,

spot RT-3: (E=0.85) Spot radiography of both Cat A and B welds RT-4: (E=0.7) Partial / No radiography 11.

For seamless heads, E=1, If head to shell weld is fully radiographed (if Cat. A), and at least spot radio graphed (if Cat. B)

12.

For Welded Heads for E=1, all welds within the head require full length radiography (since they are all Cat A welds) and head to shell weld is fully radiographed (if Cat A), or at least spot radiographed (if Cat. B)

13. Compared to Cylindrical shell, thickness of 2:1 Ellipsoidal head is approx. same as shell, Hemisph. head approx. half and Torisph head is 77% higher. 14.

MAWP is calculated for: Working condition (Hot & Corroded). Vessel MAWP is always taken at the top of the Vessel and is lowest of all part MAWPs adjusted for static pressure.

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DAILY EXAM 2 (Open) Note: Encircle the letter of only one answer which you think is most appropriate.

1.

A standard seamless, ASME F & D head (Torispherical) is used for the following conditions: Material of Construction Design Pressure Design temp Inside Crown Radius Minimum available thk.

= =

SA 515 gr 60 = 250 psig 580ºF = 72 inches = 1.14 inches

Category B welds are spot radiographed. Corrosion allowance = 0.125 inches Allowable stress at design temp. = 16400 psig Your assessment is: a. The head does not meet code requirements. b. The head meets the code requirements. c. Suitability would depend on decision of Pressure Vessel inspector. d. Data are not adequate.

2.

A pressure vessel is to be constructed with MDMT = +20°F, M.O.C = SA 515 gr 60 . Impact testing not performed. Required shell thickness = ¾ , dished head thk. = 1-⅛ " ( torisph. head). Determine if this material is suitable for: a. b. c. d.

3.

Both shell as well as dished head Suitable for head but not for shell Suitable for shell only but not for head Not suitable for either

For a certain pressure vessel with spot radiography, and all Welds type 1, Vessel diameter = 72 inch I.D. M.O. C = SA 515 gr 70 Design temp. = 600°F Allowable stress at design temp. = 20,000 psi If shell thk. = 5/8" and C. A = 1/8", the MAWP for the shell will be: a. b. c. d.

234 psi 168 psi 256 psi None of the above

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4.

A pressure vessel (M.O.C. 516 gr. 70) has external jacket spread over 72 inches length of the shell. (Jacket pressure = 180 psi, Jacket temperature = 350°F) the vessel OD = 36 inches. Shell thickness= 0.5 inch, C.A. = Nil. Decide which of the following are applicable in the present case. a. b. c. d.

5.

Shell thickness is OK. Shell thickness is NOT OK. Data are not adequate. Acceptance of shell thickness depends on opinion of vessel engineer.

Choose correct hydrostatic test pressure from given options for a vessel with the following data: Design Pr Design temp = M.O.C = Allow stress (Ambient) Allow stress (675°F) a. b. c. d.

6.

= 360 psi 675ºF SA 537 Cl. 1 = 18600 psi = 16900 psi

540 psig 515 psig 450 psig None of above

Impact test requirement for the two plates is to be assessed for MDMT = 0ºF, to be used for Vessel which will be hydrotested and used for steady operation. Plate A. Plate B.

Plates 537 class 1, Plates 515 gr 60,

2.0 inch thick 0.75 inch thick

Your assessment is: a. b. c. d. 7.

For vessel shell, thk= 4.0 inch, max. weld mismatch shall be as follows: a. b. c. d.

8.

Plate (A) and plate (B) both require impact test. Only (A) requires, (B) is exempt. Only (B) requires, (A) is exempt. Both do not require impact testing.

Long Long Long Long

seam seam seam seam

= = = =

¼”, circ seam = ½” ¼”, circ seam = 7/32” 7/32”, circ seam = ¼” 5/8”, circ seam = ½”

Toughness (opposite of brittleness) will be best for which materials: a. b.

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c. d. 9.

In a pressure vessel one of the 2:1 ellipsoidal dished head is removed and a new seamless dished head of same type is installed with a single ‘V’ joint with backing strip and full radiography. What is the joint category, type and efficiency of the joint now? a. b. c. d.

10.

Materials represented by curve C Materials represented by curve D

Category-B, Category-B, Category-A, Category-B,

Type-1 Type-2 Type-2 Type-2

& & & &

E-0.9 E-0.9 E-1.0 E-1.0

A pressure vessel of overall height 80’ has its part MAWP at various parts as detailed in the sketch. What is the vessel MAWP (hydrostatic head 1’ = 0.433 psi)? a. b. c. d.

419 420 430 426

psi psi psi psi

4'

426 psi 32'

54'

80'

440 psi

442.5 psi

454.64 psi

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DAILY EXAM 2 (Open) SOLUTION Q.1

Ref.: ASME VIII, UG – 32 (e), T=

E=

=

0.885 PL +C SE − 0.1P 1, (As head is seamless and Category B welds are spot radiographed.)

0.885 x 250 x 72.125 + 0.125 16,400 x 1 − 0.1 x 250

=

15957.6 + 0.125 16,375

=

0.974” + 0.125

=

1.0995” Available thickness = 1.14” ——— OK

CORRECT ANSWER: Q.2

b

Refer Fig. UCS – 66 from ASME VIII Div.1 Material is represented by curve B MDMT – Thickness point for ¾” thickness is above the curve MDMT - Thickness point 1-1/8” is below the curve Material OK for ¾” thickness — Shell Material NOT OK for 1-1/8” thickness — Head CORRECT ANSWER: c

Q.3

Ref.: UG – 27 c (1) MAWP =

SEt R + 0.6t

E = 0.85 from Table UW – 12

And t = 5/8” – 1/8” = ½” after deducting corrosion allowance MAWP =

20,000 x 0.85 x 0.5 36.125 + 0.6 x 0.5

Note: R in corroded condition =

36.125” = 233.36 . . . . say 234 psi CORRECT ANSWER: a 106

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Q.4

L/Do

= 72 / 36 = 2.0

and

Do / t = 36 / 0.5 = 72

From Fig. G of ASME II – Part D, A = 0.0011 From Fig. CS-2, B = 11500 Allowable Ext. Pr.=

4 x 11500 4B = = 212.9 psi > 180 psi . . . 3( Do / t ) 3 x 72

OK CORRECT ANSWER: a

Q.5

Refer UG – 99 of ASME VIII Hydrostatic test pressure =

1.3 x design pressure x stress ratio

=

1.3 x 360 x

=

515.0 psi

18600 16900

CORRECT ANSWER: b Q.6

Plates 537 clause 1 is curve D and 515 gr60 is curve B. From Fig. UCS – 66, plate A, the point is above curve. So impact testing not required for plate A.

For plate B, point is below the curve. Now go to UG – 20 (f). Material is P No. 1 and < 1”, and temperature > -20°F. So impact testing for B is also not required. CORRECT ANSWER: d Q.7 Refer UW – 33 Table from ASME VIII For 4” thk for long seam — 1/16” x 4 = ¼” or 3/8”, use lower value. So for long seam, mismatch = ¼” For circ seam 1/8” x 4” or ¾”, use lower value. So for circ seam, mismatch = 1/2” CORRECT ANSWER: a Q.8

Refer Fig. UCS – 66 of ASME VIII Curve D is representing the materials which are not becoming brittle when other materials (curve A, B, C) become brittle. CORRECT ANSWER: d

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Q.9

Refer Table UW – 12 of ASME VIII — This joint is type 2. — This joint is category B (Ref. UW – 3 of ASME VIII). Since the joint is between 2:1 ellip. head and the shell. — Refer (Table UW – 12 of ASME VIII), the head is seamless and joint is full radiographed. Hence, E=0.9. CORRECT ANSWER: b

Q.10 Vessel MAWP = Vessel Part MAWP — Static Head Vessel MAWP will be worked out considering Part MAWPs. For For For For

location location location location

at at at at

4 feet from top = 426 – 0.433 x 4 = 424.268 psi 32 feet from top = 440 – 32 x 0.433 = 426.144 psi 54 feet from top = 442.5 – 54 x 0.433 = 419.118 psi 80 feet from top = 454.64 – 80 x 0.433 = 420.0 psi

Vessel MAWP is lowest of all part MAWPs adjusted for hydrostatic head. Therefore, lowest value 419.118 psi is vessel MAWP. CORRECT ANSWER: a

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DAILY POINTS TO RECALL (DAY 2) 1. Hydro-Test is Standard Pressure test on Completed Vessels. Hyd. Test Pr. = 1.3 x MAWP x stress ratio Min. Insp. Pressure (hydro) = test pr. / 1.3 Min. Test temp. = MDMT + 30°F (recommended) Max. Inspection temp. = 120 deg. F 2. Pneumatic test is performed if Hydro is not possible due to design or process reasons. Prior to the test, NDT as per UW-50 is mandatory. Pneumatic Test pr = 1.1 x MAWP x Stress ratio, Pressure should be increased in steps (Total 6). 1st step – 50% of Test pressure 2nd to 6 step – 10% of Test Pr. Insp. Pr. (pneumatic) = Test pr. /1.1

3. Pressure Gauge range should be about twice the Test Pressure, However, in any case it shall not be lower than 1.5 times and not higher than 4 times the Test Pressure. 4. Vessel MAWP represents the Maximum Safe Pressure holding capacity of the vessel. Vessel MAWP is measured at top-most point. And is lowest of vessel part MAWPs adjusted for static pressure of liquid. 5. For vertical vessels, Hydrostatic pressure due to liquid with specific gravity =1 1 ft of height = 0.433 psig. 6. Total pressure at any point of Vertical vessel is given by: Total Pr. = Vessel MAWP + h x 0.433. (h = height from top in ft.) 7. If part MAWP and elevations are known, Vessel MAWP can be calculated by the deducting hydrostatic pressure from part MAWP. 8. External Pressure analysis is required when vessels are operating under vacuum or they jacketed type. 9. Ext. pressure is worked out on basis of Geometric factor A (which depends on L/Do and Do/t ratios) and factor B ( depends on A, ) Allowable Ext. Pressure,

Pa

=

4B 3(Do / t )

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10.

For values of A falling to left of material line in the material

chart, Pa 11.

=

2 AE 3( Do / t )

Name plate shows The Code stamping, MAWP, design temp., MDMT, and Extent of Radiography.

12.

For the impact test requirement, use UCS 66 curve. If MDMTthickness combination falls on or above the curve, impact testing is exempted. Additional Exemptions are given as per UG-20(f) and UCS 68 (c).

13.

ASME materials (SA) shall be used for code stamped vessel fabrication instead of ASTM (A) materials.

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DAILY EXAM 3 (Closed) Note: Encircle the letter of only one answer which you think is most appropriate.

1.

Choose correct Pneumatic test pressure for following vessel

Design Pressure Design temp. Allow stress (Ambient) Allow stress (675ºF)

= = = =

160 psi 675 ºF 20,000 psi 19,200 psi

a. 176.0 psig b. 215.6 psig c. 183.3 psig d. None of above 3.

Part MAWP for lower dished head in vertical vessel will generally be: a. b. c. d.

4.

Choose correct statement. Allowable external pressure for a vessel: a. b. c. d.

4.

Will depend on Joint efficiency (E) and extent of radiography Depends on vessel temperature Is affected by internal corrosion allowance Both b and c

The rules for impact testing of carbon steel in Section VIII vessel materials require what kind(s) of impact test. a. b. c. d.

5.

Lower than top head Lower than shell Higher than both shell and top head Same as both top head and shell

Brinell & Rockwell Izod & Charpy V-notch Charpy V-notch only is acceptable Brinell only is acceptable

Prior to witnessing a pneumatic test of a pressure vessel, the inspector should: a. b. c. d.

Ensure that welds around nozzles were inspected by PT or MT prior to commencement of test Ensure that test pressure is maintained throughout the leak testing inspection Ensure that all butt welds were UT checked prior to commencement of test Both a and b

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6.

Vessel MAWP is 200 psi. What will be the total pressure at a point 20 feet from top, if vessel is completely filled with liquid (specific gravity = 1). a. b. c. d.

7.

d.

At the option of vessel manufacturer At the option of vessel inspector Permitted only if water is not available in the region and Client approves Permitted only if design or operating conditions do not permit use of water as test medium.

What will be the minimum inspection pressure if pneumatic testing was carried out at 220 psig, as per code? a. b. c. d.

9.

psi psi psi psi

Hydrostatic pressure test of vessels may be replaced by pneumatic test: a. b. c.

8.

220.00 208.66 204.33 191.34

220 250 200 260

psi psi psi psi

For external pressure calculations, the value of “E” is worked out on the basis of:

a. E = 1 for full radiography b. E = 0.85 for spot radiography c. E = 0.7 for no radiography d. E is modulus of elasticity and does not depend on radiography In external pressure calculations for cylindrical shell, the Factor – A, depends on: a. b. c. d. 11.

O.D. and thickness of shell Design temperature Safe stress value ‘S’ of material All of the above

The size of a properly deposited equal fillet weld is shown as 10 mm. The throat dimension for this weld will be approximately: a. b. c. d.

10 mm 8 mm 7 mm 9 mm

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12.

ASME Sec. VIII, Div. 1 permits which of the following nozzle constructions? a. b. c. d.

13.

Ovality tolerance of a vessel shell with internal pressure is: a. b. c. d.

14.

Plastic formation and fracture Brittle failure Energy observed at the notch toughness

9.0 sq. inches 8.0 sq. inches 1 inch thickness 10 sq. inches

The material not requiring PWHT by code requirement has been heat-treated. The PWHT carried out on this material is most likely due to: a. b. c. d.

17.

for shell I.D. for shell O.D. of Inside radius of shell of Outside radius of shell

Reinforcement area required for an opening of diameter of 8” inside diameter and minimum required shell wall thickness 1.0” will be: a. b. c. d.

16.

1% 1% 1% 1%

The notch test is better described as: a. b. c. d.

15.

“Set-in” type “Set-on” type Both (a) and (b) None of (a) or (b)

Due to process requirement Because of the material As per authorized inspector requirement Because of welding process.

Vessel MAWP of existing vertical vessel will be affected for which of the following? e. f. g. h.

If Vessel Part MAWP changes for any vessel part. If design pressure is reduced (other factors remaining same) Vessel height is changed by adding/deleting a shell course a and c

18.Evaluation of radiographs for “Porosity” shall be carried out for Pressure vessels subjected to a. b.

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c. d. 19.

The radiographs and radiography reports of a vessel shall be maintained till: a. b. c. d.

20.

For both a and b For none of a or b

5 years Till the MDR is signed 3 years 10 years

Pneumatic test should be carried out on a vessel at 300 psig. The design temperature and the test temperature are same. What is the test pressure and in how many steps the pressure should be applied. a. b. c. d.

350 330 350 330

psig, psig, psig, psig,

6 6 2 2

steps steps steps steps

DAILY EXAM 3 (closed) ANSWER KEY Q. NO.

ANSWER

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

C C D C A B D C D A C C A D B A D A B B

REFERENCE

ASME VIII, UG – 100 (b) Body of Knowledge, 3 (d), page 2 ASME VIII, UW – II (c) ASME VIII, UG - 84 ASME VIII, UG - 100 Body of Knowledge, 3 (d), page 2 ASME VIII, UG – 100 (a) ASME VIII, UG – 100 (d) ASME VIII, UG – 28, Step 7 ASME VIII, UG – 28, Steps 2 and 3 Body of Knowledge ASME VIII, UW – 16, Fig. UW 16.1 ASME VIII, UG – 80 (a) General Knowledge ASME VIII, UG - 37 General Knowledge ASME VIII, UG 98 (a) ASME VIII, UW-52. ASME VIII, UW – 51 c (1) ASME VIII, UG – 100 (d)

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DAILY POINTS TO RECALL (DAY 3) 1.

Reinforcement pad is not required, if the size of finished opening is — Not exceeding 2 3/8“ for all thicknesses of vessel — Not exceeding 3 1/2“, if vessel thickness is < 3/8’’

2.

Reinforcement pad with OD = 2d and thk = vessel thk is always safe (d= dia of finished opening)

3.

Reinforcement Limit along vessel wall = 2d

4.

Reinf. Limit normal to vessel wall = smaller of: 2.5 t or 2.5 tn

5.

In reinforcement pad calculations, credit can be taken for area available in shell and nozzle.

6.

Fillet weld Throat dimension = 0.707 x leg of weld

7.

Adequacy of weld sizes shall be checked as required by UW-16. The nozzles construction shall be one of the Code acceptable types.

8.

The maximum permitted ovality tolerance (D max – D min) shall not exceed 1% of nominal diameter of vessel. If there is opening, then the tolerance can be increased by 2% x d (d = diameter of opening) if measurement is taken within a distance of ‘d’ from axis of opening.

9.

The mis-match tolerances and the maximum allowable weld reinforcement is more strict on longitudinal welds compared to circumferential welds (UW-35).

10. Principle of reinforcement: Area removed = Area compensated. Compensation area shall be within reinforcement limits. 11. For use as pressure parts, the plates shall be fully identified. Maximum permitted under tolerance on plates is 0.01” (0.3 mm) or 6% of ordered thickness, whichever is less. 12. All Welding (including welding of pr. parts to load carrying non-pr. parts) shall be done using Qualified procedures and welders

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13. Mandatory Full Radiography is required for all welding with thickness exceeding Table UCS-57, and also for lethal service vessels and Unfired boilers with Design Pr. More than 50 psig. 14. PWHT is Code Requirement if thickness exceeds those given in tables UCS-56 (given in notes under the tables). These tables also give min. PWHT temperature and min. holding time (soaking period) based on P-nos. and thickness respectively. 15. For Furnace PWHT, Loading Temperature shall not exceed 800 deg. F, Max. heating rate 400 deg F/hr/inch of thickness, Max. cooling rate 500 deg. F /hr/inch of thickness. Still air cooling permitted below 800 deg. F. During Soaking period, the temperature difference between hottest and coldest part shall not exceed 150 deg. F. 16. Min. Overlap for PWHT in multiple heats = 5 ft.

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DAILY EXAM 4 (Open) 1.

You are planning for the Hydro-test of a vessel with test pressure 40Kg/cm2g. The calibrated test gauges available are: 0-50 Kg/cm2g, 0-100 Kg/cm2g, 0-150 Kg/cm2g and 0-200 Kg/cm2g. Which two gauges are acceptable for this test? a. b. c. d.

2.

PWHT is required for vessels, constructed with material classified as P No. 3, Group 3 for a thickness exceeding: a. b. c. d.

3.

1100°F, 1100°F, 1250°F, 1250°F,

Time Time Time Time

= = = =

2hr., 15 min. 3hr. 3hr. 2hr., 15 min.

920 mm sq. 870 mm sq. 1020 mm sq. 1050 mm sq.

The length of a charpy specimen is: a. b. c. d.

6.

Temp= Temp= Temp= Temp=

For the given configuration, total reinforcement area to be compensated will be________. Data with usual notation: d = 100 mm, t = 12 mm, tn = 6 mm. , tr = 10.5 mm, trn = 5 mm a. b. c. d.

5.

1.0 inch 5/8 inch 0.0 inch 1.5 inch

Min. PWHT temperature and soaking period of weld with P4 and P5A, materials both with thickness = 3.0”, would be as follows: a. b. c. d.

4.

0-50 Kg/cm2g and 0-100 Kg/cm2g 0-100 Kg/cm2g and 0-200 Kg/cm2g 0-50 Kg/cm2g and 0-200 Kg/cm2g 0-100 Kg/cm2g and 0-150 Kg/cm2g

2.165” (55.0mm) 2.10” (54.0 mm) 2.15” (54.6 mm) 2.00” (50.8mm)

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IET/CH/TP/002-R2, Sept. 11

a. b. c. d. 7.

Which standard is applicable for selecting Sulphide stress cracking resistant materials for oilfield equipment? a. b. c. d.

8.

ASTM A516 ASME Sec. II NACE MR- 0103 ASME Sec. VIII

A pressure vessel is scheduled for pneumatic testing using the methodology of ASME Code, Section VIII, Division 1, with the maximum allowable working pressure = 635 psig at 375° F. The vessel is neither enameled nor lined. How many pressurization steps are needed to achieve the minimum required test pressure, and at what pressure will the visual examination be performed? a. b. c. d.

9.

0.01” or 6% (whichever is greater) 0.1” or 6% (whichever is smaller) Under tolerance for the plates is always zero 0.01” or 6% (whichever is smaller)

6 6 9 9

steps; steps; steps; steps;

635 psig 793.75 psig 635 psig 793.75 psig

For given configuration, minimum weld size (x)for the pad to shell fillet weld, ( pad thk. = 20 mm and shell thk. = 24 mm) shall be: a. b. c. d.

18 16 14 12

mm mm mm mm

(x)

10.Which of the following are excluded from the scope of application of API 510? a. Pressure vessels on movable structures covered by other jurisdictional regulations b. All classes of containers listed for exemption from construction in ASME Section VIII, Div. 1 c. Pressure vessels which do not exceed volume of the five cubic feet and pressure of 250 psi d. All of the above

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DAILY EXAM 4 (Open) Answer Key

Q. No. 1 2 3 4 5 6 7 8 9 10

Answer D C C D A D C A C D

Reference ASME VIII, UG – 102 ASME VIII, Table UCS – 56 for PNo. 3, Note 2. ASME VIII, UCS – 56 (c) ASME VIII, UG – 37, Fig. UG – 37.1, See A ASME VIII, Fig. UG - 84 ASME VIII, UG – 16 (c) API 510, Section 2 ASME VIII, UG - 100 ASME VIII, UW – 16, typ. pad to shell. (1/2 tmin) API 510, 1.2.2

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POINTS TO RECALL – DAY 4 1.

API 510 is applicable to vessels that have been placed in service, and it cannot be adopted for new constructions.

2.

Following are excluded from scope of API 510: a. b. c.

All mobile vessels All exclusions of ASME Sec VIII, Div. 1 Vessels not exceeding 5 cubic feet and 250 psi design pressure or 1.5 cubic feet and 600 psi design pressure

3.

Alteration: It is change in component that has design implications affecting pressure and/or temperature rating.

4.

Repair: It is restoring vessel suitable for operations at the present design conditions. Repairs do not change PrTemp rating of vessel.

5.

Authorized inspection agency. Any one of following: a. b. c. d.

6.

Jurisdiction organization Insurance company which under writes insurance of pressure vessels Inspection organization of owner-user Inspection organization under contract with owner user

Repair Organization: Any one of following: a. b. c. d.

Holder of ASME certificate & appropriate code symbol stamp Owner-user Contractor under contract with owner-user Organization authorized by jurisdiction

7.

On-stream inspection means NDT inspection done on Vessel without entering inside vessel. This inspection is basically to know process side deterioration.

8.

Re-rating: A change in either MAWP or temperature rating or change in both. Owner-User bears Ultimate responsibility for all activities (inspection, Engineering, repairs etc.) under API 510.

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9. Authorized Inspector is responsible to Owner-User to: a.

b. c.

Determine that all work (inspection, repairs ,alteration) is carried out as per requirements of API510 By getting involved in the actual activities performed Evaluate & accept/reject results of NDT and other tests.

10.

Repair Organization is responsible to Owner-User for the use of proper materials, Quality Control, Workmanship during the repair work performed by them.

11.

Prior to any inspection, safety rules (OSHA or other) shall be reviewed and followed. NDT equipment shall be as per Safety rules and Protective clothing shall be used where required.

12.

Modes of failure: a.

Chemical corrosion due to contaminants in fluid handled.

b.

Fatigue: Due to stress reversals (vibration, changes of temperature or pressure)

c.

Creep: At elevated temp (in areas of stress concentration)

d.

Freeze Damage: Failure due to freezing and expansion of water/aqueous solutions.

e.

Brittle failure: Due to loss of impact strength at lower temperature

f.

Tamper Embrittlement: Loss of ductility in CrSteels due to improper PWHT or service at high temperature (>700ºF)

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DAILY EXAM 5 (Closed) Note: Encircle the letter of only one answer which you think is most appropriate.

1.

Repair Organization is__________ and carries out repairs as per API 510 a. b. c. d.

2.

Which of the following are essential elements of a Quality control system of a repair organization? a. b. c. d.

3.

Use of a external micrometer Ultrasonic testing Using LPI None of above

In API-510, the term “RBI” means: a. b. c. d.

6.

CUI Caustic embrittlement Erosion All of the above

Corrosion and minimum thickness evaluation may be conducted by? a. b. c. d.

5.

Organisational Structure and documentation methods Statements about working procedures Statement of controls to ensure quality All of the above

Which of the following is a typical deterioration that can take place on the external surfaces of insulated vessels? a. b. c. d.

4.

Holder of ASME certificate & appropriate code symbol stamp Owner-user Contractor under contract with owner-user Any of above

Repairing Before Inspection Report Based Inspection Repair Based Inspection Risk Based Inspection

Which of the following defines the term “hold point” in inspection practice? a. b.

For a vertical pressure vessel held in position by guy-wires, the holding points on the vessels connected to guy-wires. A support lug welded onto the vessel.

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c. d. 7.

Repair on pressure vessels will: a. b. c. d.

8.

b. c. d.

Creep Fatigue Erosion All of above

A Shell with nom. I.D. = 2200 mm is rolled and the inspector observed following readings, D max = 2215mm, D min = 2195 mm. Should the shell be: b. c. d. e.

11.

Creep cracking is caused due to loss of ductility at low temperatures. Creep is high temperature phenomenon and is dependent upon time, temperature and stress Hydrogen attack aggravates creep cracks b and c

The failure mechanisms common in vessels subjected to vibrations is: a. b. c. d.

10.

Restore the vessels to intended (original)design conditions Not change the rating of vessel. a and b above Restore the vessels to some other usable conditions

Which of the following best describes creep cracking? a.

9.

A point beyond which work may not proceed until inspections have been performed and documented A holding clamp used for aligning the joints for welding

Accepted Rejected Accept after NDT Depends on opinion of inspector.

Widely scattered pits may be ignored if which of the conditions are satisfied: a. b. c. d.

Thickness available at bottom of pit is greater than one half the required vessel wall thickness The total area of the pits does not exceed 7 square inches within any 8 inch diameter circle The sum of their dimensions along any straight line within the circle of diameter 8 inches does not exceed 2 inches All of the above

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12.

Which of the following are areas on pressure vessel which are susceptible to CUI? a. b. c. d.

13.

Corrosion under insulation (CUI) due to environmental factors like humidity, moisture, will be more pronounced at temperature: a. b. c. d.

14.

b. c. d.

Recalculate t minimum for current operating conditions using E < 1. Recalculate t minimum for current operating conditions using E = 1. Recalculate t minimum for design conditions using E = 1. Monitor the thickness during the run.

A horizontal vessel is provided with 2:1 elliptical heads on both ends. The tan – tan shell length = 120 in. vessel dia = 40 in. What will be overall length of the vessel? a. b. c. d.

16.

100F to 3500F for CS & 1400F to 4000F for SS More than 4000F Lower than 10ºF CUI is independent of temperature

What can be done to extend the life of a 2” thk. vessel with a corroded area in the shell plate 6 inches from the weld, a joint efficiency of less than 1, and a corrosion thickness currently near the minimum required thickness? a.

15.

All the area which is below insulation Insulated areas below steam vents Insulated areas exposed to cooling tower mist “b” and “c” above

150 inches 140 inches 160 inches None of above

According to API 510, authorized inspection agency is: a. b. c. d.

Jurisdiction organization Insurance company which under writes insurance of pressure vessels Inspection organization of owner-user Any of above

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17.

Shells of vessels adjacent to inlet impingement plates are susceptible to: a. b. c. d.

18.

For all repairs and alterations under API 510, the ultimate responsibility rests with: a. b. c. d.

19.

Owner user API Committee API-510 Inspector Jurisdiction authority

Which of the following changes on a vessel could be termed as an alteration? a. b. c. d.

20.

Stress-corrosion cracking Erosion Hydrogen embrittlement Tamper embrittlement

Addition of a reinforced nozzle of size equal to an existing nozzle Addition of a nozzle not requiring reinforcement Addition of a reinforced nozzle of greater size, at same location. Only “b” and “c”

A pressure vessel has design pressure = 300 psi. Its safe stress values at ambient and designed temperatures are 17100 psi and 16300 psi respectively. The hydrostatic test pressure and inspection pressure for above will be: a. b. c. d.

450 psi and 409 psi and 415 psi and None of the

346 psi 315 psi 300 psi above

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DAILY EXAM 5 (Closed)

Answer Key

Q. NO.

ANSWER

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

D D A B D C C D B A D D A C B D B A C B

REFERENCE

API 510, 3.5.4 API 510, 4.2.3 General Knowledge of any Inspection API 510, 5.7.2 API 510, 6.3 General Knowledge of any Inspection API 510, 3.5 3 General Knowledge of any Inspection General Knowledge of any Inspection ASME Sec VIII, UG – 80 a (1) API 510, 7.4.3 API 510, 5.5.6.2 API 510, 5.5.6.1 API 510, 7.4.5 ASME Sec VIII, UG – 32 (d) ASME Sec VIII, 3.4 General Knowledge API 510, 4.1 API 510, 3.2 ASME Sec VIII, UG – 99 (b) and (d)

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POINTS TO RECALL DAY 5

1.

For new service, or for changed service, if corrosion rate is not known, The corrosion rate may be calculated based on corrosion data for similar service, or based on published data. If both are not available, on-stream determination after 1,000 hours shall be made to establish the corrosion rate.

2.

MAWP =

SEt

/(R+0.6t)

Where t Cn 3.

For corrosion area of considerable size; thickness averaging along most critical element shall not exceed following length (l) measured longitudinally: e. f.

3.

= t actual – 2 x Cn = metal loss up to next inspection

Vessel I.D. < 60”... l = D/2 or 20” use smaller value Vessel I.D. > 60”... l = D/3 or 40” use smaller value

The widely scattered pits, can be ignored if: a. b. c.

Remaining thickness below the pit is greater than half the required thickness. Total pit area does not exceed 7 square inches within 8 inch diameter circle. Total sum along any line in circle does not exceed 2 inches.

4.

As alternative, evaluation of thinning of pressure retaining walls may be performed by employing methods outlined in ASME Sec. VIII Div. 2, in consultation with the Pr. Vessel Engineer.

5.

For surface remote from weld, (weld E < 1), shell thickness can be recalculated with E = 1. Shell area is considered remote from weld if it lies on either side weld beyond 1” or 2 times the thickness (whichever is greater).

6.

For dished Heads, the Crown portion lies within a circle concentric to dish but with circle dia. = 0.8 x shell dia.

7.

For Ellipsoidal or Torispherical heads, crown portion thickness can be recalculated considering the Crown as part of sphere of 127

IET/CH/TP/002-R2, Sept. 11

radius equal to D, (for standard Torispherical) or K1 D (for Ellipsoidal). Where, D is shell diameter 8.

For ellipsoidal head K1 depends on D/2h ratio (h=head depth) For 2:1 Ellipsoidal Head, K1 = 0.9

9.

Fitness for Service evaluations are performed as per API RP 579.

10.

RBI methodology is based on assessment of Likelihood of failure (LOF) and Consequence of Failure (COF) and is conducted and documented as per API RP 580.

11.

RBI assessment may be used as an alternative to establish the Frequency of Internal and External Inspections.

12.

If 10 year limit Is increased based on RBI, the RBI assessment shall be reviewed and approved by both Pressure Vessel Engineer and Inspector at intervals not exceeding 10 years or more often if LOF or COF changes.

------------------------------End---------------------------

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DAILY EXAM – 6 (Open) Note: Encircle the letter of only one answer which you think is most appropriate.

1.

Following four new seamless std. torispherical heads are available for use for following design conditions. Choose the correct one. Design pr = 235 psi, Head I.D = 72’’, S = 20000 psi with no C.A. a. b. c. d.

2.

0.9882”. 0.4886”. 0.6184”. 0.7496”.

Provided Provided Provided Provided

thk thk thk thk

after after after after

forming forming forming forming

= = = =

1.0” 0.5” 0.625” 0.75”

Design Design Design Design

thk thk thk thk

= = = =

0.7382”. 0.9788”. 0.4985”. 0.7377”.

Provided Provided Provided Provided

thk thk thk thk

after after after after

forming forming forming forming

= = = =

0.75” 1.0” 0.5” 0.75”

72’’ 60’’ 48’’ 54’’

For head in Q.2 (Ellip. Head - B) value of crown radius for API 510 analysis can be taken as: a. b. c. d.

5.

= = = =

Head in Q1 (torisph Head-A) is to be analysed according to API 510, after placing the vessel in service for 10 years. For the purpose of API 510 analysis, value of crown whose radius can be taken as: a. b. c. d.

4.

thk thk thk thk

Following four new seamless (2:1) ellipsoidal heads are available for the following design conditions. Choose the correct one. Design pr = 332 psi, Head I . D = 60’’ S = 20000 psi with no C A a. b. c. d.

3.

Design Design Design Design

72’’ 60’’ 48’’ 54’’

The crown portion for head A may be considered as the portion lying entirely within a circle whose centre will be same as head centre and diameter will be a. b. c. d.

68.5’’ 36.4’’ 57.6’’ 54.0’’

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6.

For head B, the crown portion would lie within similar circle of diameter: a. b. c. d.

7.

Required minimum thickness of crown portion for analysis as per API 510 for head A shall be: a. b. c. d.

8.

1.0 inch 1.50 inch 1.125 inch 1.25 inch

After 10 years of service, extensive corrosion was observed on the shell (shell Nominal thickness as per above question) over a patch lying entirely beyond 6 inches from weld for the vessel above. Thickness measured in this area was only 0.96’’, while on weld area, the corrosion was within expected limits. If Corr. Allowance required for remaining life is 1/16” (0.06”), the vessel is: a. b. c. d.

11.

0.4490” 0.4262’’ 0.3652’’ 0.4863’’

The minimum nominal thickness of new cylindrical shell with design pr=555 psi inside diameter = 58’’, S= 20000 psi and E = 0.85 with corrosion allowance of 1/8’’ will be: a. b. c. d.

10.

0.3695’’ 0.4075’’ 0.4235” 0.4825’’

Required minimum thickness for crown portion for head B as per API 510 shall be: a. b. c. d.

9.

60’’ 30’’ 54’’ 48’’

Safe for design conditions Unsafe for design conditions Safe only if welds are fully radio graphed and ok Safe only if welds are UT checked and OK

According to API 510, for vessels with I.D. = 48’’ corrosion averaging along most critical element can be done over a length not exceeding: a. b. c. d.

12 16 20 24

inches inches inches inches 130

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12.

If diameter of vessel above in Q. 11 is changed to 72’’, the length for corrosion averaging will be: a. b. c. d.

13.

36 24 40 18

inches inches inches inches

A cluster of scattered of pits was observed on exterior of vessel shell. The description of pits is as follows: Nominal vessel thickness = 5/8” Corrosion allowance = 1/8 inch Total area of pits = 5.8 sq inch Pit of largest depth: 0.5 inch dia., 0.20” deep All pits could be enclosed in a circle of 8 inch dia. and maximum cumulative length is 1.75 inch within the circle. a. b. c. d.

14.

If in Q.13 above, depth of deepest pit was 0.15’’, cumulative length was 2.3 inch ( other data remaining same) your analysis will be: a. b. c. d.

15.

Pits may be ignored as per API 510 Pits are unsafe as the total area pf the pits is beyond limits The cluster is unsafe as depth of deepest pit is beyond limits The cluster is unsafe , they are exceeding cumulative length criteria

The cluster is still safe Cluster is unsafe as depth is still beyond limit Unsafe as cumulative length is beyond limit b and c

If total area of cluster is 8 sq inch other data remain same as Q.13, what is your evaluation? a. b. c. d.

Cluster Cluster Cluster Cluster

is is is is

unsafe due to increased cluster area unsafe due to pit depth still being unsafe unsafe due to a and b safe

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DAILY EXAM – 6 (Open) Solutions 1.

Thickness of new torispherical head is given by ASME formula, t = 0.885 PL SE – 0.1 P

L = Crown radius .˙. L = Diameter of head E = 1 (seamless)

= 0.7496 mm Provided thk of 0.75” is ok. Correct answer:

2.

d

Thickness of new Ellipsoidal head (2:1) is given by ASME Formula: t=

PxD 2SE-0.2P

= 332 x 60 2 x 20000 x 1 – 0.2 x 332 = 19920 39933.6 = 0.4985” Provided thk = 0.5” (OK) Correct Answer: c

3.

For Torisph. Head, D = 72” For API 510 analysis Crown Radius = Diameter = 72” Correct answer: a 132

IET/CH/TP/002-R2, Sept. 11

4.

For 2:1 Ellip head, for API 510 analysis Crown radius = 0.9 D = 54” Correct answer: d

5.

Crown portion lies in circle of diameter equal to 0.8D = 0.8 x 72 = 57.6” Correct answer: c

6.

Crown Portion lies in circle of dia. equal to 0.8D = 0.8 x 60 = 48” Correct answer: d

7.

For torisph head, for crown portion, use hemisphere formula using R = D t =

PxR 2SE – 0.2P

t=

235 x 72 2SE - 0.2P

=

use R = D = 72” S = 20000 PSI E=1 P = 235

16920 39933.6

= 0.4235” Correct answer: c

8.

Again, use hemispherical head formula for Crown part: t=

PxR 2SE – 02P

= 332 x 0.9 x 60 2SE – 0.2P

for Hemispherical head, use R = 0.9 D S = 20000 psi E=1 P = 332

= 332 x 54 39933.6 = 0.4489 Correct answer: a 133

IET/CH/TP/002-R2, Sept. 11

9.

Required thickness t

= P X R SE – 0.6P

=

555 x 29.125 20,000 x 0.85 – 0.6 x 555

=

16164 16667

=

0.967” + 0.125

=

(R = 29.125” ,Half dia.)

1.09

Correct answer: c

10.

Thickness away from weld (required thk) t=

t=

=

PxR SE – 0.6P

take: E=1

555 x 29.125 20,000 – 333 0.83”

Available shell thickness Excluding required C.A.= 0.96”-0.06” = 0.9” 0.9” > 0.83” . . . (Safe) Correct answer: a 11.

ID or 20” use smaller value (ID ≤ 60”) 2 24” or 20 - - - - - - - - 20” Correct answer: c

12.

ID 3

or 40” use smaller value (ID › 60”)

72 3

or 40”

24 or 40” . . . . 24” Correct answer: b 134

IET/CH/TP/002-R2, Sept. 11

13.

Area within 8” diameter circle = 5.8 sq. in. (OK) Length along straight line in circle = 1.75 (OK) Depth

5/8” – 1/8”

0.25” (OK)

Correct answer: a

14.

Length 2.3 inch > 2” ---------- (NOT OK) Correct answer: c

15.

Area 8 sq. in > 7 sq. in -------- (NOT OK) Correct answer: a

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POINTS TO RECALL DAY 6 1.

Frequency of inspection: a. External visual: 5 years or same as internal (or onsteam) inspection, use smaller duration. b. Internal/on-stream: Smaller of half remaining life or 10 years, if remaining life is < 4 years full remaining life up to maximum of 2 years. g. For non-continuous service – external same as (a) above but internal will be after 10 years of actual exposed life.

2.

On-Stream inspection may be substituted for internal inspection if: a. b.

3.

There is no access to enter. If Corrosion rate is less than 5 mpy and R. L. is more than 10 years there are no questionable conditions found during external inspection. Also, the vessel is not subject to Environmental damage or Strip/plate lined.

Remaining life = Remaining C.A. / Corrosion rate Corrosion rate =

4.

metal loss over a period period of metal loss

Pressure test: Min. Test temp.

= =

MDMT + 30ºF (thickness > 2”) MDMT + 10ºF (thickness ≤ 2”)

Perform Pneumatic test, if hydro is impractical. 5.

Inspection records shall have 4 type of information: a. b. c. d.

Design and Construction (permanent) records Running (progressive) inspection records Repair and alteration (modification) records Fitness for service records

6.

For vessels whose material is not known, MAWP can be calculated assuming stress value for A 283 Gr. C material and Joint Efficiency equal to 0.7.

7.

Pressure relieving devices: Inspection interval not to exceed 5 years normally but for clean non-corrosive service may be 10 years. 136

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8.

Authorization for repairs/alteration of vessels constructed as per: ASME Sec. VIII, Div. 1: Repairs — API inspector Alterations — API inspector and P.V. engineer ASME Sec. VIII, Div.2: Repairs & Alterations — API inspector and P.V. engineer

9.

If PWHT is impracticable, materials under P No. 1 (group 1, 2, 3) and P No. 3 (group 1, 2) shall be repair welded as follows (if impact testing is not required). a.

Preheat to 300 degrees F for a distance 4” or 4t on either side of groove (t = weld metal thickness)

b.

Welding process shall be GTAW

c.

Control Interpass temperature not to exceed 600 degrees F

SMAW, GMAW, or

10.

If impact testing is required and PWHT is impracticable, the materials under P No. 1, 3, 4 shall be welded as follows:

11.

Adopt SMAW/GMAW/GTAW process — with temper bead of half bead technique

12.

Requalify the procedures as per table 7-1

13.

Use low Hydrogen Electrodes. Carry out Hydrogen bake out treatment if required (Electrodes designation > H4)

14.

For all other materials other than 12 and 13 above, PWHT shall be carried out after repair if it was carried out originally as per code of construction.

15.

Local PWHT may be substituted for 360-degree banding if: Original PWHT was not due to service requirement effects of Local strains/distortions are considered Pre-heat & maintenance of 300 deg. F during welding PWHT temp is maintained beyond the weld up to twice base metal thickness

16.

Heat is applied to any nozzles /attachments within PWHT area.

17.

For repairs of following:

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18.

Cracks: By preparing V or U-shaped groove and depositing weld metal — Cracks at area of stress concentrations (i.e., nozzle welds) shall not be repaired without consulting the Pressure vessel engineer. b. Localized corroded area: By weld deposit. Low strength electrodes may be used if thickness of deposit is increased by ratio of B.M. strength to W.M. strength and — Depth of deposit does not exceed half of thickness — Increased thickness is blended with 3:1 taper

19.

For repair welds, the weld preparation before welding, and the completed weld shall be checked by PT or MT. Additionally, the butt-welds shall be radiographed by the rules of original Code of construction (depending on joint efficiency).

20.

The carbon and alloy steel materials used in making repairs and alterations shall not have carbon content over 0.35%.

21.

Pressure test is required after repair/alterations, if authorized inspector thinks it necessary. Pressure test is normally required after alteration.

22.

Insert patches must be with full penetration welds. Fillet patches shall be approved by P.V. Engineer. Normally, a fillet patch equivalent to reinforced opening is okay.

23.

Normally, temporary repairs are replaced by permanent repairs at next available maintenance opportunity. But temporary repairs can remain for longer period if approved by P.V. engineer.

24.

Non-penetrating nozzles (including pipe caps) are accepted method of long term repairs for other than cracks. Full encircle lap band is considered as long term repair for other than cracks. Full encircle lap band is considered as long term repair for other than cracks.

25.

Re-rating calculations shall be done by pressure vessel engineer, and the inspector shall oversee the new stamping or new name plate showing rerating (new MAWP, temp.) is attached to vessel.

26.

For Insulated vessels, CUI is likely to occur If there is possibility of moisture ingress and operate between 10 to 350 degrees F. 138

IET/CH/TP/002-R2, Sept. 11

DAILY EXAM – 7 (Closed) Note: Encircle the letter of only one answer which you think is most appropriate.

1.

For corrosion area of considerable size; thickness averaging along most critical element shall not exceed following length for 48” ID vessel and 72” ID vessel. a. b. c. d.

2.

All the area which is below insulation Insulated areas below steam vents Insulated piping exposed to cooling tower mist “b” and “c” above

Corrosion under insulation (CUI) due to environmental factors like humidity, moisture, will be more pronounced at temperature a. b. c. d.

5.

Carbon content <0.35% and compatible with original material Carbon Equivalent <0.35% and of known weldable quality Carbon Equivalent <0.35% and compatible with original material Equivalent weldable quality material

Which of the following are areas on the pressure vessel which are susceptible to CUI? e. f. g. h.

4.

40” respectively 24” respectively 24” respectively the above

A carbon steel pressure vessel has to be repaired with the substitute plate of carbon steel with: a. b. c. d.

3.

20” and 16” and 20” and None of

25°F to 250°F More than 250°F Lower than 25ºF CUI is independent of temperature

For a vessel find estimated remaining life and next planned external inspection if actual thickness measured during inspection is 0.45” and minimum required thickness is 0.37”. Estimated corrosion rate is 10 mpy. a. b. c. d.

10 years, 5 years 8 years, 5 years 8 years, 4 years 10 years, 10 years

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6.

In above question, if estimated corrosion rate is 20 mpy. The next planned internal and external inspection shall not be later than: a. b. c. d.

7.

years years years years

12 Years, 5 years 10 Years, 10 years 10 Years, 5 years None of the above

1.5 years, 3 years 2 years, 2 years 1.5 years, 1.5 years b and c

A stainless steel cladded vessel, working in hydrogen environment at elevated temperature, repair of the missing /corroded cladding is to be carried out. What heat treatment on base metal (prior to cladding repair) and what NDT should be done after clad repair is performed. a. b. c. d.

10.

4 4 2 5

For a vessel, remaining life is estimated as 3 years from now, next planned internal and external inspection may be planned _______ years from now. a. b. c. d.

9.

years, years, years, years,

For a vessel, remaining life is estimated as 24 years from now, next planned internal and external inspection shall not be later than: a. b. c. d.

8.

8 4 2 8

Local post weld heat treatment and MT check Local post weld heat treatment and RT check Base metal out gassing and PT check Base metal out gassing and MT check

Which of the following is / are to be undertaken in case the ownership and location of vessel are changed? a. b. c.

d.

The vessel shall be hydro tested only. The vessel shall be internally and externally inspected before it is re-used. The allowable conditions of service shall be established and the next period of inspection shall be established for the new service. Only “b” and “c” 140

IET/CH/TP/002-R2, Sept. 11

11.

After completion of repairs, a pressure test: a. b. c. d.

12.

After completion of alterations a pressure test is: a. b.

c. d.

13.

c. d.

Welding shall be done using SMAW/GMAW/GTAW Weld shall be pre-heated to 300°F (min) and interpass temperature limited to 600°F Pre-heating to be maintained up to 4” or four times thickness (whichever is higher) on either side of weld groove. All of the above shall be done.

Who is responsible for re-rating calculations for re-rating of pressure vessels? a. b. c. d.

16.

Repairs for vessels that comply with Sec. VIII, Div. 1 Alterations for vessels that comply with Sec. VIII, Div. 1 Repairs for vessels that comply with Sec. VIII, Div. 2 Alternations for vessels that comply with Sec. VIII, Div 2

For vessel with M.O.C. = 516 gr 70, PWHT was carried out initially as required by construction code, major welding repairs were carried out. PWHT is inconvenient. What can be done to avoid the PWHT? Impact testing is not required. a. b.

15.

Normally required Subject to approval of the jurisdiction (where applicable) appropriate NDE shall be required where pressure test is not performed Generally not required Only “a” and “b” above

Authorization for which of the following approval from pressure vessel engineer is not mandatory: a. b. c. d.

14.

Must always be conducted. Shall be applied if the authorized pressure vessel inspector believes that one is necessary. Must never be conducted. Shall be conducted only if repair is done on pressure parts.

API certified inspector The pressure vessel engineer The national board inspector Corrosion expert

For avoiding PWHT after welding repair is done on Vessels with M.O.C. falling in P Nos. 1, 3, 4 (with impact testing), The welding repair shall be done with:

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IET/CH/TP/002-R2, Sept. 11

a. b. c. d.

17.

Procedure qualification in above question shall be done using: a. b. c. d.

18.

Insert patch with full penetration weld Insert patch with partial penetration weld A full encirclement lap band a and c only

API 510 requires that NDE of repair welds shall include: a. b. c. d.

20.

Temper-bead technique Half-bead technique Any one (a) or (b) None of the above shall be used.

Which of the following type of patches are permitted by API 510 for repairs on pressure vessels? a. b. c. d.

19.

Procedure qualification as per ASME Sec. IX only Procedure qualification shall be done as per Sec. IX and API-510 Any one of the above is okay Procedure shall be qualified as per API 1104

Prior to welding, the area prepared for deposit be examined by MT or PT After weld is completed it shall be examined again by MT or PT Any one of a or b Both of a and b

If remaining life for a vessel is estimated as 2 years from now, next planned internal and external inspection shall not be later than: a. b. c. d.

1 year, 1 years 2 years, 2 years 1 years, 2 years Any of the above

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IET/CH/TP/002-R2, Sept. 11

DAILY EXAM – 7 (Closed)

Answer Key

Q. NO.

ANSWER

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

C A D A C C C D C D B D A D B B C D D B

REFERENCE

API API API API API API API API API API API API API API API API API API API API

510, 510, 510, 510, 510, 510, 510, 510, 510, 510, 510, 510, 510, 510, 510, 510, 510, 510, 510, 510,

7.4.2.1 8.1.4 5.5.6.2 5.5.6.1 6.5.1.1 and 7.2.1 6.5.1.1 and 7.2.1 6.5.1.1 and 6.4.1 6.5.1.1 and 6.4.1 8.1.5.4.3 6.2.2.2 5.8.1.1 5.8.1.1 8.1.1 8.1.6.4.2.2 8.2.1 8.1.6.4.2.3 and 8.1.6.2.1 8.1.6.4.2.3 f (7) 8.1.5.2.1 and 8.1.5.1.3 8.1.7 6.5.1.1 and 6.4.1

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IET/CH/TP/002-R2, Sept. 11

POINTS TO RECALL DAY 7 1.

Procedure qualifications give suitability of weld for required mechanical properties (i.e., strength, ductility), while performance qualifications show ability of the welder to make sound weld.

2.

Tension test gives tensil value, while bend test shows ductility and soundness. Radiography also indicates soundness. Thus, Procedure Qualification : by Tension test + Bend test Performance Qualification: by Bend test or Radiography

3.

Tensile test for procedure qualification is passed if failure is in: a. Weld metal at strength>= Base metal SMTS or b. Base metal at strength>= 95% of base metal SMTS.

4.

Bend test crack shall not exceed 1/8” in any direction. Radiography criteria are stricter than radiography for job.

5.

P-numbers represent parent metal classification of similar composition and properties, i.e., similar strength and ductility. F-numbers give similar usability aspects of filler material. A-numbers give similar chem. comp. In “As welded” condition.

6.

Essential variables (EV), if changed require new procedure qualification. Non-essential variables (NEV) may be changed without new procedure qualification.

7.

Supplementary essential variables (SEV) are considered as (EV) only if there is impact strength requirement. Otherwise they are “non- essential” variables.

8.

EV and SEV are included in PQR document. EV, SEV and NEV are included in WPS document.

9.

PQR gives data used in PQR test and test results, and cannot be revised.

10.

WPS gives parameters to be used in production job, and must be within ranges qualified by the PQR test.

11.

WPS may be revised within the EVs qualified. The NEVs can always be revised without affecting validity of PQR.

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IET/CH/TP/002-R2, Sept. 11

12.

For performance, 1G is flat, 2G is horizontal, 3G is vertical and 4G is overhead position. Pipe 5G qualifies 1G, 3G and 4G, but pipe 6G qualifies all positions.

13.

Welder who welds test coupon for procedure qualification test in certain position also qualifies for performance in that position if procedure Qualification was OK

14.

Performance Qualification of welder is affected if he has not welded with that process for last 6 months.

15.

Inspector can revoke performance qualification if welder is repeatedly unable to produce satisfactory welds meeting the requirements.

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IET/CH/TP/002-R2, Sept. 11

DAILY EXAM 8 (Open) Note: Encircle the letter of only one answer which you think is most appropriate.

1.

The gamma ray radiography has minimum density of: a. b. c. d.

2.

2.0 4.0 No upper limit is prescribed Depends on the viewed

In a radiographic examination of butt weld (Thk = 3.5 in.) the Geometric unsharpness shall not exceed: a. b. c. d.

3.

0.02” 0.04” 0.03” None of above

Select suitable hole type (source side) penetrameter for following weld joint:

Weld reinf. = 1/8" thk

7/8"

z a)

a. b. c. d. 4.

No. 20 No. 25 No. 30 None of the above

If type of penetrameter in above question is changed to wire type what shall be the wire designation (wire diameter in inch) a. b. c. d.

5.

Backing strip = 3/16" thk

0.025 dia. (No. 10) 0.016 dia. (No. 8) 0.032 dia. (No. 11) None of the above

For steel plates and welds to be checked by LPI, what shall be the penetration time for penetrant? a. b.

10 min for weld, 5 min for plate 5 min for both 146

IET/CH/TP/002-R2, Sept. 11

c. d. 6.

After applying the developer the examiner checked four welds for surface defects after following period: weld A – After 5 minute, weld B after 10 minutes, weld C was checked after 30 minutes and welds D after 65 minutes. Which of the welds were checked wrongly? a. b. c. d.

7.

8.

A and B C and D D only A and D

4 4 3 3

inch inch inch inch

to to to to

12 inch 10 inch 10 inch 8 inch

Calculate estimated inspection period for external and internal inspection for a vessel whose remaining life is estimated as 12 years. a. b. c. d.

Internal = 6 years, external = 10 years Internal = 6 years, external = 5 years Internal = 5 years, external = 10 years None of the above

As per WPS the material used is SA516 Gr.70 and the electrode used is E-7018. What is the P# and F#? a. b. c. d.

10.

Weld Weld Weld Weld

For MT examination by Prod technique the spacing between prods shall be between a. b. c. d.

9.

10 min for both 5 min for weld, 10 min for plate

1, 4, 2, 4,

4 1 4 2

If the corrosion rate of a vessel is determined to be less than a given amount per year, it is possible to exempt the vessel from internal inspections. What is the value of the corrosion rate that cannot be exceeded? a. b. c. d.

0.001”per year 0.001” between inspections not to exceed 5 years between inspections. 0.005” per year. 0.005” between inspections not to exceed 3 years between inspections 147

IET/CH/TP/002-R2, Sept. 11

11.

12.

A P No. 1 material that is plate has been rolled into a cylinder and butt welded. The cylinder is exactly 1-1/4” thick, and it is used in the repair of a pressure boundary on a U stamped vessel, the following is a true statement.

a.

It must receive full radiography.

b. c. d.

It may be not spot radiographed. It may not be fully radiography. It may receive either spot, full, or no radiography depending on the original MDR form

Dezincification occurs by attacking metals which contain: a. b. c. d.

Copper - zinc alloys containing copper used in water service Copper - zinc alloys containing copper used in water service Copper - zinc alloys containing copper used in caustic service Copper - zinc alloys containing copper used in acidic service

less than 95% of less than 85% of less than 85% of less than 95% of

DAILY EXAM 8 (Open) Answer Key Q. NO. 1 2 3 4 5 6 7 8 9 10 11 12

ANSWER A B B D D D D B A C D B

REFERENCE ASME V, T-282.1 ASME V, T-285 ASME V, TABLE T-276 ASME V, TABLE T-276 (correct wire no 9) ASME V, TABLE T-672 ASME V, TABLE T-672 ASME V, FIG T 622.1.1 API 510 6.3.1 AND 6.4.1 ASME SEC IX, TABLE QW-422, QW-432 API 510 6.5.2.1 ASME SEC VIII, UW-11(a) (2) & UCS-57 API 572, 8.3.3

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IET/CH/TP/002-R2, Sept. 11

POINTS TO RECALL DAY 8 1.

2.

GENERAL: a.

ASME Sec. V is NDT procedure/methods code and is applicable only if it is referenced by the relevant construction code. The extent of NDT and acceptance standards is given in relevant construction code.

b.

NDT equipment and their calibration shall be as per ASME Sec. V.

c.

Examiner is NDT person in employment of fabricator or repair organization. Inspector means Authorized Inspector who finally accepts/rejects NDT results.

FOR RT: a.

Satisfactory radiograph shall meet requirements of density and IQI image (2T hole for hole type and designated wire for wire type).

b.

Backscatter: Light image of B on dark background - Unacceptable

c.

Density Limitations: Min 1.8 for X Ray / 2.0 for G-Ray Max 4.0 for X / G Ray Density Variation = -15 % to + 30%

3.

d.

Double wall viewing (DWDI) - Up to 3.5” outside diameter

e.

Penetrameter Selection: Table T-276. Thickness includes weld reinforcement. But not backing.

f.

Penetrameter shall be normally placed on source side. If not possible, it may be placed on film side with lead letter “F”.

FOR PT: a.

Control of Contaminants: Sulphur (for Nickel alloys) shall not exceed 1% of residue. Chlorine + Fluorine (for S.S. and Titanium) shall not exceed 1% of residue.

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IET/CH/TP/002-R2, Sept. 11

b.

Temp. shall be between 10oC to 52oC, for standard procedures.

c.

Penetrants are colour (visible) type and fluorescent type. Each of these have:


water washable




post emulsifying




solvent removable Thus, total 6 categories of penetrant are available.

d.

Emulsifier is applied after applying penetrant and required dwell time is completed. Lipopholic emulsifier is applied without pre-rinsing. Hydropholic emulsifier is applied after pre-rinsing.

e.

For dwell time for penetrant and developer refer Table T672.

f.

After applying developer, interpretation shall be done within 10 to 60 minutes.

g. 4.

All penetrant materials should be from same manufacturer

FOR MT: a.

b.

Prod Technique:
Use direct (rectified) current for magnetization
Prod spacing 3” to 8”
Useful for surface and sub-surface defects. Yoke Technique:
Use D.C. or A.C. or permanent magnet
Suitable for surface defects only.

c.

Calibration: Equipment Ammeter to be calibrated once a year comparing with standard Ammeter, take 3 readings. Deviation shall not exceed ±10% of full scale.

d.

Lifting Power of Yokes
AC shall have lifting power of at least 4.5 kg (10 lb.)
DC shall have lifting power of at least 18.1 kg (40 lb.)
Minimum two examinations on each area, the second is perpendicular to first

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FOR VT: a.

5.

There shall be a written procedure for VT indicating the essential and non-essential variables. b. The procedure used to be re-qualified if the essential variable is changed. c. The acceptance of procedure is the criteria to detect a defect of width not more than 1/32” (0.8 mm) made on similar surface. d. The examiner shall be annually tested for Jaeger J-1. e. For direct Visual testing, the eye of examiner shall be at an angle of min.30 deg. to the surface, and within 24 inches from surface SE-797 UT MEASUREMENT: a.

Pulse-echo method can be adopted up to 200°F

b.

Apparatus: 3 types a. CRT read out b. CRT + direct read out c. Direct thickness read out

c.

Search Units: 3 types a. Straight beam contact type b. Delay line type (delay block to minimize dead zone) c. Dual element type. There are two crystals set at a small range. d. Low roof angle used for higher range and higher angle for low range.

d.

High thickness measurement: Use of multiple echoes is made. (i.e., for thickness between 50 mm and 60mm, use 10mm calibration block then 5th back echo will be 50 mm and 6th will be 60mm. Set the 5th echo to zero and 6th at the screen range. The screen is calibrated to 50-60mm.

e.

While taking measurement for high temperature condition a positive error of 1% per 55°C (100°F) results. Hence temperature correction is necessary.

f.

CRT read out is recommended on corroded and rough surface.

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IET/CH/TP/002-R2, Sept. 11

DAILY EXAM 9 (Closed) Note: Encircle the letter of only one answer which you think is most appropriate.

1.

Cracks are likely to occur in or adjacent to welded seams in which of the following vessels? a. b. c. d.

2.

If alloy steels have undergone “temper embrittlement”, the appropriate testing to confirm the same is: a. b. c. d.

3.

Brinell & Rockwell Izod & Charpy V-notch Charpy V-notch only is acceptable. Brinell only is acceptable.

The API authorized pressure vessel inspector may give prior authorization for repairs that do not involve: a. b. c. d.

5.

Hardness testing Impact testing Ductility testing Tensile strength testing

The rules for impact testing of carbon steel in Section VIII vessel materials require what kind(s) of impact test? a. b. c. d.

4.

Vessels constructed of high strength steels (above 70,000 psi) Vessels made from coarse grain steels Vessels made of low chrome materials and operating at high temperature All of the above

Pressure tests Radiography Pneumatic testing of pads Final visual inspections

Prior to witnessing a pneumatic test of a pressure vessel, the inspector should: a. b. c. d.

Ensure that welds around nozzles were inspected by PT or MT prior to commencement of test. Ensure that test pressure is maintained throughout the leak testing inspection. Ensure that all butt welds were UT checked prior to commencement of test. Both a and b

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6.

Widely scattered pits may be ignored as long as the following conditions are satisfied: i. Thickness at bottom of pits is greater than one half the vessel’s required wall thickness ii. The total area of the pits does not exceed 7 square inches (45 square centimeters) within any 8-inch (20-centimeter) diameter circle. iii. The sum of their dimensions along any straight line within the circle does not exceed 2 inches (5 centimeters). iv. ? What is the missing item in “iv” above?

a.

The thickness at bottom of pit must be measured by pit gauge.

b.

The 8”diameter is to be measured from the center of the deepest pit. There are no missing items; there are only 3 items to be considered The total area of the pits cannot exceed 3.5 square inches in a 4-inch diameter circle.

c. d.

7.

Before any repair to a pressure vessel in accordance with its code of construction, what if any additional requirements (over and above those in API 510) may need to be considered? a. b. c. d.

8.

Reduction in likelihood of brittle fracture can be obtained by performing a. b. c. d.

9.

Jurisdictional requirements that might override the API 510 Code. Is repair being done by repair organisation? The quality of the repair materials. The need for qualified welding procedures.

Impact testing Hydrostatic testing PWHT Pneumatic testing

A new vessel has been installed, what must be done in order to accept the vessel for operation? a. A first internal inspection b. A first internal inspection, however if a manufacturer’s data report (U1) assuring that the vessel is satisfactory for its intended service is available the first internal inspection may be waived.

c.

Base line thickness readings must be taken per OSHA 1920 (j).

d.

Base line thickness reading must be taken per OSHA 1910 (j).

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10.

Ordinarily non-metallic coatings and linings can be most effectively inspected by what technique?

a.

Low voltage holiday tester

b. c. d.

Radiography Hammer testing Using a high voltage low current brush type electrode device. (Spark Tester)

11. Titanium alloys are subject to loss of ductility in certain environments, what is this condition called? a. b. c. d. 12.

Which of the following describes a crack in metal? a. b. c. d.

13.

run parallel to the surface. run at right angles to the surface. are usually wide at one end and narrow at the other. always run slant to the surface.

c.

Cracking due to operating at high temperatures above 700°F Loss of ductility and notch toughness due to exposure above 700°F Flaking of the metal surfaces, causing dip pits

d.

Cracking due to low temperature service

Thermal fatigue cracks usually are a. b. c. d.

15.

Cracks Cracks Cracks Cracks

Temper embrittlement is best described as: a. b.

14.

High temperature embrittlement Low temperature embrittlement Hi-alloy effect Hydriding

Branching, Transgranular and initiate from within the material. Dagger shaped, intergranular and initiate form within the material. Dagger shaped, oxide filled and initiate form the surface. Dagger shaped, clean and intergranular.

Erosion/Corrosion mitigation can be achieved by a. b. c. d.

Increasing the pipe diameter to decrease velocity Increasing surface hardness by using harder alloys or hard facing Using corrosion resistant alloys All of the above.

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16.

Which of the following is a major concern when operating vessels that utilize the slurries with solid suspensions? a. Overheating b. Erosion c. Corrosion d. Cracks

17.

The inspection of a vessel to determine if a hydrogen blister is present is often best performed by: a. Researching the inspection records b. Determine the vessels material to see if hydrogen attack is likely c. Swaying a flash light parallel to the vessel’s surface

d.

18.

When preparing to inspect a vessel which has had previous inspections what is the initial step in preparation for the inspection? a. b. c. d.

19.

Assemble all the required tools to perform the inspection. Review previous inspection records. Advice maintenance of any anticipated repairs. Insure that all non-destructive examinations required have been scheduled.

Which of the following best describes a “Corrosion Button” as might be found in a pressure vessel? a. b.

c.

d.

20.

Recommending metallurgical tests for blisters in a laboratory

Buttons made of highly corrosion resistant material from which corrosion loss can be measured. Buttons which corrode at about the same rate as the vessel’s material and are used to estimate the vessel’s corrosion losses. No such thing exists; there is however a corrosion tab used in vessels.

A form of corrosive product produced by certain chemicals in a vessel when is constructed of high chrome alloy material.

In a PRV in which the major relieving device or main valve is combined with and controlled by a self-activated auxiliary pressure relief valve is: a. b. c. d.

Pilot operated valve Bellow type balancing valve Relief valve Safety valve

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DAILY EXAM 9 (Closed) Answer Key

Q. NO.

ANSWER

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

A B C A A C A C B D D B B C D B C B A A

REFERENCE

API 572, 10.4.4 API 571, 4.2.3.5 ASME VIII, UG-84 API 510, 8.1.1 ASME VIII UG-100 API 510, 7.4.3 API 510, 1.1.1 & 1.1.3 API 571, 4.2.7.6.(d) API 510, 6.2.1.2 API 572, 10.4.6 API 572, 8.3.7 API 572, 10.4.4 API 510, 3.5 g API 571, 4.2.9.5.(a) API 571, 4.2.14.6 a,b,c API 571, 4.2.14.3.b API 572, 10.3.13 API 572, 10.4 .3 API 572, 10.5 API 576, 2.2.1.5

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POINTS TO RECALL DAY 9 1.

Vessel inspections are for the safety, continuity, reliability.

2.

Graphitization in Carbon Steels takes place due to prolonged exposure in 825 to 1400 deg. F range resulting in decomposition of Steel into Ferrite Crystals and Graphite Nodules. In-situ metallography is used to detect the Graphitization

3.

External inspection of Pressure Vessels and Exchangers should start with ladders, platforms, stairways connected to or bearing on vessel.

4.

External surfaces of vessels shall be examined for not only for corrosion but also for leaks, cracks, buckles, etc.

5.

If any settling is seen on vessel, nozzles and adjacent shell area shall be inspected for distortion and cracking.

6.

Hammer test shall be followed by suitable NDT.

7.

Grounding connection resistance shall not exceed 25 ohms but 5 ohms is normally preferred.

8.

In presence of acidic corrodents (PH < 7) hydrogen blistering is expected above and below (close to) liquid level.

9.

Auxiliary equipments (Pressure gauges, sight glass, safety valves etc. may be visually inspected while in service. Undue vibrations shall be arrested by providing additional supports or qualified engineer should determine if these could lead to fatigue failure.

10. First step for internal inspection is review of previous records. 11. For heavy wall vessels at high pressure, major concern is crack damage particularly at the welds (Weld & HAZ). 12. Laminations run slant while cracks run normal to surface. 13. Spark testing is effective method for breaks/leaks in paint, glass, plastic and rubber lining. 14. UT is the primary means of obtaining thickness measurements. Other methods like profile radiography, Step-wedge comparison radiographs, Corrosion buttons, test holes and depth drilling are some other methods. 15. Tamper embrittlement of chromium steel occurs due to loss of ductility due to prolonged exposure to high temperature above 650oF. It can be controlled by limiting "J" factor for base metals and "X" factor for weld metals. 16. All fatigue failure take place due to initiation of surface crack and propagation of crack due to stress fluctuation. There are 3-types of fatigue failures.

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If surface cracks are due to stress concentration, weld undercuts, notches etc. and stress fluctuation due to mechanical reasons (vibrations, water hammer etc.) then it is Mechanical Fatigue. If stress fluctuation is due to temperature swing, it is Thermal Fatigue. If initial surface cracks are due to corrosion, pitting etc., it is Corrosion Fatigue. 17. Corrosion Erosion is due to combined action of corrosion and erosion. It can be reduced by controlling corrosion (by coating or using corrosion resistant materials) and by controlling erosion (by controlling flow velocity, providing harder surface). 18. Caustic embrittlement occurs due to combined action of high caustic strength and higher temperature. It can be controlled by carrying out PWHT and upgrading materials by Nickel alloys. 19. Sulphidation occurs due to sulpher or H2S content in the fluid handled. It can be reduced by using Chromium containing steels as construction materials. 20. Hydrogen blistering takes place due to migration of Hydrogen items in the steel vessel walls. Hydrogen induced cracking (HIC) takes place if several Hydrogen blisters join together in the material. 21. Stress assisted HIC (SAHIC) takes place due to propagation of HIC cracks under effect of applied stress. Crack propagates perpendicular to stress direction. 22. High temperature Hydrogen Attack (HTHA) is due to migration of Hydrogen atoms in the carbon steels which combines with carbon in carbons steel at high temperature to form Methane gas (CH4) which collects at grain boundaries causing internal cracks. It can be reduced by selecting the construction materials according to Nelsen Curves. (The material should be above the point of temperature and Hydrogen pressure).

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MID EXAM (Closed) Instructions: Choose only one answer which you think is most appropriate. Use the attached attempt sheet in answering the following questions.

1.

A vessel made with full penetration double welds shows name plate marking of ‘RT2’. The joint efficiency for this vessel will be: a. b. c. d.

2.

Which of the following are essential elements of a Quality control system of a repair organization? a. b. c. d.

3.

d.

Authorized inspector who is overseeing the repair activities Repair organization who does the repair work The plate marking and cutting persons involved in the repair process The pressure vessel Engineer who approved the repair work

A repair work on a pressure vessel is to be carried out. Who is responsible to have WPS/PQR made for the repair work? a. b. c. d.

5.

Statement of authority and responsibility Welding procedures used for repair/alterations The Control of procedures and Qualifications of NDE personnel All of the above

Who is responsible for transferring the plate marking to the balance plate for a vessel repair work? a. b. c.

4.

0.85 1.0 0.7 None of these

Owner user Repair organization Authorized inspector Third party who does the inspection work

Before entering into a vessel for inspection the vessel shall be evaluated for safety in accordance to: a. b. c. d.

OSHA API ASME/API ANSI

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6.

The __________ shall be responsible to the owner-user for determining that the requirements of API 510 for inspection, and testing are met. a. b. c. d.

7.

RT1 RT2 RT3 RT4

In the above question, if welds were fully radiographed for their entire length, the purpose is to conform to ________ stamping to be put on name plate: a. b. c. d.

9.

Operating personnel

If vessel longitudinal and circumferential welds are type 1 and spot radiographed only, then stamping on name plate will be: a. b. c. d.

8.

Vessel engineer Authorised inspector Repair organisation

RT1 RT2 RT3 RT4

A pressure vessel of 60” ID has three pits within a circle of 7” diameter. The nominal thickness of the shell is 0.75” and the CA is 0.15”. The details and dimensions of the pits are listed below. Your assessment is:

Pit 1: 0.5” dia depth 0.28” Pit 2: 0.8” dia depth 0.22” Pit 3: 0.4” x 0.5”, depth 0.23” a. b. c. d. 10.

The The The The

pit area is more than the acceptable pit length is more than the acceptable pit depth is more than the acceptable pits are acceptable as they are meeting the requirement

Insulation inspection on an insulated vessel with no damage to insulation shall be done by: a. b. c. d.

Removing at least 10% of insulation to check the condition Removing insulation on at least 25% area Removing the entire insulation Not required to remove insulation

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11.

Vessel MAWP of existing vessel will be affected: a. b. c. d.

12.

The Code formula for a torispherical head thickness as per ASME Section VIII Div. 1 actually gives the thickness required: a. b. c. d.

13.

b. c. d.

FFS RBI API 510 ASME Sec. VIII Div. 1 and API 510

Where can fatigue cracking typically be first detected? a. b. c. d.

16.

Pressure vessel engineer/organization who is experienced in design An authorized inspector A pressure vessel engineer/organization who is experienced in design and authorized pressure vessel inspector Only the owner-user

The factors of LOF and COF are considered for which methodological evaluation? a. b. c. d.

15.

At crown portion At knuckle portion Mean of (a) and (b) Lower of (a) and (b)

Original construction code of a pressure vessel is ASME Sec. VIII, Div.1. The vessel has corrosion problems and is being evaluated according to ASME Sec. VIII Div. 2. Who should approve the evaluation based on Sec. VIII, Div. 2? a.

14.

If higher corrosion allowance is provided from existing vessel thickness If design pressure is reduced (other factors remaining same) If design temperature is changed (a) and (c)

At points of low-stress intensification such as reinforced nozzles At points of high-stress intensification such as branch connections At points where cyclic stresses are very low At points where there are only the primary stresses

As per ASME Sec. VIII, Div. 1, in pressure testing, if stress ratio = 1, the test pressure as compared to design pressure shall be: a. 1.5 times for hydrotest b. 1.3 times for pneumatic test c. Same for both hydro and pneumatic d. None of the above 161

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17.

As per ASME Sec. VIII, Div. 1, if permanent deformation is observed due to over pressure during hydro testing: a. b.

c.

d. 18.

For a new vessel the corrosion rate will be established based on: a. b. c. d.

19.

Run the vessel for 6 weeks and establish the corrosion rate Run the vessel for 12 weeks and establish the corrosion rate Run the vessel for 18 weeks and establish the corrosion rate A corrosion engineer should be consulted for establishing corrosion rate

A pressure vessel internal inspection frequency can be increased more than 10 years provided RBI evaluation is carried out. It should be approved by? a. b. c. d.

20.

The inspector should ask for re-test using proper test pressure. Follow-up the hydro-testing by a pneumatic test at proper pressure, taking suitable precautions as given in code for pneumatic test. The inspector may ask for providing additional stiffening rings around vessel and carry out re-hydro test at proper test pressure. The inspector may reject the vessel.

Owner user/Jurisdiction Pressure vessel engineer Authorized inspector Pressure vessel engineer & authorized inspector

Identify incorrect statement. a. b. c. d.

ASME Sec. VIII, ASME Sec. VIII, lethal fluids ASME Sec. VIII, ASME Sec. VIII,

Div. 1 may be adopted for unfired steam boilers Div. 1 may be adopted for vessels containing Div. 1 may be used for design of mobile vessel Div. 1 may be used for design of pump casings

21.

Identify incorrect statements. The pressure vessel materials tend to be less brittle: a. As material thickness increases b. As service temperature increases above transition temperature c. a and b d. None of above is a correct statement.

22.

Typical mode of failure in ferrous metals at low temperatures is: a. b. c. d.

Ductile failure Creep failure Fatigue failure Brittle failure 162

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23.

Which of the following is typical phenomenon in low-alloy chromium steels? a. b. c. d.

24.

The term “away from weld” for recalculating the required thickness (Vessels with E<1), means area lying away from weld __________ on either side of the weld or __________ times the minimum measured thickness on either side of the weld, whichever is greater. a. b. c. d.

25.

b. c. d.

2 5 2 5

feet feet meter meter

Minimum PWHT temperature increases with increase of vessel thickness. PWHT Soaking period increases with increasing vessel thickness. Thickness has to be accounted for working out heating and cooling rates. Only (b) and (c) above

Scope of API 510 covers: a. b. c. d.

28.

4 2 2 4

In PWHT of pressure vessels that are built in carbon and low-alloy steels: a.

27.

1”, 1", 2", 2”,

If the part to be PWHT’ed is longer than the furnace, multiple shot PWHT is proposed. What is the minimum over lap as per code to ensure proper PWHT? a. b. c. d.

26.

Creep failure Temper embrittlement Caustic embrittlement Stress corrosion cracking

Nuclear vessels Vessels for human occupancy Power boilers None of these

If there is conflict between API 510 rules and prevailing jurisdictional requirements: a. API 510 shall prevail over jurisdiction requirements. b. Jurisdiction requirements will prevail over API 510 requirements. 163

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c. d. 29.

“On stream-inspection” means inspection carried out: a. b. c. d.

30.

b. c. d.

Owner-user Authorised inspection agency Jurisdiction authority None of the above

For recertification of API 510 authorised inspector, he shall be “Actively engaged” in inspection of pressure vessels during the most recent 3-year period. The term “actively engaged” means: a. b.

c. d.

33.

NDE Level II or Level III person only, as he already possesses requisite knowledge and skill to evaluate and accept NDE results Authorized inspector only Since NDE is specialist job, authorised inspector need not be involved (a) and (c)

As per API 510, responsibility to develop a Quality Assurance Inspection Manual shall rest with: a. b. c. d.

32.

Only when a vessel is in operation Only when a vessel is not in operation From outside and vessel may or may not be in operation “On-stream inspection” is same as “external inspection”

As per API 510, all NDE results for in-service inspection shall be evaluated and accepted by: a.

31.

Depends on authorised inspector, which one to adopt Depends on owner / user, which one to adopt

Minimum of 25% of time shall be spent on inspection activities Minimum of 20% of time shall be spent on inspection activities AND shall cover inspection on at least 75 pressure vessels Minimum of 20% of time shall be spent on inspection activities OR performance of inspection on 75 pressure vessels Performance of inspection on 100 pressure vessels as minimum

Prior to internal inspection, the vessel should be made ready as follows: a. b. c. d.

Drained, purged, gas tested, isolated Isolated, gas tested, drained, purged Gas tested, isolated, drained, purged Isolated, drained, purged, gas tested

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34.

A vessel failure occurred due to repeated stress fluctuations. The failure is called: a. b. c. d.

35.

Fatigue failure of pressure vessels may be caused due to: a. b. c. d.

36.

Creep is aggravated at lower temperature Creep is aggravated at elevated temperatures Creep is aggravated at points of stress concentrations Only (b) an (c)

Choose the incorrect statement. a. b. c. d.

39.

Areas of high secondary stresses (stress concentration) Areas of uniform stress Areas exposed to stagnant flows Only (a) and (b)

Which of the following are characteristics of “creep” in carbon steel? a. b. c. d.

38.

Temperature changes Pressure changes Any of (a) or (b) None of (a) or (b)

Likely areas where fatigue failure may be caused are: a. b. c. d.

37.

Brittle failure Creep failure Fatigue failure Stress corrosion cracking (SCC)

Higher the material ductility, higher is possibility of brittle failure. Carbon and low alloy steels are susceptible to temper embrittlement if operated at sub-zero temperatures. Locations where metals with different thermal coefficients are welded together are susceptible to thermal fatigue. None of the above is correct statement.

For MAWP calculations as per API 510, the thickness as determined by inspection shall be used in these calculations after: a. b. c. d.

Deducting corrosion loss up to next inspection Deducting twice the corrosion loss up to next inspection Use the thickness as it is. As regards thickness reduction due to corrosion, Code does not give specific guidelines.

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40. Temper embrittlement is: a. b. c. d. 41.

b. c. d.

5 2 6 7

stages stages stages stages

In above question what will be the incremental values of pressurization at first and second stage if pneumatic test pressure is 250 psi? a. b. c. d.

45.

1½ times 2½ times 3 times 4 times

A vessel is to be pneumatically pressure tested to 250 psi. This test pressure will be reached in how many stages of pressurization? a. b. c. d.

44.

Work out part MAWP at thinnest patch and that will represent vessel MAWP Vessel MAWP does not get affected by thinning of the vessel Work out part MAWP for lowest head, and that will represent vessel MAWP Lowest value, as worked out by the worst combination of part MAWP and corresponding hydrostatic head at that location

When dial-type indicating and recording pressure gauges are used to monitor leak testing, the maximum gauge range shall not exceed which multiple of the expected test pressure? a. b. c. d.

43.

None of above

Three corrosion patches were seen on the shell for a tall vertical vessel to decide their effect on vessel MAWP: a.

42.

Brittleness due to low temperature operation Brittleness due to Hydrogen Sulphide attack at high temperatures (exceeding 700°F) Loss of ductility in Cr–steels due to incorrect PWHT and High temperature service

125 psi, 25 psi 50 psi, 50 psi 100 psi, 50 psi None of above

For a vessel which was in service, top dished head (2:1 Ellip.) was corroded severely was replaced by a properly designed Hemisph. The head is designed as per the present design conditions of the vessel. This is: 166

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a. b. c. d. 46.

Pneumatic test is proposed for a vessel instead of standard hydro test. Most probable reason for this could be: a. b. c. d.

47.

d.

Loading temperature and heating rate Holding temperature and holding time Cooling rate and un-loading (from furnace) temperature All of the above are important things to be verified

Vessel containing lethal substance with shell thickness of 20mm requires: a. b. c. d.

50.

Spherical segment Conical segment Ellipsoidal segment Knuckle portion

In post weld heat treatment inspection what important things you will verify: a. b. c.

49.

The vessel internal is lined with refractory No water is available The skirt of the vessel is too week to take care of the static water head and pressure. Any one or both of a and c above

Crown portion for both Ellipsoidal and Torispherical heads may be considered to be the ____________ located entirely within a circle whose center coincides with the center of the head and diameter equal to 80% of vessel diameter. a. b. c. d.

48.

A repair An alteration New vessel MAWP will have to be worked out. b and c above

Spot radiography (RT-3) Full length radiography (RT-1) No radiography (RT-4) Penetrant is sufficient if radiography testing is not available

API 510 can be applied to in-service pressure vessels built as per: a. b. c. d.

ASME Section VIII Other international standard Non-standard vessel which may be in operation All of the above

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MID EXAM – Closed Answer Key

Q.

ANS.

1

B

2

REFERENCE

Q.

ANS.

REFERENCE

UG – 116 e-2 and Table UW - 12

26

D

UCS – 56, d1, 5

D

API 510, 4.2.1, 6.1.1

27

D

API 510, App. A

3

B

UG – 77

28

B

API 510, 1.1.3

4

B

API 510, 8.1.6.2.1

29

C

API 510, 5.5.3

5

A

API 510, 5.3

30

B

API 510, 4.2.4

6

B

API –510 , 4.2.4

31

A

API 510, 4.2.1

7

C

ASME VIII, UG – 116

32

C

API 510, App. B 3.2

8

A

ASME VIII, UG - 116

33

D

API 510, 5.3.3

9

D

API 510, 7.4.3

34

C

General Knowledge

10

D

35

C

General Knowledge

11

D

API 510, 5.5.6.3 & Practical Experience API 510, 7.3

36

A

General Knowledge

12

B

API 510, 7.4.6.1

37

D

General Knowledge

13

C

API 510, 8.1.1

38

C

General Knowledge

14

B

API 510, 5.2

39

B

API 510, 7.3.3

15

B

General Knowledge

40

C

API 510, 3.59

16

D

UG – 99 and UG - 100

41

D

ASME VIII, UG – 98 (a)

17

D

UG – 99 (d)

42

D

ASME VIII, UG - 102

18

A

API 510, 7.1.2

43

C

ASME VIII, UG - 100

19

D

API 510 6.3.2

44

A

ASME VIII, UG – 100

20

D

ASME Sec VIII

45

D

Application of API 510, 3.2

21

A

ASME VIII, Fig. UCS – 66

46

D

Application of UG – 100 (a)

22

D

ASME VIII, Fig. UCS – 66

47

A

API 510, 7.4.6

23

B

API 510, 3.5.9

48

D

UCS – 56, d1, 2, 5

24

B

API-510 7.4.5

49

B

ASME UW-11(a)

25

B

ASME VIII, UW – 40 a2

50

D

API 510, 1.1

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MID EXAM - Open Instructions: Choose only one answer which you think is most appropriate. Use the attached attempt sheet in answering the following questions.

1.

A vessel with 50 inches diameter is to be provided Std. torispherical heads. The heads shall be formed with crown radius and min. knuckle radius as follows (head thickness = 1.2 inch): b. c. d. e.

2.

A pressure vessel with nominal diameter 1200 mm was inspected for ovality of shell. A opening of 200 mm I.D. exists. The permissible ovality at the vessel cross section which is 150 mm from center of the opening is: a. b. c. d.

3.

50 inch, 4 inch 50 inch, 3.6 inch 25 inch, 3 inch None of above

12 16 14 18

mm mm mm mm

A pressure vessel has design pressure = 300 psi. Its safe stress values at ambient and designed temperatures are 19,800 psi and 18000 psi respectively. The minimum hydrostatic test pressure and inspection pressure respectively for above will be: a. b. c. d.

450 psi, 390 psi 390 psi, 330 psi 429 psi,330 psi None of the above

4.

A vessel is to be pneumatically pressure tested. What are some of the essential requirements for this test? a. While pressuring, increase the pressure stepwise. b. While pressuring, reach the test pressure without stopping, so that pressure does not fall during pressurisation stage. c. Ensure that test pressure is retained till completion of inspection of all welds using soap sud. d. All of above.

5.

For a Pressure vessel with MDMT = 2 deg. C, is to be hydrostatically tested. The test shall be conducted at a temperature: a. b. c. d.

32°C 32°C 19°C 19°C

to 48°C to 120°C max to 48°C 169

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6.

General “mill under tolerance” according to ASME Sec., VIII Div. 1 for the plates is a. b. c. d.

7.

0.01” or 6% (whichever is smaller) 0.1” or 6% (whichever is smaller) 0.1mm or 6% (whichever is larger) None of the above is a correct statement

Following two combinations of nozzle pipe diameter and shell thickness are to be checked for reinforcement requirements Case 1: Vessel wall thk = 1/2 " and nozzle size 4” N.D. (4-1/2” OD) Case 2: Vessel wall thk = ¾" Nozzle size 2” N.D. (2-3/8” OD) According to ASME Sec. VIII Div 1, separate reinforcement pad calculations must be performed: a. b. c. d.

8.

For both cases For none Calculations required for 1 but not for 2 Calculations required for 2 and not for 1

Check whether Impact testing is required or not for following two plates. Plates are to be used for Storage vessels which will be Hydrotested. Vessels neither do nor undergo temperature / pressure fluctuations or cyclic loading during service. Plate-1: M.O.C. Sa 515 Gr.70, thk=0.5”, MDMT= +10°F Plate-2: M.O.C. Sa 516 Gr.70, thk=1.0” MDMT= - 5°F a. b. c. d.

9.

Both require impact testing. Both do not require impact testing only Plate -1 requires impact testing Only Plate-2 requires impact testing

In establishing a “Mandatory Quality System” manual which of the following need not be included as mandatory requirement? a. b. c.

d.

Organisation and reporting Structure Control system to ensure that only Qualified procedures and welders are employed in repair/ alterations. Control system to ensure that only the qualified NDE personnel and procedures are employed during inspection, repair, alteration Frequency (interval) for Internal and External in-service inspections. 170

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10.

For vessel 0.75 inch thick, MDMT specified was (-45ºF) and material of construction used was SA 516 Gr 60. a. b. c. d.

11.

For the given configuration, reinforcement area available in shell will be: Data: t = 16 mm tr = 15 mm tn = 8 mm d =112 mm b. c. d. e.

12.

13.

1680 mm sq 112 mm sq 224 mm sq None of above

For Reinforcement pad to shell weld, the correct throat dimension required as per ASME Sec. VIII, Div. 1 shall be: a.

½t

b. c.

½ tmin ⅔t

d.

⅔

tmin

The minimum PWHT temperature and minimum holding time for 1.5 inch thick welded joints P no. 5A plates shall be. a. b. c. d.

14.

Specify impact testing of material Impact testing of material need not be specified Specify impact testing of vessel after PWHT Specify impact testing of vessel after fabrication , prior to PWHT.

13000 F, 1.5 hrs. 12500 F, 1.5 hrs 11000 F, 1.5 hours None of above

A standard seamless (E=1) torispherical head (1 inch nom. thk) is to be used for construction of new pressure vessel with 72 inch ID, and design pressure = 300 psig. Material of construction has allowable stress of 20,000 psig. Which of the following statements is most appropriate? (Corrosion allowance is nil.)

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a. b. c. d. 15.

A seamless (E=1) 2:1 Ellipsoidal head 60 inch ID, 400 psi design pressure, (corrosion allowance = 0) and (S = 20000 psig) when new, was provided thickness of 5/8”. Your assessment is: a. b. c. d.

16.

3/32” ¼” 3/16” 1/8”

A seamless shell (1 course) with two seamless elliptical heads are combined to form a vessel. Spot radiography was performed on the attaching type 1 welds. What joint efficiency / quality factor must be used for the head and shell calculations? (Assume circumferential stress governs.) a. b. c. d.

19.

1/16 t 1/8” 3/16” 1/8 t

What is the maximum reinforcement permitted for a 1 inch thick circumferential weld? a. b. c. d.

18.

Head was designed correctly as per ASME Sec. VIII, Div. 1 Head was not designed correctly. Thickness is inadequate. Depends on the opinion of third party inspector None of the above

What is the alignment tolerance of a Category “A” weld joint, where the thinner of the two plates is 1-1/2” thick? a. b. c. d.

17.

Conforms ASME Sec. VIII Div. 1 Does not conform ASME Sec. VIII, Div. 1 Depends on opinion of Vessel engineer Torispherical head is not permitted for use by code

0.90 0.85 1.00 0.70

A rounded indication ¼” diameter was found during spot radiography of a 1/2” thick vessel weld. Your interpretation would be that: a.

The indication is not acceptable to ASME VIII, UW – 51. 172

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b. c. d.

20.

The indication is not acceptable to spot radiography ASME VIII, UW – 52. The rounded indications are not a factor in the acceptability of welds not required to be fully radiographed. The rounded indications are not a factor for fully radiographed welds.

What is the length of a discontinuity permitted in a weld joining 0.575” thick plates when found by the radiographic method (RT – 1) a. b. c. d.

1/3t ¼” ¾” 1/3”

Questions 21 – 24 are from this set of conditions. A 250 psi (Design Pressure) vessel is to be pneumatic tested in accordance with the original ASME Section VIII, Div. 1 rules. The material is SA-516 – 70 and has a design stress of 12,000 psi and stress of 17,500 psi at ambient test temperature. 21.

What is the pneumatic test pressure required? a. b. c. d.

22.

10 10 30 30

degrees degrees degrees degrees

above above above above

operating temperature MDMT MDMT zero

What is the first stage pressure reading of the vessel gauge when pneumatically tested? a. b. c. d.

24.

psi psi psi psi

What is the minimum temperature (°F) at which a fabricated vessel can be tested? a. b. c. d.

23.

455 401 375 313

401 227 187 201

psi psi psi psi

What is the pressure reading when inspection is preformed? a. b. c. d.

401 412 364 318

psi psi psi psi

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25.

ASME Section VIII, Division 1 magnetic particle nondestructive examination personnel shall be qualified in accordance with: a. b. c. d.

Section VIII, Division 1 (Appendix) standards Section IX SNT-TC-1A ASME Code, Section V

MID EXAM – Open Answer Key

Q. NO. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

ANSWER B B C A D A C B D A B B B A A B C C C B B C D C A

REFERENCE ASME VIII, UG – 32 (j) ASME VIII, UG – 80 (a) 2 ASME VIII, UG – 99 (b) and (g) ASME VIII, UG – 100 (d) ASME VIII, UG – 99 (h) ASME VIII, UG – 16 (c) ASME VIII, UG – 36 (c), 3 (a) ASME VIII, UCS – 66 and UG – 20 (f) API 510, 4.2.1 ASME VIII, Fig. UCS - 66 ASME VIII, Fig. UG – 37.1 ASME VIII, UW – 16, ASME VIII, UCS – 56, Table for P5 ASME VIII, UG – 32 (e) ASME VIII, UG – 32 (d) ASME VIII, UW – 33 (a) ASME VIII, UW - 35 ASME VIII, UW – 3 and UW – 12 (d) ASME VIII, UW – 52 c (3) ASME VIII, UW – 51 b (2) a ASME VIII, UG – 100 (b) ASME VIII, UG – 100 (c) ASME VIII, UG – 100 (d) ASME VIII, UG – 100 (d) ASME VIII, App. 6

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POINTS TO RECALL – DAY 10 1.

API 576 provides practical guidelines to meet API 510 requirements for pressure relieving devices (PRDs). It does not cover training requirements.

2.

Inspection of PRDs is essential for: a. b.

3.

Protection of equipments and safety of personnel To determine condition of device itself and its operational characteristics

Inspection frequency: a.

b.

Inspection and shop maintenance — Normal frequency is 5 years (max.) but may be up to 10 years for clean, noncorrosive, non-fouling medium Visual on-line survey — 5 years max.

4.

Safety valve is pop-opening valve, used on gases and vapors. Relief valve is “proportional opening” valve used on liquids. Safety relief valves can function both ways. Back–pressure correction is done on balanced safety relief valves.

5.

After the valve is removed from service, first action is to check its relieving pressure (pop pressure) in the “as received” condition. Subsequently, carry out detailed visual examination, dismantling, cleaning, and lapping of valve seat. Set the pop at desired pressure and confirm the same at least once. Carry out leak test.

6.

Leak test is carried out (at 90% of relieving pressure) by monitoring air bubbles appearing per minute under head of ½” and comparing with acceptance chart.

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API 510- INSERVICE PRESSURE VESSEL INSPECTOR PREPARATORY COURSE

PART VIII

QUESTION BANK QUESTIONS ON API 510 CODE

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Questions on API 510 Code-(2006 Edition). Closed Book SECTION - 1 Q .- 1

API 510 Inspection code applies to : a)

All in service vessels in any industry.

b)

All in service vessels in Petroleum Refinery only.

c)

All in service vessels in Refining and Chemical Process Industries.

d)

In – service vessels as well as for the New construction of vessels.

Ans - (c) - API 510 – 1.1.1 Q.- 2

API 510 can be applied to which of the following in service vessels. a)

Constructed in accordance with an applicable construction code.

b)

Vessels constructed without a construction code.

c)

Non – standard Vessels.

d)

Ale of above

Ans. (d) Q. – 3

API 510 – 1.1.1

For in-Service verses if these is conflict between ASME code and API 510 code. a)

ASME code takes priority as it is basic code for pressure verses.

b)

API 510 code will take priority.

c)

Any one code either ASME or API 510 may be used depending on opinion of Inspector.

d)

ASME may be used if vessel Engineer approves.

Ans - (b) - API 510 – 1.1.1 Q. – 4

Choose correct statement a)

API 510 code is not permitted to be used in conflict with prevailing regulatory requirements.

b)

If requirements of API 510 code are more stringent than requirements of regulation, then API 510 shall govern.

c)

Either API 510 code or regulatory requirements may be used in all cases.

d)

Only API 510 code shall be used in all cases

Ans - (b) API 510 1.1.3

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Q. - 5

Identity the peruse vessels which are excluded from specific requirements of API 510 Inspection code. a)

Pressure vessels on movable structures covered by other jurisdictional requirements.

b)

Pressure vessels fisted for exemption in the scope of applicable construction code.

c)

Both (a) and (b)

d)

Pressure vessels with pressure less than 100 PSI with no Limitation on verse volume.

Ans - (c) - API 510 – 1. 2. 2 Q. - 6

API 510 code recognizes Technical concepts according to : a)

API 579 Fitness for service

b)

API 580 Risk based inspection ( RBI) for determining inspection intervals.

c)

It recognizes neither FFS nor RBI

d)

It recognizes both a) and b)

Ans. - (d) - API 510 – 1.3 Q. -7

Which of the following Recommended Practice covers Inspection of pressure vessels. a) API RP 576

b) API RP 577

c) API RP 572

d) API 510

Ans - (c ) - API 510 Section 2 Q. – 8

Which of the following recommended practice describes the Damage Mechanisms in Retuning Industry. a) API RP 576

b) API RP 577

c) API 572

d) API RP 571

Ans - (d) - API 510 Section 2 Q. – 9

Which of the following recommended practice describes Inspection of Pressure Relieving devices. a) API RP 576

b) API RP 577

c) API RP 572

d) API RP 571

Ans - (a) - API 510 – Section 2 Q.- 10

Which of the following Recommended Practice covers welding Inspection and Mat allergy. a) API RP 576

b) API RP 577

c) API 572

d) API 571

Ans - (b) - API 510 – Section 2 178

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Q. - 11

API Publication 2201 covers. a)

Procedures for hot tapping an equipments in service

b)

Procedures for calibration of Pressure Relief Devices

c)

Procedures for Fitness for service Andy sis

d)

Methodology for RBI Andy sis

Ans - (a ) - API 510 Section -2 Q. - 12

Risk Based Inspection methodology is covered by which of the following documents. a) API RP 579 Ans - (b)

Q. - 13

b) API RP 580

c) API RP 577

d) API RP 571

- API 510 Section 2

Methodology for Fitness for service is covered by which of the following document. a) API RP 579 Ans

b) API RP 580

c) API RP 577

d) API RP 576

- (a) - API 510 Section 2

SECTION – 3 Q. -14

Which of the following is not am " Alteration" a)

Any duplicate replacement

b)

Addition of any reinforced nozzles than or equal to size of existing reinforced nozzles.

c)

Addition of nozzles not requiring re intercommons

d)

All of above

Ans - (d) - API 510 – 3.2 Q. -15

which of following does not constitute the Authorized Inspection Agency a)

Inspection organization of jurisdiction in which pressure vessel in used

b)

Inspection organization of insurance company covering insurance of the pressure vessels.

c)

Inspection department of repair organization

d)

Inspection organization of Owners user.

Ans Q. – 16

- (c) - API 510 - 3.6

Authorized Pressure Vessel inspector shall be a person. a)

Qualified and certified according to requirement of a API 510.

b)

Qualified and certified according CWI requirement of AWS. 179

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c)

Both a) and b)

d)

Qualified and certified according to ASNT requirements.

Ans - (a) Q. - 17

According to API 510, the term " CML" means a)

Condition Monitoring Locations

b)

Corrosion Monitoring Locations

c)

Critical Monitoring Locations

d)

Corrosion Measurement Locations

Ans Q. - 18

API 510 – 3.7

- (a) - API 510 – 3.9

As per API 510, the welding technique used to obtain " Grain refinement and tempering of underlying Heat Affected Zone " is knows as a)

Controlled deposition welding

b)

Controlled – grain welding

c)

Constant Current welding

d)

Constant deposition welding

Ans - (a) - API 510 – 3.11 Q. -19

" Temper Bead " and " Half Bead" Techniques are a)

Typical welding techniques with GTAW Process.

b)

Typical welding techniques with SAW Process.

c)

Typical controlled deposition welding techniques

d)

Typical Repair welding procedures.

Ans - (c) Q. - 20

API 510 – 3.11

An examiner is person who ________ the inspector by performing specific NDE but need not evaluate the results of these examinations ( Pick up the correct word for filling the blank) a)

Supervises

b)

Co- ordinates with

c)

Assists

d)

Directs

Ans - (c) - API 510 – 3.20 Q. - 21

Maximum Gauge Pressure permitted at the top of a pressure versel in its operating position for designated temperatures is called. a)

Maximum operating Pressure 180

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b)

Maximum Design Pressure

c)

Maximum Allowable working pressure

d)

None of above

Ans - (c ) - API 510 – 3.37 Q. - 22

The term " MDMT " means: a)

Maximum Design metal Temperature

b)

Maximum Design Mean temperature

c)

Minimum Design Metal Temperature

d)

Minimum Design Mean Temperature

Ans

Q. - 23

- (c) - API 510 – 3.38

" Work necessary to restore a verse to a condition suitable for sate operation at Design conditions" is called a)

A Repair of Vessels

b)

A Restoration of Vessels

c)

A Renovation of Vessels

d)

A Re- rating of the Vessels

Ans - (a) - API 510 - 3.53 Q. - 24

Any cutting, grinding, welding operation on pressure Vessels not specifically considered as " Alteration" is consided as a)

A Re- rating

b)

A Repair

c)

A Restoration

d)

A Renovation

Ans Q. - 25

(b) - API 510 – 3.53

Which of the following is not a Repair Organization a)

Subcontractor supplying manpower for repair works

b)

Holder of ASME U – stamp

c)

Holder of Valid R – stamp issued by National Board.

d)

A Owner or user of Pressure vessels who repairs his own equipment.

Ans - (a) - API 510 – 3.54 Q. – 26

" A Re – rating " means : a)

Change in Design temperature rating. 181

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b)

Change in MDMT

c)

Change in MAWP Rating

d)

Any one more of (a), (b), (c)

Ans - (d) - API 510 – 3.56 Q. – 27

Which of the following is Not " Testing" according to API 510 a)

Testing such as PT, MT. etc.

b)

Pressure Testing

c)

Notch toughness testing

d)

Mechanical testing such as hardness or strength testing

Ans Q. – 28

- (a) - API 510 – 3.61

Reduction of toughness due to metallurgical change that can occur in some low alloy steels due to long exposure at hight temperatures (above 650 0 F) is knows as : a)

Graphitization

b)

Methane embrittlement.

c)

Temper embrittlement.

d)

None of above

Ans

- (c) - API 510 - 3.59

SECTION – 4 Q. – 29

Who shall exercise overall control of activities relating to In-service Inspection, repair, alteration and Re- rating of pressure vessel. a)

Pressure vessel Engineer

b)

Authorized Inspector

c)

Owner / User

d)

Repair organization.

Ans - (c) - API 510 – 4.1 Q. - 30

Who is responsible for developing, documenting, implernenting, executing and assessing inspection systems and procedures. a)

Owner / User organization

b)

Authorized Inspector

c)

Pressure vessel Engineer

d)

Jurisdiction organization

Ans - (a) - API 510 - 4.2.1 182

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Q. – 31

According to API 510, the responsibility for activities involving design, engineering review or evaluation of pressure verses covered by API 510 Inspection code rests with a)

Authorized Inspector

b)

Corrosion Specialist

c)

Repair organization

d)

Engineer

Ans - (d) - API 510 - 4.2.2 Q. – 32

The Inspector is responsible to ______ to assure that the inspection, NDE and testing activities meet API 510 requirements. a)

Examiner

b)

Owner / User

c)

Engineer

d)

None of above

Ans - (b) - API 510 - 4.2.4

Q – 33

Who is responsible to provide the materials, equipment quality control and workmanship that in necessary to maintain and repair the vessels. a)

Owner – User

b)

Repair organization

c)

Inspector

d)

Examiner

Ans - (b) - API 510 - 4. 2. 3. Q – 34

A person holds Level II certificates in 3 methods of NDT, as well as API 510, certified, He is involved in assuring that Inspection, NDE and Testing activities meet API 510 requirements, all NDE results also are evaluated by him. as per API 510, he is performing duties of : a)

An Examiner

b)

An Inspector

c)

Both Examiner and Inspector

d)

None of above

Ans

- (b) - API 510 - 4. 2. 4.

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SECTION - 5 Q – 35

According to API 510, Inspection plan shall be developed by : a)

An Inspector, in consultation with a corrosion specialist.

b)

An engineer, in consultation with a corrosion specialist.

c)

An Inspector or Engineer

d)

An Inspector and Engineer

Ans - (c) - API 510 - 5.1.1.1 Q – 36

A assessment involving study of both the Probability and the Consequence of failure is called. a) RBI Assessment b) Process Hazard Analysis c) Integrity assessment d) only B) and C) above Ans. - (a) - API 510 - 5.2

Q – 37

RBI assessments shall be updated after : a)

Each Vessel inspections

b)

Each time the process or hardware changes are made that significantly affect damage rates.

c)

either (a)

or (b)

d)

Every 10 Years.

Ans - (c) - API 510 - 5. 2. 4 Q. – 38

Prior to Internal inspection of in-service perverse verses should be. a)

Cleaned gas tested ventilated drained and purged in that order.

b)

Ventilated drained, clamed gas tested and purged in that order.

c)

Drained, purged, cleamed, ventilated and gas tested in that order.

d)

Gas tested, drained, ventilated and cleamed in that order.

Ans - (c) - API 510 - 5. 3. 3 Q. - 39

Before performing any required API 510 inspections inspectors shall review : Design and construction records Prior inspection records Material test reports The WPS / P Q R records. Ans - (b) - API 510 - 5.3.4

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Q. - 40

Which of the following damage mechanisms may lead to surface connected cracking a)

Sulphidation

b)

Sulphide stress corrosion cracking

c)

Hydrogen induced cracking.

d)

Only (b) and (c)

Ans - (b) - API 510 – 5.4.1 According to API 510 Internal inspection is conducted by : Q – 41

a)

It shall be conducted by either inspector or examiner.

b)

It shall be conducted by inspector only.

c)

It may be performed by other qualified persons when acceptable to the inspector.

d)

Only (a) and (c)

Ans - ( b) API 510 – 5.5.2.1. Q – 42

According to API 510, External inspection is conducted by : a)

It shall be conducted by either inspector or examiner.

b)

It shall be conducted by inspector only.

c)

It may be performed by other qualified persons when acceptable to the inspector.

d)

It shall be performed by inspector and corrosion specialist.

Ans - (c) -

API 510 -

5.5.4.1.1

According API 510, On stream inspections conducted by Q – 43

a)

It should be conducted by either inspector or examiner.

b)

It shall be conducted by inspector only.

c)

It may be performed by other qualified persons when acceptable to Examiner.

d)

Either (a) or (c)

Ans - (a) - API 510 - 5.5.3.1 Q – 44

The Primary goal of internal inspection is : a)

To assess process side corrosion damage and plan corrective action.

b)

To observe internal surface condition and assess the surface damage.

c)

To find damage that can not be found by monitoring external CMLS.

d)

Both (a) and (b)

Ans

-

(c) - API 510 - 5.5.2.1 185

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Q – 45

As regards inspection of deposits and linings the inspector. a)

Shall routinely remove deposits and linings from small representative areas to assess, the damage beneath the deposit and linings.

b)

If internal linings are in good condition and no reason to suspect damage, it is not necessary, to remove linings for inspection.

c)

The inspector in consultation with corrosion specialist should determine necessity to remove deposit and lining.

Q – 46

d)

Only (b) and (c)

Ans

-

(d) - API 510 5.5.2.3.

A vessel was inspected by inspector to check for leakage, Hot spots, Vibrations, Expansion allowance etc., while the vessel was still operating. According to API 510. The inspector has typically performed. a)

On – Stream inspection.

b)

External inspection.

c)

It could be either on stream inspection or External inspection.

d)

Routine inspection.

Ans - (b) - API 510 5.5.4.1.2. Q – 47

Weep holes in reinforcement plates should : a)

Be closed to avoid entry of rain water, contaminants etc behind the reinforcement plate which may cause serious corrosion.

b)

Remain open to provide visual evidence of leakage.

c)

Either (a) or (b) accepted.

d)

Weep holes are never provided in reinforcement plates.

Ans - (b) - API 510 5.4.1.2 Q - 48

When short term corrosion rate, changes significantly form the previous identified rate, The inspector should a)

Consult a corrosion specialist to determine cause.

b)

Consult Engineer to determine cause.

c)

Decide next inspection interval and remaining life based on the higher – corrosion rate.

d)

(b) and (c )

Ans - (a) - API 510 5.5.5.3

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Q – 49

For buried vessels, the inspection interval shall be based on corrosion rate information obtained from which of the following methods. a)

During maintenance activity on connecting piping of similar material.

b)

Published data on verses handing same or similar fluid.

c) If corrosion rate can not be determined, on steam determination shall be made after 1000 hours. d)

Only (b) and (c)

Ans Q – 50

CUI inspection shall be considered for carbon and low alloy steel vessels which are externally insulated and operate between. a)

1400 F and 4000 F

b)

250 F and 2500 F

c)

100 F and 3500 F

d)

600 F and 2000 F

Ans Q – 51

(a) - API 510 - 5.5.4.2

- (c)

- API 510 - 5.5.6.1

The CUI usually causes – a)

Localised corrosion with carbon and low alloy streets.

b)

Stress corrosion Cracking with Austenitic S.S.

c)

Both (a) and (b)

d)

None of (a) or (b) are caused due to CUI.

Ans - (c) - API 510 5.6.6.2 Q – 52

For CUI inspection which of the following shall be performed a)

Routinely remove some part of insulation and check to presence of CUI.

b)

Shell thickness measurement done internally at typical CUI problem areas.

c)

If insulation is in good condition and there is not reason to suspect damage behind them, it is not necessary to remove the insulation.

d)

Both (b) and (c )

Ans - (d) - API 510 - 5.5.6.3 Typical CMLS include which of the following. Q– 53

a)

Location for thickness measurement.

b)

Locations for stress corrosion cracking.

c)

Locations for High temperature Hydrogen attack.

d)

All of above.

Ans - (d) API 510 -

5.6.1. 187

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Q – 54

API 510 recommends that CML and examination points should be a)

Permanently recorded

b)

Should be varied at each external inspection so that a better idea about the vessel condition is obtained.

c)

Should be changed at each internal inspection to obtain better idea of vessel condition.

d)

Should be varied at each external as well as internal inspection.

Ans Q – 55

(a) -

API 510 5.6.2.5

A Vessel in subjected to cracking mechanism where some cracks are suspected to propagate upto full Thickeners. The appropriate examination Technique for this carbon steel vessel will be a)

Magnetic particle Examination.

b)

Magnetic particle Examination and Normal beam UT.

c)

Magnetic particle Examination and Pressure testing.

d)

PT, RT and Normal beam UT.

Ans Q – 56

-

- (c) - API 510 - 5.7.1

The appropriate technique for detecting interior surface breaking flows when inspecting from external surface of a vessel, is a)

UT shear wave examination.

b)

Eddy current testing.

c)

PT or MT

d)

Both (b) and (c)

Ans - (a) - PSI 510 5.7.1.2 Q – 57

When there is uncertainty about eh original surface location, the pitted surfaces may be ______________ than they appear visually. a)

Thinner

b)

Thicker

c)

may be either thinner or thicker.

d)

None of above

Ans - (a) Q - 58

- API 510 - 5.7.2.1

After repairs are completed, Pressure test shall be – a)

Always applied

b)

Applied if inspector believes it is necessary

c)

Applied if Engineer believes it is necessary.

d)

Both (b) and (c)

Ans - (b) - APS 510 - 5.8.11

188

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A Hydrostatic Pressure test should be conducted with potable water or steam condensate with chloride concentration less than 50 ppm for vessels made with

Q 59

which of the following ? a)

Carbon steel

b)

Any stainless steel.

c)

Type 300 Series stainless steel.

d)

In all of above cases.

Ans - (c) - API 510 - 5.8.4.2 Q – 60

To minimize risk of brittle fracture, API 510 stipulates that test temperature shall be maintained higher than MDMT (for carbon and Low alloy steel vessels) by :a)

300 F above MDMT for all thicknesses.

b)

100 F above MDMT for thickness of 2 inch or less.

c)

300 F above MDMT for thickness more than 2 inch.

d)

Both (b) and (c )

Ans Q – 61

API 510 - 5.8.6.2.

A Pressure test after alteration is __________ a)

Always required

b)

Never required

c)

Normally required

d)

API 510 does not specify anything about pressure test after alteration.

Ans Q – 62

(d) -

(c) - API 510 -

5.8.1.1

If pressure test is not performed after a major repair or alteration appropriate NDE shall be specified as alternative only after. a)

Engineer has approved.

b)

Inspector has approved.

c)

both (a ) and (b)

d)

NDE can not be substituted for Pr. Test as per ADI 510.

Ans - (c) - API 510 - 5.8.7.1

Q – 63

The document giving guidance on performing the Material Verification Program is given by which document. a)

API 578

b)

API 577 189

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c)

API 576

d)

API 575

Ans - (a) - API 510 - 5.9.1 Q – 64

According to API 510, Crack like flaws and environmental cracking shall be assessed by ____________ a)

Inspector

b)

Engineer

c)

Engineer and/or corrosion specialist

d)

Inspector and/or Engineer

Ans - (c ) – API 510 5.10.3 Q – 65

Flange fasteners should be fully engaged with the nut. Any fastener failing to do so is considered acceptably engaged if lack of complete engagement is – a)

One Thread maximum

b)

One Thread Minimum

c)

Two Thread Maximum

d)

Two Threads Minimum

Ans - (a) - API 510 - 5.11.3

SECTION – 6 Initial field inspection of Pressure Vessels at the time of installation is – Q – 66

a)

Always required

b)

Never required

c)

Depends on opinion of vessel manufacturer

d)

Not required if appropriate documentation like manufacturer's data report answers that vessel complies with the specified design.

Ans - (d) - API 510 6.2.1.2 Q – 67

API 510 mandates that the vessel shall be internally and externally inspected and allowable service conditions and inspection interval shall be established for new service if – a)

Ownership of vessel is changed.

b)

If location of vessel is changed.

c)

If either ownership or location in changed .

d)

If both ownership and location are changed.

Ans - (d) - API 510 - 6.2.2.2. 190

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RBI assessment may allow inspection intervals to Q – 68

a)

Exceed 10 year limit for internal inspection

b)

Exceed 5 year limit for external inspection.

c)

Exceed both (a) and (b)

d)

RBI interval must not exceed (a) and (b).

Ans - (c) - API 510 Q – 69

- 6.3.1

A vessel has remaining life of 24 years. What are maximum inspection intervals for internal and external inspections? a)

12 years internal, 12 years external

b)

10 years internal, 10 years external

c)

12 years internal, 5 years external

d)

10 years internal, 5 years external

Ans - (d) - API 510 - 6.4 and 6.5 Q – 70

A vessel has maximum permitted internal inspection as 7 years and external maximum inspection interval as 5 years. What may be its remaining life a)

10 years

b)

14 years

c)

7 years

d)

20 years

Ans - (b) - API 510 - 6.4 and 6.5 Q – 71

If vessel has remaining life of less than 4 years. Next inspection interval for internal inspection will be a)

2 years

b)

Full remaining life upto maximum of two years.

c)

Half of remaining life

d)

None of above

Ans - (b) - API 510 - 6.5.1.1

Q – 72

A vessel was inspected on Jan. 2000. That time it was determined that the vessel has remaining life of 30 years. Between Jan. 2000 to 2004, It was in active service. From Jan. 2004 to Jan. 2007, Vessel was idled and it was isolated from process fluid and it was purged with inert gas. Vessel will be in active service on Jan. 2007 onwards. According to API 510 when shall the next inspection be scheduled considering maximum permitted interval. Vessel was not subjected to RBI assessment. a)

One half of remaining light from Jan. 200. i.e. Jan. 2015 191

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b)

Maximum 10 years from Jan. 200 i.e. Jan. 2010.

c)

Maximum 10 Years from Jan 2004 i.e. Jan 2014.

d)

on Jan 2013.

Ans - (d) Q. – 73

- API 510 6. 5.1.2

Alternative method for setting inspection interval is MAWP method. Inspection interval is within maximum permitted as long as. (Vessel is not re- rated) and no RBI assessment is done) a)

Projected MAWP of limiting component is greater than Name plate MAWP

b)

Projected MAWP of limiting component is greater than Name plate MAWP plus static head pressure.

c)

10 Years Maximum.

d)

Lower of (b) and (c)

Ans - (d) - API 510 - 6. 5. 1. 3. Q. – 74

For large vessel with differing corrosion zones (multi zone vessels), the next internal inspection interval will be scheduled based on. a)

The zone having highest corrosion rate

b)

The zone with lowest remaining life.

c)

Interval will be same for all zones.

d)

Each zone shall be inspected based on the interval for that zone.

Ans - (d) - API 510 – 6. 5. 3. Q. - 75

The essential requirement for Repair organization for testing of preserve repairing relieving Devices ( PRD) is. a)

The repair personnel must have minimum 3 Years of experience in operation of the PRD s.

b)

The repair organization shall have a fully documented training program for its personnel to ensure they are qualified within the & cope of repairs.

c)

Both (a) and (b) are required.

d)

Repair persons must have minimum 5 Years of testing and repair experience for PRDS.

Ans - (b) - API 510 - 6. 6. 1. 2. Q. – 76

Inspection interval for all PRDS is determined by. a)

Inspector

b)

Engineer 192

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c)

Other qualified persons as per system quality assurance system of owner/ user.

d)

Any of above

Ans - (d) - API - 510 - 6. 6. 2. 1 Q. – 77

If RBI is not conducted, test and inspection interval for PRDS in typical process service shall not exceed. a)

5 Years for typical process service.

b)

10 Years for clean, non- corrosive service

c)

Same as Vessel internal inspection interval

d)

only (a) and (b)

Ans - (d) - API 510 – 6.6.2.2 Q. - 78

Inspection interval for on-stream inspection shall be same as (a)

Internal inspection

(b)

External inspection

(c)

Lower of (a) and (b)

(d)

Higher of (a) and (b)

Ans - (a) - API 510 – 6.5.1.1 Q. - 79

Inspection interval for external inspection shall not exceed (a)

5 year

(b)

Same as internal inspection

(c)

Lesser of (a) and (b)

(d)

Higher of (a) and (b)

Ans - (c) - API 510 – 6.4.1 Q - 80

External inspection in typically _________ inspection while the vessel is _______for above ground vessels ( till appropriate blank ) a)

Visual, in operation

b)

Visual and NDT, in operation

c)

Visual, de-pressurized

d)

Visual and NDT, during shut – down

Ans - (a) - API 510 – 6.4.1 Q - 81

External and internal inspection invals are established by a)

Examiner

b)

Inspector

c) Engineer 193

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d)

Either (b) are (c)

Ans - (a) - API 510 – 6.4.1.1 and 6.5.1.1

SECTION – 7 Q - 82

Long – term Corrosion rate is typically determined a)

Using the most recent thickness reading and one taken earlier in the life of equipment

b)

Using the most recent thickness reading and the oldest thickness reading taken in the life of equipment

c)

Using the most recent thickness reading and one taken earlier at least 10 years before in the life of the equipment.

d)

None of above.

Ans - (a) - API 510 – 7.1.1.1 If there is difference between long term and short-term correction rates, Q - 83

Which one shall be selected. a)

Select the rate that reflects the current conditions.

b)

Use higher of the two rates.

c)

Use average of the two rates.

d)

either (a) or (b) may be used.

Ans - (a) API 510 - 7.1.1.2 Q – 84

A Vessel subject to uniform corrosion has present thickness = 0.8". The required thickness = 0.64". It has remaining life of 20 years. The corrosion rate is a)

80 mpy

b) 0.8 mpy

c) 16 mpy

d) None of these

Ans - (d) - API 510 - 7.2.1 Q - 85

For a vessel for which service conditions are being changed, which of the following is not an accepted method. a)

A corrosion rate may be estimated form owner/user's experience.

b)

Use short–term corrosion rate calculated from previous thickness readings.

c)

Use corrosion rate from published data.

d)

On – stream determination of corrosion rate after 1000 hours of service.

Ans - (b) - API 510 – 7.1.2 194

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Q - 86

For a new vessel to determine Corrosion rate which of the following may be adopted a)

From data collected by the owner / user on vessels operating in same or similar service.

b)

From published data.

c)

From on – stream determination after approximately 1000 hours of service.

d)

Any of above

Ans - (d) - API 510 – 7.1.2. Q. 87

If Remaining corrosion allowance in a vessel is 0.24 inch, and next internal inspection interval from present one is scheduled after 8 years what is the probable corrosion rate? a)

30 mpy

b) 15 mpy

c) 7.5 mpy

d) None of above

Ans - (b) - API 510 – 6.5 and 7.2.1 For MAWP Calculation in corrosive service, what is wall thickness used if Q - 88

actual thickness was = 0.75", and Corrosion loss upto next inspection is 0.05", a)

0.65"

b)

0.70"

c)

0.75"

d)

0.60"

Ans - (a) - API 510 – 7.3.3 Q. 89

For MAWP Calculation for a vessel following data is presented. Actual thickness at present = 0.88 inch. governing corrosion rate = 5 mpy. Next inspection interval (Internal) = 8 years Next inspection interval (External) = 5 years What value of thickeners will be used in MAWP Calculation? a) 0.80" Ans - (a)

Q. 90

b) 0.84" - API

c) 0.83"

d) 0.855"

510 – 7.3.3

MAWP as calculated by using the latest applicable edition of ASME code was 320 psi. Original MAWP was 280 psi. No re – rating was performed. What value of MAWP Should be taken as correct MAWP for the vessel in present condition. a)

Still use original MAWP =

280 psi

b)

Use present MAWP

=

320 psi

c)

Use average MAWP

=

300 psi

d)

Either (a) or (b) may be used.

Ans - (a) - API 510 – 7.3.1 195

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Q. 91

For corroded area of considerable size, the wall thickness may be averaged over which maximum length if vessel I.D = 54 inch. a) 27" Ans -

Q. 92

b) 20" (b)

-

c) 18"

d) 54"

API 510 – 7.4.2.1

For locally thinned area of considerable size, which of the following is to be used as actual thickness (tactual) for calculating Remaining life. a) Use multiple lines and determine which will result in lowest average thickness. use this thickness.

b)

Use always single line approach resulting in the highest average thickness. Use this thickness.

c)

Use thinnest thickeners in corroded area.

d)

Use either (a) or (c)

Ans -

Q. 93

(a) - API 510 - 7.4.2.2

For a vessel with 0.85 as joint efficiency, if vessel surface away from weld is corroded. For joint efficiency should be taken for thickness analysis of corroded area a) 0.85

b) 1.0

Ans - (b) Q. 94

c) 0.9

d) use either (a) or (b)

- API 510 – 7.4.5

If corrosion occurs on both sides of a weld in a vessel with required thickness = 2 inch. Which area will be considered area at the weld? a)

Area on either side within 2" form toe of weld

b)

Area on either side within 4" form toe of the weld

c)

Area on either side of the weld within 2" from center line of weld

d)

Area on either side of the weld within 4" from centre line of weld

Ans - (b) Q. 95

- API 510 – 7.4.5

For calculating required thickness at corroded areas for Elliptical and Torispherical heads which of the flouring in used. a)

Use head formula in construction code for entire head

b)

Use head formula in construction code for knuckle portion.

c)

Use Hemispherical head formula in construction code for central portion.

d)

Use both (b) and (c)

Ans - (d) - API 510 – 7.4.6.1

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Q. 96

For Hemispherical and Torispherical head, the central portion of head is defined as the centre of head with diameter equal to what parentages of shell diameter? a)

80 % for both heads

b)

80 % for Torispherical and 90% for ellipsoidal

c)

80 % for ellipsoidal and 90% for Torispherical

a)

90% for both heads.

Ans - (a) Q. 97

- API 510 - 7.4.6.1

For Pressure vessels that have no name plate or no design and construction documentation which of the following may be used to verify operating integrity. a)

Use allowable stress of SA - 283 Gr C if material of vessel is unknown.

b)

Use joint factor of 0.7 for butt welds

c)

Use stress values from current ASME code for any vessel designed earlier than 1999.

d)

both (a) and (b)

Ans - (d) - API 510 - 7.7 Pressure vessel record shall contain four types of records which of the Q .98

following is not part of records. a)

Construction and Design information

b)

Inspection history

c)

Fitness for service records

d)

Certification record of API 510 inspector

Ans - (a) Q. 99

- API 510 - 7.8.2

For Calculation of thickness for central portion of 2:1 Ellipsoidal head, what thickness formula shall be used a)

Hemispherical head formula

b)

Ellipsoidal head formula

c)

Shell thickness formula

d)

Torispherical head formula

Ans Q.100

(a)

- API 510 - 7.4.6.1

If O.D. of shell for a vessel is 60". What value of radius will be used in formula for central portion of the Torispherical head, As per API 510 ? a)

Use 60 " radius and use Hemispherical head formula 197

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b)

Use 54" radius and use torispherical head formula

c)

Use 30" radius and use Hemispherical head formula

d)

Use 54" radius and we hemispherical head formula

Ans - (a) Q .101

- API 510 - 7.4.6.2

If I.D. of a vessel is 60", what value of radius shall be used and what formula shall be used for calculating thickness for central portion of a Ellipsoidal head. The head is 2 : 1 Ellipsoidal. a)

Use 60" and use Ellipsoidal head formula.

b)

Use 54", and use Ellipsoidal head formula.

c)

Use 60', and use Hemispherical head formula.

d)

Use 54", and use Hemispherical head formula.

Ans - (a)

- API 510 - 7.4.6.3

SECTION - 8 For which of the following works authorization from both Inspector and Q .102

Engineer is required? a)

Repairs on vessels complying with ASME – sec VIII Div 1

b)

Alterations on vessels complying with ASME Sec. VIII Div 2

c)

Alterations on vessels complying with ASME Sec. VIII Div 1

d)

(b) and (c) Both

Ans - (d) - API 510 - 8.1.1 Q. 103

For which of the following works authorization form Engineer is not mandatory? a)

Repairs on vessels complying with ASME Sec. VIII Div.2

b)

Repairs on vessels complying with ASME Sec. VIII Div.1

c)

Alterations on vessels complying with ASME Sec. VIII Div.2.

d)

Both (a) and (b)

Ans - (b) - API 510 - 8.1.1 Q.104

Inspector may give prior general authorization for repairs under which conditions? a)

Repairs are limited or routine type on specific vessel

b)

Inspector is satisfied with competency of repairs organization

c)

Repairs will not require pressure test 198

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d)

All of above

Ans - (d) - API 510 - 8.1.1 Q.105

Before any repairs or alterations are performed all proposed methods of design, execution, material procedures NDE and testing for which of the following requires whose approved. a)

Repairs must be approved by Inspector

b)

Alterations must be approved by an engineer

c)

Both (a) and (b)

d)

Inspector and Engineer both must approve the repair and alteration

Ans - (c) Q.106

- API 510 - 8.1.2

All specified repair or alteration work at the designated hold points and after completion of the work must be approved by a)

Repairs to be approved by Inspector

b)

Alterations to be approved by engineer

c)

Both (a) and (b)

d)

Both repairs and alterations shall be approved by Inspector.

Ans

- (d) - API 510 - 8.1.2.2

All nozzle installations on existing vessel shall be approved by Q.107

a)

Inspector

b)

Engineer

c)

Examiner

d)

All of above

Ans Q.108

- (b) - API 510 - 8.1.3

Carbon and alloy steel materials used for welded repairs and alterations must have Carbon content __________ a)

Less than or equal to 0.35%

b)

Above 0.35%

c)

Above 0.25%

d)

less than or equal to 0.25%

Ans - (a) - API 510 - 8.1.4

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Q.109

Temporary repairs may remain in place for longer period beyond the next maintenance opportunity if ____ a)

Evaluated, approved and documented by inspector.

b)

Evaluated, approved and documented by Engineer.

c)

Evaluated, approved and documented by Engineer and inspector

d)

Either (a) or (b) is ok.

Ans Q.110

(c)

- API 510 - 8.1.5.1.1

Fillet weld patches may be used to make _______ a)

Temporary repairs

b)

Permanent repairs

c)

Both temporary and permanent

d)

Fillet patches are not permitted for any type of repair

Ans - (a) - API 510 - 8.1.5.1.2.1 Q.111

Fillet weld patches may be used for temporary repairs but they a)

shall be approved by inspector and engineer

b)

May be subject to acceptance by the jurisdiction

c)

Both (a) and (b)

d)

Must be acceptable to examiner in addition to inspector and engineer.

Ans - (c) - API 510 – 8.1.5.1.2.2. Q.112

A situation has arised where in a new fillet welded patch has to be installed on top of an existing fillet welded patch. it is_______ a)

Permitted if new fillet patch is approved by inspector and engineer.

b)

Permitted if fillet welds are 100% PT or MT examined

c)

Never permitted

d)

Both (a) and (b)

Ans Q.113

-

(c) - API 510 - 8.1.5.1.2.3

Non penetrating nozzles are used as ______ a)

Temporary repairs only

b)

May be permanent repairs for other than cracks.

c)

May be permanent repairs for defects including cracks

d)

only (a) and (c)

Ans - (b) - API 510 – 8.1.5.1.4

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Q.114

Which of the following may not be considered as permanent repair? a)

Excavation of defect and repair welding of excavation.

b)

Weld overlay of corroded area.

c)

Adding strip lining to interior surface

d)

Installing suitably designed fillet patch with 1" rounded corner.

Ans - (c) - API 510 – 8.1.5.1.2.1. Q.115

Fillet welded patches may not be used for repair of crocks unless. a)

The inspector determines that cracks will not be expected to propogate form under the patch.

b)

The fillet patches are acceptable to examiner.

c)

The Engineer determines that cracks will not be expected to propogate form under the patch.

d)

All of above.

Ans - (c) Q.116

API 510 - 8.1.5.1.2.1

Repairing a crack at discontinuity where stress concentrations are high require prior consultation with a)

Engineer

b)

Inspector

c)

Examiner

d)

All of above

Ans - (a) Q.117

- API 510

- 8.1.5.2.1

Insert plate shall meet which of the following requirement? a)

Full penetration groove welds must be provided

b)

May be welded with fillet welds which are 100% PT or MT examined

c)

May be welded with partial penetration butt welds if butt welds are 100% RT examined.

d) Ans Q.118

Both (b) and (c) -

(a)

- API 510 – 8.1. 5. 2. 2

For Overlay repairs, if filler metal having lower tensile strength than base metal is to be used, API 510 stipulates that ___ a)

Repair thickness shall not be more than 50% of required thickeners of base metal.

b)

Repair thickness may exceed 50% if overlay area is 100%

RT or UT 201

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checked to ensure there are no detects c)

Both (a) and (b)

d)

Use of lower strength filler metal is not permitted

Ans Q.119

-

(a) - API 510 – 8.1.5.3.2

Vessels with S. S. Cladding the repair produce shall be reviewed and approved by a)

Inspector

b)

Engineer

c)

Both (a) and (b) above

d)

By Inspector, Engineer and Examiner

Ans - (c) - API 510 - 8.1.5.4.1 Q.120

For repair to S.S. cladding in Cladding vessels if vessel was exposed to atomic Hydrogen migration same far for to be considered in developing repair plan are: a)

Out gasing base metal and PWHT requirement

b)

Age of the vessel

c)

Both (a) and (b)

(d)

None of (a) and (b)

Ans - (a) - API 510 - 8.1.5.4.3 Q.121

While making on – stream welds the reference document giving the guidelines to make on – stream welds is: a)

API 2201

b)

API 572

c)

NACE MR 0175

d)

API 577

Ans - (a) - API 510

- 8. 1.6.1

According to API 510, The ____ shall maintain the records of welding Q.122

procedures and performance qualifications and these records shall be available to ____ before the start of welding (fill up appropriate blanks) a)

Owner /User, client

b)

Repair organization, Inspector

c)

Engineer, Repair organization

d)

Engineer, inspector

Ans -

(b) - API 510 – 8.1.6.2.2

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Q.123

Guidance on how to review the weld procedures and performance Qualifications and how to respond to welding non – conformances is provided by a)

API 577

b)

ASME Sec. IX

c)

API 1104

d)

None of above

Ans Q. 124

(a)

- API 510 – 8.1.6.2.3

If alternative PWHT method is used (Preheat method or Controlled deposition method) the joint efficiency factor. a)

Must be adjusted suitably

b)

May be continued

c)

Fully radiograph repair welds and use efficiency factor = 1

d)

Only (a) and (c)

Ans - (b) - API 510 - 8.1.6.4.2.1.4 Q.125

Pre heat method in lieu of PWHT can not be used for which of the following welding process. a)

SMAW

b)

SAW

c)

GTAW

d)

GMAW

Ans - (b) Q.126

- API 510 - 8.1.6.4.2.2.1

Controlled deposition welding method is used in lieu of PWHT for which of the following a)

When Notch toughness testing is not required

b)

When Notch tougher testing in required

c)

In both (a) and (b)

d)

None of (a) and (b)

Ans - (b)

Q. 127

- API 510 -8.1.6.4.2.3

If the vessel required certain radiography according of construction code, them new repair butt welds shall be a)

100% radiographed irrespective of construction code requirement.

b)

Spot radiographed irrespective of construction code.

c)

Radiographed in accordance with construction code.

d)

Always UT checked.

Ans - (c)

- API 510 - 8.1.7.3

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Q.128

Guidance on NDE of weld joints and weldments is provided by a)

ASME Sec V

b)

ASME Sec VIII

c)

API 577

d)

ASME Sec IX

Ans - (c) Q.129

- API 510 – 8.1.7.1

AS per API 510 for the vessels, the ratings shall be performed in accordance with requirements of: a)

Vessels original construction code only

b)

As alternative API 510 allows re-rating using latest edition of construction code.

c)

Re-rating as per latest edition is permitted only for vessels which are not older than 5 years

d)

Both (b) and (c)

Ans - (b) - API 510 - 8.2.1 Q.130

For Recertification purpose, as per API 510 "Actively engaged as inspector " is defined as which of the following a)

Minimum of 20% of time spent on performing or supervision of inspection activities as per API 510

b)

Performance of or supervision of inspection activities on 75 pressure vessels.

c)

Either (a) or (b)

d)

Both (a) and (b) are required

Ans - (c) - API 510 – B .3.2 Q.131

Actively engaged inspectors shall demonstrate knowledge of revisions to API 510 ____ a)

Once every other certification period (every Six years)

b)

One every Nine years

c)

At the time of each recertification (every there years)

d)

There is no such requirement

Ans - (a) API 150 – B. 3.3

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Question on API 510 Code - (2006 Edition). OPEN BOOK QUESTION BANK – OPEN BOOK 1. Which of the following vessels may be excluded from the application of API 510 Code? A. B. C. D.

Volume= 5 FT3 and Design Pressure= 250 psi Volume= 4 FT3 and Design Pressure= 350 psi Volume= 6 FT3 and Design Pressure= 50 psi Only A & B.

2. Which of the following will form part of Quality System Manual for Inspection / Repairs? A. Organization & reporting structure for inspection personnel B. Original design calculations of the vessel C. Controls necessary that only qualified NDE personnel and procedures are utilized D. Only A & C. 3. From which of the following methods, the corrosion rate information may be obtained for the buried vessels? A. from vessels in similar circumstances B. during maintenance activities on connecting piping of similar material C. by conducting soil resistivity tests of the soil around the buried vessel D. only A & B. 4. Two identical vessels have MAWP= 200 psi. Design Temp= 400 Deg F. They are made of same material specifications. The only difference was vessel 1 was constructed in year 1996 & vessel 2 was constructed in year 2002 as per applicable editions and addenda of ASME Sec VIII Div 1 Code. What will be the correct hydrotest pressure for vessel 1 & vessel 2 respectively, if test temperature for both is same? A. B. C. D.

260 psi & 300 psi 300 psi for both 300 psi & 260 psi 260 psi for both.

5. At the discretion of the inspector, the on-stream inspection may be substituted for internal inspection. Which of the following are some of the conditions for doing so?

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A. B. C. D.

General corrosion rate is less that 5 MPY. Vessel Remaining Life is more than 10 years. Vessel must have internal strip lining or plate lining. Only B & C.

6. A vessel was inspected periodically as per following schedule and thickness results were as following: Year 1990 January : ( Installation time) = 0.8” Year 2000 January : = 0.7” Year 2005 January : ( Present) = 0.62” The long term & short term corrosion rates are are : A. B. C. D.

Long term : 10 MPY, Short Term : 20 MPY Long term : 5 MPY, Short Term : 10 MPY Long term : 12 MPY, Short Term : 8 MPY Long term : 12 MPY, Short Term : 16 MPY

7. In the above question, if the process from the year 2000 remains unchanged and the same will be continued further, what will be the selected corrosion rate and remaining life, if minimum required thickness is 0.46”? A. B. C. D.

10 mpy; 16 years 16 mpy; 10 years 5 mpy; 32 years 12 mpy; 13.3 years

8. When the next internal & external inspections can be scheduled for the above vessel? A. B. C. D.

Internal : January 2013; External : January 2010 Both in January 2010 Internal : January 2010; External : January 2008 Both in January 2013.

9. For a pressure vessel the corrosion rate estimated for the present condition was 4 mpy. Corrosion loss up-to the next internal inspection is estimated as 28 mpy.If the vessel has sufficient corrosion allowance, what is its remaining life? A. B. C. D.

7 Years 14 Years 21 Years 3.5 Years

10. What is the required thickness of the above vessel is the present thickness is 0.766”? 206

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A. B. C. D.

0.710” 0.738” 0.700” 0.720”

11. A Pressure vessel has present thickness of 0.9”. The estimated corrosion rate is 5 mpy. Its next internal inspection is scheduled after 8 years. What thickness value should be used for MAWP Calculations? A. B. C. D.

0.86” 0.82” Higher of A & B None of A & B.

12. What is the length of corrosion averaging for evaluation of locally thinned area of a horizontal vessel if vessel inside diameter is 72 inches? A. B. C. D.

20 Inches 36 Inches 40 Inches 24 Inches

13. A pressure vessel has joint efficiency= 0.85. A corroded area was observed lying away from weld. Which of the following may be done for evaluation of this area? A. Calculate the required thickness of corroded area considering E=0.85 B. Calculate the required thickness of corroded area considering E=1.00 C. Calculate the required thickness of surface at the weld considering E=1.00 D. None of the above. 14. A cluster of three pits had total area of 6 square inches. It can be enclosed in a circle of 7 inch diameter. The required thickness of the vessel is 1.2 inches. Thickness at the bottom of deepest pit is 0.8 inch. The three pits have diameter of 1”, 0.7” 0.8” and their centers are along a straight line. Assuming NIL corrosion allowance, what is your assessment? A. The pits can be ignored. B. The pits can not be ignored since the sum of pits dimensions along the straight line is greater than acceptable value. C. The pits can not be ignored as total area of the pits is greater than the acceptable value. 207

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D. The pits can not be ignored as depth of pits is more than acceptable value. 15. In the question above, if the pits are located in a such a way that only two pits are on a straight line drawn within the circle. What is your assessment? A. The pits are still unacceptable as the depth of the pits is unacceptable. B. The pits are still unacceptable since the total area of the pits is more than the acceptable value. C. The pits can be ignored. D. The pits are still unacceptable since the sum of pit dimensions along straight line is more than the acceptable value.

16. A vessel has required thickness=1.5”. What will be called as “surface at the weld” according to the API 510 for joint efficiency adjustment calculations, when loss of thickness is to be evaluated? A. B. C. D.

2” on either side of the weld, measured from the toe of the weld.. 1” on either side of the weld, measured from the toe of the weld 3” on either side of the weld, measured from the toe of the weld 3” on either side of the weld, measured from the centre of the weld

17. For vessel head analysis as per API 510, what portion is called as central portion of the dished head? A. Central Portion of the head with diameter equal to 80% of shell diameter for Ellipsoidal head only. B. Central Portion of the head with diameter equal to 80% of shell diameter for Torispherical head only C. Both A & B. D. Central Portion of the head with diameter equal to 90% of shell diameter for Ellipsoidal & Torispherical heads, both. 18. A vessel with Torispherical heads has shell OD=50”. For calculating thickness of central portion, what radius shall be used in Hemispherical head formula? A. 50” B. 40” C. 45” D. 25” 19. A vessel with 2:1 Ellipsoidal heads has shell OD=40”. For calculating thickness of central portion, what radius shall be used in Hemispherical head formula? 208

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A. B. C. D.

40” 36” 20” 32”

20. If material specification is unknown for alloy steels, the allowable stress can be taken as the allowable stress of A. SA 283 Gr C Material B. Perform X Ray Fluorecence Analysis and then use allowable stress of SA 283 Gr C C. Perform X Ray Fluorecence Analysis and decide the type of material on which to base the allowable stress D. Always use allowable stress values from the current ASME Code 21. When installing a fillet weld patch adjacent to an existing fillet weld patch ( for a vessel with 72” inside diameter and actual thickness at repair area =1”) what shall be the minimum distance between the toes of fillet welds? A. B. C. D.

12” 6” 18” 24’

22. A full encirclement lap band repair is permitted by API 510. Some of the requirements for this are: A. Design is approved by the inspector & Engineer B. Repair sleeve must cover the complete crack in the weld sleeve C. Use joint Efficiency of 0.45 for longitudinal welds in the repair band D. Only A & C. 23. For SS Clad vessels with base materials belonging to P Nos. 3, 4 & 5 should be examined for cracking by: A. B. C. D.

UT, conducted as soon as repairs are completed. UT, conducted after a delay of at-least 24 hours after repairs RT, conducted after a delay of at-least 48 hours after repairs. PT or MT, conducted after a delay of at-least 48 hours after repairs.

24. Pre-heat, as an alternative to PWHT is permitted in API 510 under certain conditions. Some of the conditions to perform this are: A. Preheat Temp shall be 300 Deg F minimum B. Inter-pass Temp shall be 600 Deg F minimum 209

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C. Preheat & Inter-pass Temp should be maintained at a distance of 4” or 4 times the depth of repaired weld D. All of the above.

25. As an alternative to PWHT, controlled Deposition method is acceptable as per API 510 under certain conditions. Some of the conditions to perform this are: A. Materials shall be limited to P Nos. 1, 3, 4 & 5. B. Welding shall be limited to SMAW, GMAW & SAW Processes. C. Welding technique shall be temper bead or half bead technique. D. All of the above.

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API 510 Preparatory Review Exam 5 –Open Book (Answers Keys) QUESTIONS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

ANSWERS A D D C D D B B B A B D B B C B C A B A D D B D C

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API 510 Preparatory Review Exam 1 –Closed Book 1)

In a 30 mm thick cylindrical shell, the longitudinal as well as circumferential joints are double welded butt welds with full penetration. Which of the following is true as regards the longitudinal and circumferential joints? a) b) c) d)

2)

In question above, the longitudinal welds can be described as a) b) c) d)

3)

Type A, Category 1 Type B, Category 2 Type B, Category 1 None of the above

Type C welds Category C welds Type D welds Category D welds

The welds joining Hemispherical head to shell are described as a) c)

6)

1 2 1 2

All the welds joining nozzle to the shell can be described as a) b) c) d)

5)

Category A, Type Category B, Type Type A, Category Type B, Category

The circumferential welds in the question above can be described as: a) b) c) d)

4)

They are of same category but different types They are of same type but different categories Both the category as well as type are same Both the category as well as type are different.

Type A welds Category A welds

b) d)

Type 1 welds Category 1 welds

Identify correct statement from following options. The nozzle neck to flange weld in a flanged nozzle is category C weld if it is

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a) b) c) d) 7)

Identify correct statement. If vessel longitudinal and circumferential welds are type 1 and spot radiographed only, then stamping on name plate will be: a)

8)

RT1 RT4

b)

RT2

c)

RT3

RT1 RT4

b)

RT2

c)

RT3

d)

For a vessel constructed with Type 1 welds: a) b) c) d)

RT3 means E = 1 RT2 means E = 0.85 RT1 and RT2 may mean E = 1 RT4 means spot radiography

10)

Vessel MAWP for tall vertical vessel will normally be: a) Greater than vessel part MAWPs b) Lower than Vessel part MAWPs c) May be (a) or (b) depending on Vessel height d) Is always same as vessel design pressure

11)

Vessel MAWP of existing vessel will be affected: a) b) c) d)

12)

d)

In the above question, if welds were fully radiographed for their entire length, the stamping on name plate will change to: a)

9)

Nozzle neck to SORF flange weld only Nozzle neck to WNRF flange weld only Both (a) and (b) are category C welds None of (a) or (b) are category C welds

if higher corrosion allowance is provided from existing vessel if design pressure is reduced l (other factors remaining same) if design temperature is changed (a) and (c)

The code design formula for a Torispherical head as per ASME Section VIII Div. 1 actually gives the thickness required: a) c)

At crown portion Higher of (a) and (b)

b) d)

At knuckle portion Lower of (a) and (b) 213

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13)

The hydrostatic pressure caused by 30 ft of liquid column (sp. gr. = 1) will be: a) b) c) d)

14)

Hydrostatic pressure test of vessels may be replaced by pneumatic test a) b) c) d)

15)

220 250 200 260

psi psi psi psi

As per ASME Sec. VIII Div 1, in pressure testing, if stress ratio = 1, the test pressure as compared to design pressure shall be: a) b) c) d)

17)

At the option of vessel manufacturer At the option of vessel inspector Permitted only if water is not available in the region and client (or owner) approves Permitted only if design or operating conditions do not permit use of water as test medium.

What will be the minimum inspection pressure if Pneumatic testing was carried out at 275 psig. as per code a) b) c) d)

16)

10 psi 43.3 psi 4.33 psi None of the above

1.5 times for hydrotest 1.3 times for pneumatic test Same for both hydro and pneumatic None of the above

As per ASME Sec. VIII Div. 1, if permanent deformation is observed due to over pressure during hydrotesting, a) b)

c)

d)

The inspector should ask for re-test using proper test pressure and new pressure gauges. Follow-up the hydro-testing by a pneumatic test at proper pressure, taking suitable precautions as given in code. The inspector may ask for providing additional stiffening rings around vessel and carry out re-hydro test at proper test pressure. The inspector may reject the vessel. 214

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18)

For external pressure calculations, the value of E to be used is worked out on the basis of a) b) c) d)

19)

In external pressure calculations for cylindrical shell, the Factor – A, depends on: a) b) c) d)

20)

O.D. and thickness of shell Design temperature Safe stress value ‘S’ of material All of the above.

Identify incorrect statement. a) b) c) d)

21)

E = 1 for full radiography E = 0.85 for spot radiography E = 0.7 for no radiography E is modulus of elasticity and does not depend on radiography

ASME Sec. VIII Div. 1 may be used for unfired steam boilers ASME Sec. VIII Div. 1 may be used for construction of vessels containing lethal fluids ASME Sec. VIII Div. 1 may be used for design of mobile vessel ASME Sec. VIII Div. 1 may be used for design of pump casings

Identify correct statements. The pressure vessel materials tend to be less brittle: a) As material thickness increases b) As service temperature increases above temperature c) a and b d) None of above is correct a statement.

22)

transition

Typical mode of failure jn ferrous metals at low temperatures is: a) c)

Ductile failure Fatigue failure

b) d)

Creep failure Brittle failure

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23)

Which of the following is typical phenomenon in low-alloy chromium steels? a) c)

24)

b) c) d)

Minimum PWHT temperature increases with increase of vessel thickness PWHT time increases with increasing vessel thickness Thickness has no effect on stipulated minimum PWHT temperature and time Only (a) and (b) above

Scope of API 510 covers: a) b) c) d)

28)

All butt welds in vessel All butt and fillet welds in vessel For closing seams only The code does not permit use of U.T. at all

In PWHT of pressure vessels that are built in carbon steels: a)

27)

Graphitization Stress corrosion cracking Carbide formation and carbide cracking Tamper embrittlement

ASME Sec. VIII Div. 1 recommends use of U.T. in place of R.T. (for a fully radiographed vessel) for: a) b) c) d)

26)

Tamper embrittlement Stress corrosion cracking

Which of the following is typical phenomenon in Silicon steels at elevated temperatures above 700 deg. F? a) b) c) d)

25)

Creep failure b) Caustic embrittlement d)

Pressure vessels mounted on mobile tankers Vessels for human occupancy Pressure vessels installed in ocean-going ships None of the above

If there is conflict between API 510 rules and prevailing jurisdictional requirements: a) API 510 shall prevail over jurisdiction requirements b) Jurisdiction requirements will prevail over API 510 requirements c) Depends on authorized inspector, which one to adopt d) Depends on owner / user, which one to adopt 216

IET/CH/TP/002-R2, Sept. 11

29)

“On stream-inspection” means inspection carried out: a) Only when a vessel is in operation b) Only when a vessel is not in operation c) From outside and vessel may or may not be in operation d) “On-stream inspection” is same as “External inspection”

30)

As per API 510, all NDE results for in-service inspection shall be evaluated and accepted by: a)

b) c) d) 31)

As per API 510, responsibility to develop a Quality Assurance Inspection Manual shall rest with: a) c)

32)

Owner-user Jurisdiction Authority

b) Authorised Inspection Agency d) None of the above

For rectification of API 510 Authorised Inspector, he shall be “Actively engaged” in inspection of pressure vessels during the most recent 3-year period. The term “Actively Engaged” means: a) b)

c)

d)

33)

NDE Level II or Level III person only, as he already possesses requisite knowledge and skill to evaluate and accept NDE results Authorized inspector only Since NDE is specialist job, authorised inspector need not be involved (a) and (c)

Minimum of 50 % of time shall be spent on inspection activities Minimum of 20 % of time shall be spent on inspection activities AND shall cover inspection on at least 75 pressure vessels Minimum of 20 % of time shall be spent on inspection activities OR performance of inspection on 75 pressure vessels Performance of inspection on 100 pressure vessels as minimum

Prior to internal inspection, the vessel should be made ready as follows: a) b) c) d)

Drained, purged, gas tested, isolated Isolated, gas tested, drained, purged Gas tested, isolated, drained, purged Isolated, drained, purged, gas tested 217

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34)

A vessel failure occurred due to repeated stress fluctuations. The failure is called: a) b) c) d)

35)

Fatigue failure of pressure vessels may be caused due to: a) b) c) d)

36)

b) c) d)

Creep is aggravated at lower temperature (say atmospheric temperature) Creep is aggravated at higher temperatures (> 400oC) Creep is aggravated at points of stress concentrations only (b) an (c)

Choose correct statement. a) b) c)

d) 39)

Areas of secondary stresses (stress concentration) Areas of stress reversals Areas exposed to stagnant flows Only (a) and (b)

Which of the following are characteristics of “creep” in carbon steel: a)

38)

Temperature changes Pressure changes Any of (a) or (b) None of (a) or (b)

Likely areas where Fatigue failure may be caused are: a) b) c) d)

37)

Brittle failure Creep failure Fatigue failure Stress corrosion cracking (SCC)

Higher the material ductility, higher is possibility of brittle failure Carbon and low alloy steels are susceptible to temper embrittlement if operated at sub-zero temperatures Locations where metals with different thermal coefficients are welded together are susceptible to thermal fatigue None of the above is correct statement.

For MAWP calculations as per API 510, as determined by inspection shall be used after: a)

Deducting corrosion loss up to next inspection 218

IET/CH/TP/002-R2, Sept. 11

b) c) d)

40)

One of the best methods to determine uniform loss of metal and consequent thickness reduction is: a) b) c) d)

41)

Deducting twice the corrosion loss up to next inspection Use the thickness as it is. As regards thickness reduction due to corrosion, Code does not give specific guidelines.

Radiography Ultrasonic thickness check Magnetic particle testing Visual inspection

Three corrosion patches were seen on the shell below liquid level for a tall vertical vessel to decide their effect on vessel MAWP: a) b) c) d)

Work out part MAWP at thinnest patch and that will represent vessel MAWP Vessel MAWP does not get affected by thinning of the vessel Work out part MAWP for lowest head, and that will represent vessel MAWP Lowest value, worked out the worst combination of part MAWP and hydrostatic pressure at that location

219

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API 510 Preparatory Review Exam 1 –Closed Book Answer Key Q. NO. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

ANSWER B A D D C C C A C B D B D D B D D D A D B

Q. NO. 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41

ANSWER D B A C B D B C B A C D C C D D C B B D

220

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API 510 Preparatory Review Exam 2 –Closed Book 1) API 510 __________ be used as a substitute for the original construction requirements governing a piping system before it is placed in-service. a)

shall not

b)

should

c)

may

d)

can

2) The __________ shall be responsible to the owner-user for determining that the requirements of API 510 for inspection, examination, and testing are met. a)

Vessel Engineer

b)

Authorised Inspector

c)

Repair Organisation

d)

Operating Personnel

3) Who is ultimately responsible for the control of vessel system inspection programs, inspection frequencies and maintenance of all inspection records ? a)

Authorised Inspector

b)

Owner-user

c)

Jurisdiction

d)

Contractor

4) Vessels that are known to have a remaining life of over __________ years or that are protected against external corrosion need not have insulation removed for the periodic external inspection a)

10

b)

15

c)

5

d)

20

5) You have a new vessel that has just been installed. It is completely new and no information exists to establish a corrosion rate. Also, information is no available on a similar system. You decide to put the system in service and NDT it later to determine the corrosion rate. How long do you allow the system to stay in service before you take your first thickness readings ? a)

500 hours

b)

3 months

c) 1000 hours d)

12 months

6) After an inspection interval is completed and if calculations indicate that an inaccurate rate of corrosion has been assumed initially, how do you determine the corrosion rate for the next inspection period ? a)

Check the original calculations to find out what the error is in the original assumption. 221

IET/CH/TP/002-R2, Sept. 11

b)

Unless the corrosion rate is changed by Jurisdiction, the initial rates shall be used.

c)

The corrosion rate shall be adjusted to agree with the actual rate found.

d)

Call in a corrosion specialist.

7) If a vesselis made up of unknown materials and computations must be made to determine the MAWP what can the inspector or the vessel engineer do to establish the MAWP ? a)

The lowest grade material and highest joint efficiency in the applicable code may be assumed for calculations.

b)

Assume MOC as SA 283 Gr.C and joint efficiency = 0.7.

c)

The vessel made of the unknown material must be removed from service and vessel of known material must be installed.

d)

The vessel of unknown material may be subjected to a hydrostatic tests while having strain gages on it to determine its yield strength and thus allowable stress.

8) An authorised API-510 vessel inspector shall have the following qualifications. Pick the one that does not belong in this list :-

9)

a)

Four years of experience inspecting in-service vessel systems

b)

High school education plus 3 years of experience in the design, construction, repair, operation, or inspection of pr. vessels, out of which 1 year shall be in performing/supervising the inspection on vessels

c)

Two year certificate in engineering or technology plus 2 years of experience in the design, construction, repair, operation, or inspection of pr. Vessels, out of which 1 year shall be in performing/supervising the inspection on vessels

d)

Degree in engineering plus 1 year experience in performing/supervising the inspection on vessels

Risk based inspections include which of the following :a)

Likelihood of failure assessment

b)

Consequence analysis

c)

Evaluation of inspection frequencies based on RBI

d)

All of the above

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IET/CH/TP/002-R2, Sept. 11

10)

11)

12)

13)

14)

An RBI assessment can be used to alter the inspection strategy provided :a)

The degradation methods are identified and evaluated

b)

The RBI is fully documented.

c)

A third party conducts the RBI

d)

Both A and B above

What climatic area may require a very active program for corrosion under insulation ? a)

Cooler dry locations.

b)

Very cold locations with year round temp ,less than 25 deg.F.

c)

Warmer, wet locations

d)

Warmer dry locations

Following vessels are exposed to mist over-spray and ambient temp 80 deg.F . Which of the items listed is not susceptible to CUI ? a)

Vessels operating at 200 Deg.F.

b)

Carbon steel vessels that normally operate in-service above 250 degrees F but are in intermittent service.

c)

Carbon steel vessels that normally operate in-service below 25 degrees F but are in intermittent service Attachments that protrude from insulated vessels and operate at temperature 120 to 200 deg.F.

d)

Carbon steel vessel systems, operating between 350 degrees F and 600 degrees F.

Soil-to-air (S/A) interfaces for partially buried vessels are a location where localised corrosion may take place. If the buried part is excavated for inspection, how deep should the excavation be to determine if there is hidden damage ? a)

12 to 18 inches

b)

6 to 12 nches

c)

12 to 24 inches

d)

6 to 18 inches

Erosion can be defined as :a)

galvanic corrosion of a material where uniform losses occur

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15)

b)

removal of surface material by action of numerous impacts of solid or liquid particles

c)

gradual loss of material by a corrosive medium acting uniformly on the material surface

d)

pitting on the surface of a material to the extent that a rough uniform loss occurs

A combination of corrosion and erosion results in significantly greater metal loss that can be expected from corrosion or erosion alone. This type of loss occurs at

a) slurries

16)

17)

18)

Areas exposed to high-velocity and high-turbulence of corrosive

b)

areas where condensation or exposure to wet hydrogen sulphide or carbonates occur

c)

surface-to-air interfaces of buried vessels

d)

areas where gradual loss of material occurs because of a corrosive medium

Environmental cracking of austenite stainless steels is caused many times by a)

exposing areas to high-velocity and high-turbulence streams

b)

excessive cyclic stresses that are often very low

c)

exposure to chlorides from salt water, .

d)

creep of the material by long time exposure to high temperature and stress

If external or internal coatings or refractory liners on a vessel are in good condition, what should an inspector do? a)

The coating or lining need not be removed for inspection,

b)

There is no alternative and entire liner should be removed for inspection

c)

At least 50% area must be removed for inspection

d)

At least 25% area must be removed for inspection

Fatigue cracking of vessel may result from a)

embrittlement of the metal due to it operating below its transition temperature

b)

erosion or corrosion / erosion that thin the piping where it cracks

224

IET/CH/TP/002-R2, Sept. 11

19)

20)

21)

22)

23)

c)

excessive cyclic stresses that are often well below the yield strength of the material

d)

environmental cracking caused by stress corrosion due to the presence of caustic, amine, or other substance.

Where can fatigue cracking typically be first detected ? a)

At points of low-stress intensification such as reinforced nozzles

b)

At points of high-stress intensification such as branch connections

c)

At points where cyclic stresses are very low

d)

At points where there are only the primary stresses.

What are the preferred NDE methods for detecting fatigue cracking ? a)

Eddy current testing ultrasonic A-scan testing,

b)

Liquid penetrant testing, magnetic particle testing .

c)

Visual testing, Hammer testing and/ or possibly ultrasonic testing

d)

hydro-testing, and / or possibly ultrasonic testing.

Water and aqueous solutions in vessel systems may freeze and cause failure because of the a)

expansion of solutions;

b)

contraction of solutions

c)

expansion of vessel materials;

d)

None of these

Vessel fabricated of or having components of 300 series stainless steel should be tested with __________ a)

water with a pH of 4

b)

water with a pH of 6

c)

water with a chloride content of less than 50 ppm chlorides

d)

Sea water

When evaluating the pits on corroded surface, using pit gauge, a. Monitor the actual pit depth and subtract it from Nominal thickness to obtain available thickness. b. the un-corroded surface contour line shall be first determined and pit depth adjusted accordingly, prior to calculating available thickness. c. .a or b. above does not make difference. d. None of above 225

IET/CH/TP/002-R2, Sept. 11

24)

The term “ away from weld” for recalculating the required thickness ( Vessels with E<1), means area lying away from weld __________ on either side of the weld or __________ times the minimum measured thickness on either side of the weld, whichever is greater. a)

25.

26)

27)

1’, 4

b) 1", 2

c) 2", 2

d) 2” , 4

Who establishes inspection interval for thickness measurements, and external visual inspections . a)

Vessel engineer;

b)

Owner-user or the inspector

c)

Chemical Engineer

d)

NDE engineer

Thickness measurement inspection for vessels (with remaining life >4 years) should be scheduled based on the calculation of not more than a)

one half the remaining life determined from corrosion rates or the maximum interval of 5 years whichever is shorter.

b)

one half the remaining life determined from corrosion rates or 10 years, whichever is shorter

c)

one fourth the remaining life determined from corrosion rates or the maximum interval of 10 years whichever is shorter.

d)

one quarter the remaining life determined from corrosion rates or 5 years, whichever is shorter.

When making the on-stream welding repairs and alterations to vessel the principles of __________ shall be followed :a)

API 2201

b)

API 510

c)

API 572

d)

ASME B&PV code

28) Repair and alteration work must be done by a repair organisation as defined in API 510 and must be authorised by the __________ prior to its commencement a) jurisdiction b) 29)

inspector

c)

owner-user

d)examiner

An inspector finds a longitudinal crack in the parent metal of a vessel being inspected after a 5 year run. Before repairing, he should:-

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IET/CH/TP/002-R2, Sept. 11

30.

a)

Notify the jurisdiction prior to the start of any repairs

b)

Write a detailed procedure for the repair organisations to use in repairing the crack

c)

Consult with the vessel engineer to identify and correct the cause of the crack.

d)

Consult with a metallurgist prior to writing a procedure to repair the crack.

Which of the following are essential elements of a Quality control system of a repair organization? a) b)

Organizational authority and responsibility Statements about Working (Inspection/repair)Procedures and their documentation Statement of controls to ensure Quality conformance All of the above

c) d) 31)

32)

33..

A repair procedure involving welding requires that the root pass of the weld be inspected before continuing the weld. A "hold" on the repair is required at this point. Who designates this "hold?" a)

A metallurgist

b)

The owner-user

c)

An API 510 inspector

d)

The welder supervisor

What type of repairs and procedures may the inspector give prior general authorization to continue (provided the inspector is satisfied with the competency of the repair organization)? a) major repairs and minor procedures b)

limited or routine repairs.

c)

major alterations and re-ratings

d)

minor re-ratings and alterations

Temper embrittlement is: a. Brittleness due to low temperature operation b. Brittleness due to Hydrogen Sulphide attack at high temperatures ( exceeding 700 deg. F) c. Loss of ductllity in Cr –steels due to incorrect PWHT and High temperature service d. None of above.

34.

“In austenitic stainless steels, in presence of chlorides spontaneous failure may occur under combined action of corrosion and tensile stress” What type of phenomenon is described by this statement: a. b. c. d.

Sensitization of stainless steel Stress corrosion cracking Intergranular corrosion of stainless steels Chromium-decay of stainless steels. 227

IET/CH/TP/002-R2, Sept. 11

35.

Sour crude is more corrosive than sweet crude because a. Sour crude is heavier than is sweet crude b. Sweet crude has more waxing tendency (compared to sour crude) which forms protective layer on metallic surfaces hence sweet crudes are less corrosive. c. Sour crude contains high content H2S and sulpher compared to sweet crude which lead to several types of corrosion d. None of the above.

36.

Erosion would normally be exhibited at .. a. b. c. d.

37.

HCl is more corrosive in refining sour crudes because a. b. c. d.

38.

Hydrogen blistering near liquid level. Hydrogen blistering in vapor space Hydrogen blistering near the bottom of vessel below the liquid level None of above.

Shells of vessels adjacent to inlet impingement plates are susceptible to a. b. c. d.

40.

In presence of H2S, corrosion of iron by HCl becomes cyclic reaction regenerating HCl. HCl liberates chlorine in presence of sulpher which causes stress corrosion cracking HCl liberates Hydrogen in presence of sulpher causing Hydrogen embrittlement. None of the above

In planning for an internal inspection of a vessel that has acidic corrodents, what type of corrosion would you expect to find on the vessel shell from inside, a. b. c. d.

39.

Wear plates of the saddles Baffle plates in agitator vessels Shell plates of skirt support All of the above

Stress-corrosion cracking Erosion Hydrogen embrittlement Any of the above depending upon ambient conditions

H2S is in sour crude is more harmful in presence of: a. b. c. d.

Oxygen Water (i.e. Wet H2S) Sulphur a and c above

228

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41.

The leak tightness of the relief valves is tested on the test block at a pressure equal to: a. b. c. d.

42.

Same as set pressure 90% of the set pressure Same as reseat pressure None of the above

What can be done to extend the life of a 2” thk. vessel with a corroded area in the shell plate 6 inches from the weld, a joint efficiency of less than 1, and a corrosion thickness currently near the minimum required thickness? a. b. c. d.

Recalculate t minimum for current operating conditions using E < 1. Recalculate t minimum for current operating conditions using E = 1. Recalculate t minimum for design conditions using E = 1. Monitor the thickness during the run.

43. Re-rating may be done after which of the following requirements are met? a) b)

c) d)

Calculations from either the manufacturer or an owner-use pressure vessel engineer experienced in pressure vessel design, fabrication or inspection shall justify the re-rating. The re-rating is in accordance with the construction code to which the pressure vessel was originally built or by computations that are determined using the appropriate formulae in the latest edition of the ASME Code Current inspection records verify that the pressure vessel is satisfactory for the proposed service conditions and that the corrosion allowance provided is adequate. All of the above

44. In planning for an internal inspection of a vessel that has acidic corrodents, what type of corrosion would you expect to find on the vessel shell from inside, a) b) c) d) 45.

Hydrogen blistering in the base metal Uniform corrosion of vessel wall Erosoin of vessel walls. None of above.

The principal reason for inspecting a pressure relief device is to determine: a. b. c. d.

46.

Condition of pressure relief device and if it is functioning properly The remaining life of pressure relief device. The spring coil diameter. The body thickness.

Where (typically) are balanced safety relief valves used in refineries? a. For pressure control and bypass . b. On steam boiler drums and super heaters. 229

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c. When the discharge from the valves must be piped to remote points d. All of the above 47.

Which of the following are possible reasons for improper performance of valves? a. b. c. d.

48.

Which of the following tests must be conducted on a valve as soon as it has been removed out of a system a. b. c. d.

49..

Corrosion Damaged seating surfaces Failed springs All of the above

Visual Inspection Hydrotesting of valve body Radiographic testing Check set-pressure .

Which of the following is / are to be undertaken in case the ownership and location of vessel are changed a. The vessel shall be hydro tested only b. The vessel shall be internally and externally inspected before it is re-used c The allowable conditions of service shall be established and the next period of inspection shall be established for the new service. d. Only “b” and “c”

50..

For repairs on vessels which have been subject to PWHT as a Service requirement and made of P1 or P3 Steels, which of the following options may be adopted to avoid PWHT after repair a. Conduct RT after 48 hours of completion of all hot work b. Pre- heat to al least 300 deg F for a distance 4’’ or 4 times repair depth.r c. Use SMAW/GMAW/GTAW process and conrol interpass temp not to exceed 600 deg.F d. Both b and c.

51.

Which of the following could cause chatter in valves? a. b. c. d.

52.

Improper material of construction Overpressure Erosion Large length piping to the valve inlet from the vessel

API 576 does not address T. a. Valve testing on test benches in shop b. Application of rupture discs 230

IET/CH/TP/002-R2, Sept. 11

c. Training requirements for mechanics involved in inspection and repair of pressure relieving devices d. All of the above 53.

For vessels which are supported on concrete saddles and working in an area where the humidity is high which areas on them are typically susceptible to external corrosion? a. b. c. d.

54.

H2S is in sour crude is more harmful in presence of: a. Oxygen

55.

56.

At the anchor bolts in the foundation At the Points of contact of the metal surface with the concrete All of the above None of the above

b .Water (i.e. Wet H2S)

c. Sulpher

d. ‘a’ and ‘c’ above

The leak tightness of the relief valves is tested on the test block at a pressure equal to: a) Same as set pressure b) 90% of the set pressure c) Same as reseat pressure d) None of the above Inspection records contain the following information for a particular thickness measurement location (TML) on a dished head.(Thk. in inches) Thickness

Year

0.500

0

0.425

5

0.400

10

On the basis of the information above, the long-term corrosion rate for the location is: a . 1 ½ mils per year. b. 5 mils per year. c. 10 mils per year. d. 100 mils per year. 57.

A certain C.S .vessel which required impact testing was required to have PWHT initially according to code requirement. After 10 years when repaired by welding PWHT is to be carried out. performing PWHT is found to be impracticable. Which of the following is relevant (according to API-510) a. b. c. d.

PWHT may be exempted, if proper NDE is carried out Carry out Temper-bead welding as on alternative PWHT. Carry out both Hydro-testing and Pneumatic Testing in lieu of the PWHT Carry out preheating to min. 200 deg. F

231

IET/CH/TP/002-R2, Sept. 11

58

A cylindrical shell with thickness=4.0”, ID=96”, S=17100 and E=0.85 showed metal loss of 1/8” in areas between 4” and 8” on either side of the longitudinal welds. You analysis of situation is. a. b. c. d.

59.

Crown can be taken as spherical portion of radius K1 x D K1 depends on D/2h ratio Crown lies within concentric circle of 80% shell diameter All of above

For non-continuous corrosive service with remaining life 25 years, external inspection shall be performed not later than : a. b. c. d.

63.

API 620 API Recommended practice 576 IRE Chap-II. ASME Sec. VIII

According to API 510 for ellipsoidal head, for crown portion thickness recalculation: a. b. c. d.

62.

They shall meet the requirements stipulated in NACE std. The carbon content shall not be over 0.35% Welding repair shall be done by using only the GTAW process All of the above

Which of the following documents gives typical corrosion phenomenon encountered in in Refineries? a. b. c. d.

61.

b and c above

Materials used for making repair by welding in carbon steel vessels shall have the following limitations? a. b. c. d.

60..

Recalculate shell thickness ‘t’minimum considering E=1.0 The thinned area is on or within weld area hence (a) above can not be adopted Prepare repair procedure and restore the metal loss as per Api -510

10 years 12.5 years 5 years None of above

An ellipsoidal head has an internal diameter of 76 inches and depth of 21 inches (including a straight face dimension of 2 inches). What should its spherical ( crown) radius be? a. b. c. d.

76.9 inches 15.6 inches 68.4 inches All of the above 232

IET/CH/TP/002-R2, Sept. 11

64. After Hydro testing of the vessel is completed what shall be the next step? a. b. c. d.

Open drain valve to remove the water Open the vent valve before opening the drain valve Remove the pressure gauge before draining the valve Vessel shall not be drained at least for 15 minutes after the pressure test is completed.

65. For carrying out temper – bead welding technique in lieu of PWHT, apart from other requirements, which of the following is acceptable? a. b.

c. d. 66.

The root and final pass of weld shall be radiographed. Weld metal shall be deposited for second pass while the first pass below the second pass is still not cooled down and its cooling rate is retarded due to the heat of second pass After depositing each layers of the weld, The weld shall be DP checked Both b and c.

In post weld heat treatment inspection what important things you will verify a. b. c. d.

Loading temperature and heating rate Holding temperature and holding time Cooling rate All of the above are important things to be verified

67. Calculate the remaining life and external insp. interval of a vessel given the following data: Actual thickness = 0.955 inch Minimum thickness required = 0.755 inch Thickness at pervious inspection 5 years prior to present inspection = 1.025 inch a. b. c. d.

20 years, 10 years 14 years, 5years 28 years, 10 years None of the above

68. The period between External inspections for vessels (remaining life > 4 years) shall not exceed which of following a. b. c. d.

Smaller of: One half of the remaining life of the vessel and 10 years 5 years The lesser of “a” and “b” The higher of a. and b.

233

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69. ..A good commercial penetrant should have a:

70

a. low flash point b. high flash point c. high viscocity d a and c Vessel containing lethal substance having thickness of shell 20mm requires a. b. c. d.

71

Which of the following are commonly used techniques of surface preparation for inspection a. b. c. d.

72.

10 mpy

b. 12 mpy

c. 14 mpy

d. none of above

If the vessel in above question has minimum permissible thickness = 0.618” for the present design conditions. What will be estimated remaining life of the vessel if corrosion rate remains same? a. b. c. d.

75.

Same as parent material Higher than parent material Lower than parent material All of the above

A Vessel which was inspected six years ago and had shell thickness = 0.870”. As on today the thichness as reported by filed inspection is 0.786. What was the corrosion rate over last six years: a.

74.

Wire brushing Sand – blasting High pressure water blasting All of the above

According to API-510, restoration by welding of parent metal loss may be made by using by electrodes having tensiles strength: a. b. c. d.

73.

Spot radiography Full length radiography No radiography Penetrant is sufficient if radiography testing is not available

10 years 12 years 14 years none of above

For a vessel in Q..73 inspection a. b.

and 74 find

interval for next

thickness

10 years 6 years 234

IET/CH/TP/002-R2, Sept. 11

c. d.

8 years 5 years

76. For a vessel, remaining life is estimated as 22 years from now, next planned external inspection shall not be later than: a. b. c. d.

11 Years 10 Years 5 Years None of the above

77. .Which of the following may be classified as “internals” of vessels? a) Catalyst bed b) Nozzles which are extended inwards c) Demister pads d) “a” and “c”

78. Two plate tensile test specimens have been tested and found to be acceptable.The characteristics of each specimen are as follows : Specimen 1: Width of 0.752”; thickness of 0.875”; ultimate tensile value of 78.524 psi Specimen 2: Width of 0.702”; thickness of 0.852”; ultimate tensile value of 77,654 psi What is the ultimate load for each specimen that was reported on the laboratory report? a) b) c) d)

51,668 & 46,445 67,453 & 56,443 78,524 & 77,654 None of the above

79. What is the maximum defect permitted on the convex surface of a welder qualification bend test after bending except for corner cracks and corrosion resistant weld overlay? a) b) c) d)

¼ inch 1/8 inch 1/16 inch 3/16 inch

235

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80.. The test that determines the ultimate strength of groove-weld joints is a: a) b) c) d)

Notch Toughness Test Tension Test Fillet Weld Test Guided-Bend Test

81. Welders carrying out repair/alteration according to API 510 shall be qualified according to a. b. c. d.

API 1104 welding qualification code ASME Sec. IX code Any one of a or b above None of a or b above

82. For corrosion area of considerable size; thickness averaging along most critical element shall not exceed following length for 60” ID vessel and 72” ID vessel. a. b. c. d.

20” and 40” respectively 16” and 24” respectively 20” and 24” respectively none of the above

83..Certification of contaminants shall be obtained for all PT materials used on : a. b. c. d.

Carbon steels Ferritic stainless steels Austenitic stainless steels None of the above

84 The scope of the ASME Boiler and Pressure Vessel, Code, Section V includes: a) b) c) d)

NDE acceptance crtieria How to perform NDE to achieve a desired result Where to do NDE ( i.e. what welds to examine ) All of above.

85 For Ammeter calibration for Magnetising equipment , The allowable tolarence is: a.

+ 5%

b. + 10 %

c. + 15 %

d.

+ 20 %

236

IET/CH/TP/002-R2, Sept. 11

86. For a project involving Vessel welds at site procedure and 4 new welders were to be qualified. In this case, identify correct statement from the following: a. Welder qualification must be performed before procedure qualification b. Welder qualification must be performed after procedure qualification c. Out of Welder qualification and procedure qualification, anything can be performed before d. Welder qualification must be performed simultaneously, with procedure qualification without waiting for the test results for PQRr. 87 .Which of the following are commonly preferred to know the process side degradation of Pressure vessels a) b) c) d)

On –stream inspection. Internal inspection External inspection as alternative to internal inspection Any of above is OK

88. According to ASME sec. IX , A welder for SMAW can be qualified by following minimum tests a. b. c. d.

1 tensile and 2 bend tests 2 bend tests only 2 tensile tests and 1 bend tests 1 tensile and 1 radiography

89. Use of Radiography is made for: a. b. c. d. 90.

When dial-type indicating and recording pressure gauges are used to monitor leak testing, the maximum gauge range shall not exceed which multiple of the expected test pressure? a. b. c. d.

91..

Performance qualification only Procedure qualification only Both a. and b. Use of Radiography is not permitted by ASME Sec. IX.

1½times 2½times 3times 4 times

Authorization for which of the following, the approval from vessel engineer is not mandatory 237

IET/CH/TP/002-R2, Sept. 11

a. b c. d. 92.

Changing the damaged flange to a new flange of same rating. Changing a nozzle size from one not requiring reinforcement pad to the one requiring reinforcement pad for both a and b For none of the above

In a certain arc welding process, coalescence of metals is produced by an arc between a consumable bare electrode and the work, and shielding is obtained from a gas or gas mixture. This process is called: a. GMAW d.SMAW

93.

b .GTAW

c. SAW

For calculating MAWP for vessel which is put in service the wall thickness used in computations is: a. Actual thickness as determined by inspection. b. Actual thickness minus the estimated corrosion loss before the date of next inspection c. Actual thickness minus twice the estimated corrosion loss before the date of next inspection d. None of the above

94TFor MT examination by Prod technique the magnetising current required depends on a. ..Prod Spacing b. Thickness of item under Inspection c. .a & b. above d. None of above 95.. A welder has made 25 SMAW groove welds, but the guided bend test for the welder's qualification was never performed. In order to avoid cutting out all of the production welds made by this welder, which of the following minimum steps would be taken to validate the qualification? a. Radiograph the welder's first production weld and accept the qualification based on acceptable weld quality by radiography. b. There is no alternative to qualifying a welder by the guided bend test. c. Have the welder prepare a test coupon and have the bend test done on that. d. Reject the welder and the welds. Do not use them in actual job. 238

IET/CH/TP/002-R2, Sept. 11

96. Which of the following represent grouping of base-metals in ASME IX ? a.

P – Nos

b. B – Nos

c. S – Nos

d. both

a and c. 97. While deciding the governing thickness for crown portion for corroded 2:1 ellipsoidal head, API 510 stipulates that & crown thickness shall be calculated a. According to relevant ellipsoidal dished head formula b. According to code formula for spherical heads with head radius equal to 0.9 D, where D is shell dia meter. c. Thickness of crown shall be same as knuckle thickness d. None of the above. 98.. Calculate the remaining life of a vessel given the following data: Actual thickness = 0.955 inch Minimum thickness required = 0.755 inch Thickness at pervious inspection 5 years prior to present inspection = 1.025 inch a) b) c) d)

20 years 14 years 28 years None of the above

99. .For a vertical with column int. dia. = 48'' and height (T-T) =80ft, The vessel MAWP is 60 psi. The vessel part MAWP for bottom dished head (2: 1 Ellip type) will be a) b) c) d)

94.6 psi 82.8 psi 95.5 psi None of above

100 ..How is hammer testing utilized? a) As a preliminery survey for thinned areas. b) As a independent test method for which ASNT Certification in NDT is available c) As a very important tool in the hands of the Authorized inspection only d) To carry out Carpy impact test .

.

239

IET/CH/TP/002-R2, Sept. 11

API 510 Preparatory Review Exam 2 –Closed Book ANSWER SHEET

Sr. # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

A
O O
O O O
O O O O O O
O
O O O
O O O O O
O O O O O O O O O

O O

B O

O O O
O O O O O

O O O O

O O



0
O O O
O
O
O O



C O O O 0

O O O O
O O O O
O
O O O
O O O O O 0
O
O
O
O O O O O

D O O O O O O O O

O
O O O O O O O O O O O O O O O O O
O O O O O O O O O O

Sr. # 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80

A O O O

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O
O O

B
O O O O O O O O O O O


O
O
O O O O

O
O

O O O

O O O



C O
O O O
O O O O O
O O O
O O O
O

O O O O
O O O O
O O
O O O O

D O O
O O O




O O O O O O
0 O
O O O O
0 O O O

O O O O
O O O

Sr. # 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120

A O O O O O O O O
O

O O
O O O O
O O O O O O O O O O O O O O O O O O O O

B
O O




O O O O O
O O

O O O O O O O O O O O O O O O O O O O O O O

C O

O O O O O O O O O
O O O O O
O O O O O O O O O O O O O O O O O O O O O

D O O O O O O O O O
O O O O O
O O O O O O O O O O O O O O O O O O O O O O O O

240

IET/CH/TP/002-R2, Sept. 11

API 510 Preparatory Review Exam 3 –Open Book 1.

What are the A number and F number for the electrode E 7018? 1. 2. 3. 4.

2.

1 and 4 4 and 1 1 and 5 6 and 1

What is the geometric unsharpness allowed as per code for a thickness of 2.0” (50.8 mm) as per code? 1. 2. 3. 4.

3.

0.020” ( 0.508mm) 0.030” (.00.762mm) 0.010 (0.254mm) None of the above

A figure is given for the pits and you have to answer about the acceptability of the pits Given- thickness = 1 ½”, CA = ¼”, ID = 70” 1 2”

Sr. No.

Size

Depth

1

1 ½”

¼”

2

½”

¾”

3

1 ¼”

½”

4

2 ¾”

5/8”

1 ½” 2 3 ½” 3

1. 2. 3. 4. 4. a

3”

4

1, 3 & 4 are rejected 1 & 4 are rejected 3 & 4 are rejected All are rejected

TML locations are given on the shell. b

c

d

e

241

IET/CH/TP/002-R2, Sept. 11

1.3”

1.25”

1.4”

1.38”

1.28”

1

1.32”

1.52”

1.48”

2

5”

1.28”

1.23”

Longitudinal axis of shell

1.33”

1.35”

1.31”

1.47”

1.45”

1.29”

1.36”

1.49”

1.40”

1.42”

3

4

5 1.49”

1.39”

1.42”

1.36”

1.23”

Given: shell dia. = 50”. The pitch for the above reading is 4” X 4”. The required thickness of the shell is 2” (circumferential stress governed). What is the minimum thickness to be considered after averaging for calculation of MAWP? 1. 1.322” 2. 1.392” 3. 1.316” 4. 1.426” 5.

The material identification for the following items must be done with the heat mark on the item and the correlating test certificate 1. 2. 3. 4.

6.

A105 forged flange A193 fittings A516 Gr. 70 plate None of the above

A vessel with P-3 base metal was repaired with SS overlay. The base metal in the are of repair shall be examined with: 1. 2. 3. 4.

RT PT UT MT

242

IET/CH/TP/002-R2, Sept. 11

7.

SA516 Grade 70 – 316L cladded material with pitting corrosion was repaired by SS Overlay after cooling to ambient temperature the repair shall be inspected by: 1. 2. 3. 4.

8.

A 1” thickness plate was joined with 1 ½” plate with a groove weld to make a torisphrical dish to shell joint. The allowable reinforcement for the joint shall be: 1. 2. 3. 4.

9.

RT PT UT MT

¼” 3/16” 5/16” 1/8”

For all other things being constant what type of head will require maximum thickness? 1. 2. 3. 4.

Hemispherical dish end Torispherical dish end Ellipsoidal dish end Flat head

10. The P numbers are assigned on the basis of 1. 2. 3. 4.

Hardness Composition weldability & mechanical properties Ductility only None of the above

11. Loads above the elastic limit will cause permanent deformation, which is called as: 1. 2. 3. 4.

Elastic flow Modulus of elasticity Plastic flow None of the above

12. The description, minimum design criteria and general information regarding air cooled heat exchangers is available in: 1. 2. 3. 4.

API 661 API 653 API 510 API 576 243

IET/CH/TP/002-R2, Sept. 11

13. The radiographic review form shall include all but: 1. 2. 3. 4.

Radiograph location Evaluation & disposition Geometric unsharpness Date

14. The radiographic films shall be retained upto the time: 1. 2. 3. 4.

Service inspection is carried out The vessel is in existence Manufacturer’s report has been signed by the inspector Customer inspection is complete

15. A 2” SA 516 Grade 60 material can be used for pressure vessel without impact testing up to a temperature of degrees F. 1. 2. 3. 4.

26 degrees F. 63 degrees F. 99 degrees F. – 4 degrees F.

16. The length of Charpy Impact Sample shall be: 1. 2. 3. 4.

4” (101.6 mm.) 2” (50.8 mm.) 2.165” (55 mm.) None of the above

17. The impact testing was carried out for a 1 ½” thickness weld with minimum specified yield strength of 45 ksi. The values were observed as 20 ft.lb, 15 ft.lb and 10 ft.lb. The results are 1. 2. 3. 4.

Acceptable Retest required Not acceptable Data insufficient

18. The welder’s qualification by radiographic testing is possible for all the processes except: 1. 2. 3. 4.

SMAW with low hydrogen electrodes GTAW without filler wire GMAW short circuiting mode SAW with granular flux 244

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19. A groove weld was made with 1 ¼” thickness plate with SMAW process for PQR Qualification and the test were found acceptable. This PQR can be used up to a maximum weld thickness of: 1. 2. 3. 4.

1 ¼” 2.5” 8” None of the above

20. A pressure vessel was manufactured and ready for hydro test. The operating pressure is 90 psi. The MAWP is 100 psi. The hydro test pressure for this vessel shall be: 1. 2. 3. 4.

130 psi 117 psi 150 psi 135 psi

21. Elliptical head to shell with backing strip what is category (ans: B) 1. 2. 3. 4.

A B C D

22. A pressure vessel was constructed with 3”thickness hemispherical head and 4 ½” thickness shell. The material of construction is SA 516 Grade 70. The permissible misalignment for the circumferential seam between head and shell is 1. 3/16” 2. 3/8” 3. 5/16” 4. 1/8” 23. A pressure vessel long seam ( E =1) was tested for radiography with a thickness of plate 1 ¼ inch and the joint flush ground. The maximum slag length acceptable for this weld will be 1. 2. 3. 4.

0.417 in 0.833 in ¼ in Slag cannot be accepted in this joint, as the E value assumed is 1

24. The pressure vessel cir seam was to be taken spot radiography and the thickness was ½ in. The maximum acceptable slag length for this joint will be 1.

8.47 mm 245

IET/CH/TP/002-R2, Sept. 11

2. 3. 4.

4.23 mm 6.35 mm 12.7 mm

25. SA516 Gr. 70 pressure vessel was manufactured with 2” thickness shell. The PWHT requirement for this vessel will be: 1. 2. 3. 4.

required with 1100 degrees F. minimum holding temperature and 2 hours soaking time not required required with 1100 degrees F. minimum holding temperature and 1 hour 15 min. holding time none of the above

26. In addition to the Authorized ASME Certificate holder, owner user, a contractor with acceptable qualifications, a repair organization can be: 1. 2. 3. 4.

Good fabricator Insurance organization An organization that is authorized by the legal jurisdiction None of the above

27. The vessel is inspected after 10 years of service. For the acceptance of the vessel which will be the governing document? 1. 2. 3. 4.

ASME Sec. VIII Div. 1 API 510 AWS D1.1 API 572

28. In addition to the likelihood of failure the RBI assessment (API RP 580) must include: 1. 2. 3. 4.

The associated consequence of failure Remaining life Minimum thickness Maximum period for replacement

29. A vessel was having 90” diameter and 2” thickness. There were some corrosion patches observed. The circumferential stress governed. The thickness averaging shall be done over a length of not exceeding: 1. 2. 3. 4.

30” 20” 40” None of the above

246

IET/CH/TP/002-R2, Sept. 11

30. A 2” thickness vessel was having a joint efficiency of 0.85 a corrosion patch was observed at 6” from the weld. The joint efficiency to be considered for deciding the minimum thickness for this patch shall be: 1. 2. 3. 4.

0.85 1.00 0.70 0.90

31. The ‘t actual’ is defined in API 510 as: 1. 2. 3. 4.

The actual thickness at the time of fabrication The minimum thickness at the time of dish manufacturing The actual thickness, in inches at the time of last inspection The actual thickness, in inches, at the time of inspection for a given location or component

32. In addition to the construction and design information, operating & information history, repair alteration and rerating information the pressure vessel record shall contain also. 1. 2. 3. 4.

Fitness for service assessment document Repair personnel training qualification Pressure test reports Service reports

33. The pressure vessel was inspected & a crack was found at the junction of the nozzle to shell weld, which needs repair. This repair 1. 2. 3. 4.

Should be attempted with consultation of authorized pressure vessel inspector Should be attempted with prior consultation with a pressure vessel engineer Should be attempted with the AI’ (ASME) approval Should be attempted with the repair organization’s QC manager

34. The general corrosion rate of a vessel is known to be less than 0.005”(0.125 mm.) per year and the estimated remaining life is greater than 10 years. In this situation n order to substitute on-stream inspection for internal inspection the following conditions are met: a) No questionable condition in external inspection b) Temperature not exceeding creep rupture range lower limit c) No environmental cracking d) Not bonded What is the remaining condition to be fulfilled? 1. External inspection must be done by API Certified Inspector 2. Internal inspection is done with boroscope 3. Pressure vessel engineer is available at the time of inspection 247

IET/CH/TP/002-R2, Sept. 11

4. The corrosive character of contents, including the effect of trace components, has been established by at least 5 years of same or comparable service experience with the type of contents being handled 35. If a filler metal is used that has a minimum specified tensile strength lower than the minimum specified tensile strength of the base metal, the compatibility of the filler metal chemistry with the base metal chemistry shall be considered along with the following:     

The repair thickness shall not be more than 50 % of the required base material thickness, excluding corrosion allowance. The thickness of the repair weld shall be increased by a ratio of minimum specified tensile strength of the base metal and minimum specified tensile Strength of the filler metal used for the repair. The increased thickness of the repair shall have rounded corners and shall be blended into the base metal using a 3-to-1 taper.

What else to be concerned along with this? 1. 2 3. 4.

The post weld heat treatment is to be done The pre-heat is required to be done The repair shall be made with a minimum of two passes The welding technique shall be a controlled deposition, temper-bead or half- bead technique.

248

IET/CH/TP/002-R2, Sept. 11

API 510 Preparatory Review Exam 3 –Open Book ANSWER KEYS 1

1(QW422/432)

11

3(Gen)

21

2

31

4(6.4)

2

2(T285)

12

1(572chap3,ref.)

22

1(UW33)

32

1 (6.7)

3

4(5.7)

13

3(T290)

23

1(UW51)

33

2(7.1.3)

4

3(5.7)

14

3(UW51)

24

3(UW52)

34

4(6.4)

5

3(UG 93 a-1)

15

1(UCS 66)

25

UCS-57

35

3

6

3(7.26)

16

3(UG84)

26

3. Def. 510

7

2(7.26)

17

1(UG84)

2

2

8

2(UW 35 table)

18

3(QW304)

28

1(6.2)

9

4(UG 32)

19

2(QW51)

29

1(5.7)

10

2 (QW 420.1)

20

1(UG99)

30

2(5.7)

Legend: Section VIII Div. 1…… U Section V……………………… T Section IX…………………….QW API 510………………………. API 572……………………….572 API 576……………………….576 IRE Chapter II…………………IRE Gen…………………………….General

249

IET/CH/TP/002-R2, Sept. 11

API 510- INSERVICE PRESSURE VESSEL INSPECTOR PREPARATORY COURSE

PART IX

QUESTION BANK QUESTIONS ON ASME CODES

250

IET/CH/TP/002-R2, Sept. 11

API 510 CERTIFICATION PREPARATORY COURSE Practice Questions. ( Closed Book )

ASME Sec. VIII Div.1

1. A vessel containing lethal substance having thickness of shell 0.75 inch requires e.

Spot radiography

f.

Full radiography

g.

UT Examination of all longitudinal welds sufficient if radiography testing is not available

h.

Penetrant Examination of all welds is sufficient if radiography testing is not available

Ans :

b.

Ref. ASME Sec.VIII –1, UW-11a

2. You are calculating the required thickness of a cylindrical shell under internal pressure. The inside radius including corrosion allowance is 24 in. The corrosion allowance is 0.125 in. What inside radius would you use?

A. B

24 in. 24.125 in.

C.

48.50 in.

D.

26 in.

Ans :

b.

Ref. ASME Sec.VIII –1, UG-16e

3. A small liquid relief valve installed on the vessel set to what multiple of the hydrostatic test pressure is a recommended to prevent overpressure and damage

251

IET/CH/TP/002-R2, Sept. 11

A.

1.1

B.

1-1/4

C.

1-1/2

D.

1-1/3

Ans :

D.

Ref. ASME Sec.VIII –1, UG-99

4. Postweld heat treatment when required shall be done _____ A.

Either before or after the hydrostatic test

B.

Prior to minor repairs

C.

Before hydrostatic test

D.

After hydrostatic test

Ans :

C.

Ref. ASME Sec.VIII –1, UG-99

5. Of the types of stresses placed on a thin walled cylinder the most severe is; 1.

Circumferential

2.

Longitudinal

3.

Compressive

4.

Radial

Ans :

1.

Ref. Pressure vessel Fundamentals

6. The rules for impact testing of carbon steel in Section VIII vessel materials require what kind(s) of impact test.

1. Brinell & Rockwell 2. Izod & Charpy V-notch 3. Charpy V-notch only is acceptable. 4. Brinell only is acceptable Ans :

3.

Ref. ASME Sec.VIII –1, UG-84 252

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7. When dial-type indicating and recording pressure gauges are used to monitor leak testing, the maximum gauge range shall not exceed which multiple of the expected test pressure? e. 1½times f.

2½times

g. 3times h. 4 times Ans :

D.

Ref. ASME Sec.VIII –1, UG-102

8. After receipt of 3 plates , 20m ordered Thickness, actual thicknesses were observed as 19.5mm, 20.1mm 19.8mm.after inspection. How many plates will you accept? a. 1 . b. 2. c. none . d.

Ans :

b.

all.

Ref. ASME Sec.VIII –1, Ug-16c

9. In PWHT of pressure vessels that are built in carbon steels : a)

Minimum PWHT temperature increases with increase of vessel thickness

b)

PWHT time increases with increasing vessel thickness

c)

Thickness has no effect on stipulated minimum PWHT temperature and time

d)

Only (a) and (b) above Ans :

b.

Ref. ASME Sec.VIII –1, Table UCS-56

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10. For external pressure calculations, the value of E to be used in the ASME code formula , is based on

e)

E = 1 for full radiography

f)

E = 0.85 for spot radiography

g)

E = 0.7 for no radiography

h)

E used in formula is actually modulus of elasticity it does not depend on radiography Ans :

d.

Ref. ASME Sec.VIII –1, UG-28

11. A vessel is to undergo a hydrostatic test after fabrication the test pressure will be 500 psi. Using commercially available gauges what is the minimum and maximum gage pressure range acceptable ? 1. min.0-750 , max.0-2000 psi 2. min.0-1000 , max.0-3000 psi 3. min.0-600 , max.0-2000 psi 4. min.0-1000 , max.0-3000 psi

Ans :

1.

Ref. ASME Sec.VIII –1, UG-102

12. You are fabricating a vessel to ASME section VIII div. 1. The dish ends are fabricated by your subcontractor (other company). For the dish end blank fabrication (joining 2 plates)

a.

Subcontractor has to write a WPS and get the PQR qualified to support the WPS

b.

Subcontractor can use your procedure qualification record as it is your job only

c.

Will be decided on the basis of time availability 254

IET/CH/TP/002-R2, Sept. 11

d.

All of the above are correct answers. Ans :

a.

Ref. ASME Sec.VIII –1, UW-28

13. You are checking a plate received for the pressure vessel fabrication. What will be your action plan? a.

Corelate test certificate with applicable specification

b.

Corelate heat marks and identification with the test certificate.

c.

thickness check

d.

All of the above are necessary action before accepting the plate.

Ans :

d.

Ref. ASME Sec.VIII –1, UG-16c and UG-93a

14. What will be the minimum inspection pressure if Pneumatic testing was carried out at 275 psig. as per code a)

275 psi

b)

250 psi

c)

200 psi

d)

260 psi

Ans :

b.

Ref. ASME Sec.VIII –1, UG-100

15. The hydrostatic pressure caused by 100 ft of liquid column (sp. gr. = 1) will be: a)

10 psi

b)

43.3 psi

c)

4.33 psi

d)

None of the above Ans :

b.

Ref. Body of Knowledge API 510

16. All the welds joining nozzle to the shell can be described as 255

IET/CH/TP/002-R2, Sept. 11

a)

Type A welds

b)

Category C welds

c)

Type B welds

i)

Category 1 welds

Ans :

b.

Ref. ASME Sec.VIII –1, UW-3.

17. Any offset while welding plates of different thicknesses shall be provided a taper transition of ______

a.

3 to 1 min.

b.

4 to 1 min.

c.

3 to 2 min.

d.

1 to 2

Ans :

a.

Ref. ASME Sec.VIII –1, UW-9.

18. The welds joining Hemispherical head to shell are described as

a)

Type and category both are A.

b) Category C weld c) Category B weld d) Category A weld Ans :

d.

Ref. ASME Sec.VIII –1, UW-3.

19. Of the following heads; which is normally required to be the thickest all things being equal?

1. Hemispherical 2. Flanged and dished 3. 2 to 1 elliptical 4. All have equal thickness

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Ans :

4.

Ref. ASME Sec.VIII –1, UG-32

20. After Hydro testing of the vessel is completed what shall be the next step?

e.

Open drain valve to remove the water

f.

Open the vent valve before openings the drain valve

g.

Remove the pressure gauge before draining the valve

h.

Vessel shall not be drained at least for 15 minutes after the pressure test is completed.

Ans :

b.

Ref. General Knowledge

21. In magnetic particle testing the linear indication is an indication of 2mm width and 5 mm length was found. Identify this indication as linear or rounded. a.

linear indication

b.

rounded indication

c.

both (a) and (b) are correct

d.

both (a) and (b) are wrong.

Ans :

b.

Ref. ASME Sec.VIII –1, App.4

22. ASME Sec. VIII Div. 1, defines “Weld joint category” as: a.

Type of weld, i.e., Single V type, Double V type, U type etc.

b.

Welds made by same WPS belong to same category.

c.

Location of weld, i.e., longitudinal, circumferential, nozzle attachment weld etc.

d. Ans :

Type of weld joint, i.e., Butt-weld joint, fillet weld joint, lap joint, etc. c.

Ref. ASME Sec.VIII –1, UW-3.

23. The leg of a properly deposited equal fillet weld is 1 inch. The throat dimension for this weld will be approximately: a.

1.09 inch

b.

0.808 inch

c.

0.707 inch 257

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d. Ans :

c.

0.965 inch

Ref. Body of Knowledge API 510.

24. If a vessel has both longitudinal and circumferential welds are type 1 and spot radiographed only, then stamping on name plate will be: a.

RT1

b.

RT2

c.

RT3

d.

RT4

Ans :

c.

Ref. ASME Sec.VIII –1, UG-116e.

25. A vessel is to be pneumatically pressure tested to 250 psi. This test pressure will be reached in how many stages of pressurization? a.

5 stages

b.

2 stages

c.

6 stages

d.

7 stages

Ans :

c.

Ref. ASME Sec.VIII –1, UG-100.

26. Prior to witnessing a pneumatic test of a pressure vessel, the inspector should: a.

Ensure that welds around nozzles were inspected by PT or MT prior to commencement of test.

b.

Ensure that test pressure is maintained throughout the leak testing inspection.

c.

Ensure that all butt welds were UT checked prior to commencement of test.

d. Ans :

a.

Both a and b Ref. ASME Sec.VIII –1, UW-50. 258

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27. A vessel has a torispherical head at top and 2:1 ellipsoidal head at bottom both are welded to the shell with double welded joints. The circumferential welds joining these heads to the shell can be described as:

a)

Type A, Category 1

b)

Type B, Category 2

c)

Type B, Category 1

d)

None of the above

Ans :

c.

Ref. ASME Sec.VIII –1, UW-3.

28. All the welds joining nozzle to the shell can be described as

Ans :

a)

Type C welds

b)

Category C welds

c)

Type D welds

d)

Category D welds

c.

Ref. ASME Sec.VIII –1, UW-3.

29. The radiographic films shall be retained upto the time: a. Service inspection is carried out b. The vessel is in existence c. Manufacturer’s report has been signed by the inspector d. Customer inspection is complete Ans :

c.

Ref. ASME Sec.VIII –1, UW-51.

30. A pressure vessel was manufactured and ready for hydro test. The operating pressure is 90 psi. The MAWP is 100 psi. The hydro test pressure for this vessel shall be: There is no temperature correction a. 130 psi b. 117 psi c. 150 psi d. 135 psi Ans :

a.

Ref. ASME Sec.VIII –1, UW-99.

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API 510 CERTIFICATION PREPARATORY COURSE Practice Questions. ( Closed Book )

ASME Sec. V

1. Liquid penetrant inspection can find which type of discontinuity? 1.

Internal cracking of welds.

2.

Cracks open to the surface.

3.

Subsurface porosity.

4.

Laminations on the surfaces of plate.

Ans. 2. Ref. ASME V . T-620 2. Certification of contaminants shall be obtained for all PT materials used on 1. Carbon steels 2. Ferritic stainless steels 3. Austenitic stainless steels 4. None of the above Ans. 2. Ref. ASME V . T-640 3. The scope of the ASME Boiler and Pressure Vessel, Code, Section V includes: A. NDE acceptance criteria B. NDE metod and procedures to perform NDE C. Extent of NDE ( i.e. what welds to examine ) D. All of above Ans. B. Ref. ASME V . T-110 260

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4. For Ammeter calibration for Magnetising equipment , The allowable tolarence is:

a.

+ 5%

b.

+ 10 %

c.

+ 15 %

d.

+ 20

Ans. b.. Ref. ASME V . T-761

5. The basic features section V focuses on for any NDT technique is a.

Qualification of personnel

b.

Calibration of NDE equipments

c.

Correct procedure for NDE

d.

All of the above

Ans. c. Ref. ASME V . T-110 6. In the radiography, penetrameter is put on the job to : a.

Evaluate the image quality of the radiograph.

b.

Measure the strength of the penetrating radiation.

c.

Check the density of the radiograph.

d.

All of above.

Ans. a . Ref. ASME V . T-640

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7. Describe how a liquid penetrant examination should be performed in order to detect discontinuities, which are open to the surface :-

(a) clean the part, apply the developer, apply the penetrant, remove excess penetrant, inspect the part, clean the part; (b) clean the part, apply the penetrant, remove excess penetrant, apply the developer, inspect the part, clean the part; (c) clean the part, apply the developer, apply the penetrant, inspect the part, remove excess penetrant, clean the part; (d) clean the part, apply the developer, apply the penetrant, inspect the part, clean the part.

Ans : (b)

Ref. : ASME Sec. V-T620

What it the minimum permitted density of radiographic film using an Iridium source ?

(a) 2.0;

(b) 1.8;

(c) 1.3;

(d) 4.0

Ans. a. Ref. ASME V . T-282

8. When reviewing a radiograph, a light image of the letter B can be seen on the film (a) This is cause for rejection; (b) This is not cause for rejection; (c) This is the same as a light letter B (d) An unusual safety hazard existed during the exposure. Ans. a.. Ref. ASME V . T-284 9. The accuracy of a piece of magnetizing equipment that is equipped with an ammeter shall be verified : a. Each year b. Each two years c, When possible d. Every 6 months Ans. a.. Ref. ASME V . T-761 262

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10. How shall Non-destrutive Examination Personnel be qualified? e. To SNT-TC 1A f.

To CP-189

g. To referencing code requirements h. To ACCP rules Ans. a.. Ref. ASME V . T-284 11. For MT examination by Prod technique the spacing between prods shall be between a. 4 inch to 12 inch b. 4 inch to 10 inch c. 3 inch to 10 inch d. 3 inch to 8 inch Ans. d.. Ref. ASME V . T-752.3 13. What is the difference between an inspection and an examination per Section V of the ASME Code? a. Inspection performed AI b. Examination performed by manufacturer's personnel c. There is no difference between the two d. Both a and b, above Ans. d... Ref. ASME V . T-170 14. In pulse –echo contact method, When does a considerable Vee - error will result while measuring thickness? a.

Thickness measurement on thin sections using Dual Crystal probe

b. . Thickness measurement on thick sections using Dual Crystal probe c. . Thickness measurement on thin sections using sinlgle Crystal probe d. . Thickness measurement on thin sections using single Crystal probe Ans. a.. Ref. ASME V . Art. 23. 7.3

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15. In pulse –echo contact method which disply of UT results is recommended when reflecting surface is rough.

a.

CRT display

b.

Direct Digital display

c.

Any of a or b are OK

d.

UT is prohibited when reflecting surface is rough

Ans. a.. Ref. ASME V . Art. 23. 8.8

264

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API 510 CERTIFICATION PREPARATORY COURSE Practice Questions. (Closed Book)

ASME Sec. IX 1. Essential variable on a welding procedure specification are :(a) those in which a change, as described in the specific variables, is considered to affect the mechanical properties of the weldment; (b) those in which a change, as described in the specific variables, is considered not to affect the mechanical properties of the weldment; (c) . both (a) and (b) above are essential variables (d) They are applicable only if Impact testing of weld is specified. ANS : (c)

REF : Section IX, QW 251.2

2. The Heat Affected Zone is :(a) that portion of the base metal which has not been melted; (b) whose mechanical properties or micro structures have been altered by the heat of welding; (c) is least likely to contain discontinuities; (d) both (a) and (b) above. ANS : (d)

REF : Section IX, QW-492

3. A welder may deviate from the parameters specified in WPS if they are nonessential variables :(a) Provided the change is documented on revised WPS; (b) Provided the supporting PQR is also revised; (c) No; (d) Nonessential variables only apply to PQRs Ans. a REF : Section IX, QW-200.1

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5. A welder is a qualified welder but gives consistently defective weld. What will be your action as a Quality Control Manager?

Cut his salary to compensate your cost. Remove him from your company Discontinue him from the job and retrain and re-qualify him as per code requirements. d.

Do not worry as anyway he is only going to repair his work. Ans c.

REF : Section IX, QW-322

5. Tensile test was carried out for qualifying a welding procedure (PQR). The specified minimum tensile strength of the base metal is 70,000 psi. If the test specimen breaks in parent metal (outside weld and fusion zone) and the tensile strength calculated is 68,000 psi. a.

the test is acceptable

b.

the test is rejected

c.

the test is void and fresh test plate should be welded.

d.

none of the above Ans a.

REF : Section IX, QW-151.1

6. A weld procedure is qualified in 1G position. This procedure can be used for welding in _______ positions a.

1G

b.

2G

c.

4G

d.

all of the above

Ans d.

REF : Section IX, QW- 203

7. Guided bend test are used to determine the a.

ultimate tensile strength of the weld joint

b.

degree of soundness of fillet welds

c.

notch toughness of weldment

d.

degree of soundness and ductility of groove weld joints Ans d.

REF : Section IX, QW- 141 266

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8. When radiographic testing is used in place of bend tests in welder’s performance qualification on groove welds on plate, the minimum length of spot to be exposed is :

6” 12” 15” d.

Radiography can not be used for welder qualification

Ans a.

REF : Section IX, QW- 302.2

9. When a tensile specimen breaks in the base metal outside of the weld or fusion line, the strength recorded may be at most ____ below the specified tensile and be accepted. A.

3.5%

B.

0.5%

C.

5%

D.

All of the above Ans C.

REF : Section IX, QW- 153

10. The basic purpose of testing a welder is to establish the welder’s a. Knowledge of welding requirements b. Ability to deposit sound weld metal c..

Mechanical ability to operate equipment

d.. General attitude toward welding inspectors Ans b.

REF : Section IX, QW- 100.2

11. What is the number of transverse guided bend tests required for Performance Qualification in a 6G position? a. 2 Ans c.

b. 3

c. 4

d. 6

REF : Section IX, QW- 302.3

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12. The procedure qualification test is used to determine: a. The skill of the welder b. That the proposed production weldment is capable of having the required properties c..The corrosion-resistance of the proposed weldment d.. None of the above Ans b.

REF : Section IX, QW- 100.1

12. What period of inactivity from a given welding process requires the welder to re-qualify in that process? a. 3 months b. 6 months c. 9 months d. 12 months Ans b.

REF : Section IX, QW- 322.1

13. Groove weld test may be used for qualification of welders. Which of the following shall be used for evaluation? a. Only bend tests b. Only radiography c. Both radiography and bend tests d. Either bend tests or radiography Ans d.

REF : Section IX, QW- 300.1

14. Under which of the following conditions can a welder be qualified during production work? a. A 6” length of the first production groove weld may be qualified by radiography b..A bend test coupon may be cut from the first 12” length of weld c. .A macro examination may be taken from the first 3” of weld length d. None of the above Ans a.

REF : Section IX, QW- 300.1 268

IET/CH/TP/002-R2, Sept. 11

API 510 CERTIFICATION PREPARATORY COURSE Practice Questions. (Open Book)

ASME Sec. VIII Div.1 1. A spot radiograph of a butt weld in a 1 inch thick shell of a vessel marked RT3 was found to have a rounded indication, the dimension of such an indication according to Section VIII Div. 1 is; 1. 1/32 of an inch. 2. 1/3 of an inch. 3. 2/3 of an inch 4. None, rounded indications are not a consideration with spot radiography. Ans. 4.

Ref. ASME Sec. VIII Div.1. UW-52.

2. A vessel having nominal thickness 1” (P No.1 Group No. 1) post weld heat treated with normal holding temperature 11000 F minimum will require a holding time of a.

1 hour minimum

b.

1 hour maximum

c.

15 minutes minimum

d.

None of the above

Ans. a.

Ref. ASME Sec. VIII Div.1. UW-56.

3. Compared to ASTM A 515 Gr. 60 plates, ASTM A 516 Gr. 60 plates have: a.

Better Tensile Strength

b.

Better toughness

c.

Better high temp. properties

d.

None of above Ans. b.

Ref. ASME Sec. VIII Div.1. UW-57.

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4. The length of a charpy specimen is: a. 2.165” (55.0mm) b. 2.10” (54.0 mm) c. 2.15” (54.6 mm) d. 2.00” (50.8mm) Ans. a.

Ref. ASME Sec. VIII Div.1. UG-84.

5. A 1” thickness plate was joined with 1 ½” plate with a groove weld to make a torispherical dish to shell joint. The allowable misalignment for the joint shall be: 1. ¼” 2. 3/16” 3. 5/16” 4. 1/8” Ans. 2.

Ref. ASME Sec. VIII Div.1. UW-33.

6. What weld reinforcement is allowed on longitudinal weld made on the 1” thick shell a. 3/32 “ Ans. a.

b. 1/8”

c ¼”

d. 3/16”

Ref. ASME Sec. VIII Div.1. UW-35.

7. Which of the following liquid penetrant indications would be unacceptable? A.

Relevant linear indications

B.

Relevant rounded indications greater than 3/16"

C.

Four or more relevant rounded indications in a line separated by 1/16" or less

D.

All of the above Ans. D.

Ref. ASME Sec. VIII Div.1. App.8.

8. A vessel nameplate is stamped RT 4 this indicates that: A.

The complete vessel has not satisfied the radiographic requirements of B, C, D below

B.

The complete vessel meets the requirements of UW-11(a)(5) and the spot radiography requirements of UW-1 (a )(5)(b) have been applied

C.

All butt welds have been 100% radiographed

D.

All butt welds have been spot radiographed per UW-52 Ans. A.

Ref. ASME Sec. VIII Div.1. UG-116. 270

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9. P-No. 1, Group 1 or 2 material listed on Curve A is exempted from impact testing if it does not exceed A.

1 in.

B.

2 in.

C.

1/2 in.

D.

9/16 in.

Ans. C.

Ref. ASME Sec. VIII Div.1. UG-20 f .

10. You are to impact test a material, which is 1 in. thick, and has a minimum specified yield strength of 55 ksi. What is the required average for the 3 specimens? A.

20 ft-lbf

B.

l5 ft-lbf

C.

30 ft-lbf

D.

50 ft-lbf

Ans. A.

Ref. ASME Sec. VIII Div.1. Fig. UG-84.1

11. Ultrasonic examination in accordance with UW-53 may be substituted for radiography for what condition? A.

It is never permitted

B.

When radiographic equipment is not available

C.

For the final closure seam if the construction does not permit interpretable radioqraphs

D.

For longitudinal welds when they are in excess of 1 1/4 in. Ans. C.

Ref. ASME Sec. VIII Div.1. UW-11a.

12. A pressure vessel, which is 50 in. inside diameter, has a flat spot. What is the maximum permitted out of roundness at this location? A.

2.00 in.

B.

1.00 in.

C.

0.750 in.

D.

0.500 in. Ans. D.

Ref. ASME Sec. VIII Div.1. UG-80. 271

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13. Surface weld metal buildup is required to be examined over the full surface of the deposit by which of the following?

A.

Radiographic

B.

Ultrasonic

C.

Magnetic Particle

D.

Acid etching Ans. C.

Ref. ASME Sec. VIII Div.1. UW-42.

14. The temperature of the furnace shall not exceed _____0F at the time the vessel or part is placed in it.

A.

600

B.

500

C.

800

D.

300

Ans. C.

Ref. ASME Sec. VIII Div.1. UCS-56d.

15. According to the ASME Code, Section VIII, the metal temperature during pneumatic test shall be at least _____ above the minimum design metal temperature to minimize the risk of brittle fracture. A.

200F

B.

300F

C.

400F

D.

500F Ans. B.

Ref. ASME Sec. VIII Div.1. UG-100.

16. If a vessel is so large that it must be PWHT in more than one heat, what is the minimum overlap in the furnace? A.

5’

B.

10'

C.

3' 272

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D.

2' Ans. A.

Ref. ASME Sec. VIII Div.1. UW-40.

17. The angle and radius of notch for the impact test specimen specified by the code is a.

450 angle 0.010” radius

b.

900 angle 0.010” radius

c.

450 angle 0.394” radius

d.

any one will do as it is going to break only

Ans. A.

Ref. ASME Sec. VIII Div.1. Fig. UG-84.

18. Above 8000F the heating rate shall not be more than ______ 5000F/hour divided by the maximum metal thickness

A. B.

4000F/hour divided by the maximum metal thickness

C.

9000F/hour divided by the maximum metal thickness

D.

2000F/hour divided by the maximum metal thickness

Ans. B.

Ref. ASME Sec. VIII Div.1. UCS-56 d.

19. Above 8000F the cooling rate shall not be more than A.

5000F/hour divided by the maximum metal thickness

B.

4000F/hour divided by the maximum metal thickness

C.

9000F/hour divided by the maximum metal thickness

D.

2000F/hour divided by the maximum metal thickness

Ans. A.

Ref. ASME Sec. VIII Div.1. UCS-56d.

20. What is the minimum holding time for a P-No. 3 Group 2 welded joint 6 in. thick? A.

3 hours

B.

3 hours 30 minutes

C.

2 hours

D.

5 hours

Ans. A.

Ref. ASME Sec. VIII Div.1. Table UCS-56. 273

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API 510 CERTIFICATION PREPARATORY COURSE Practice Questions. (Open Book)

ASME Sec. V 1. The recommended minimum development time allowed for a material made of high temperature alloy is

a. 5 min b. 10 min c. 7 min d. 60 min

Ans: b.

Referance ASME Sec. V Art.6

2. What is the geometric unsharpness allowed as per code for a thickness of 2.0” (50.8 mm) as per code? a. 0.020” ( 0.508mm) b. 0.030” (.00.762mm) c. 0.010 (0.254mm) d. None of the above

Ans: b.

Referance ASME Sec. V Art.2, table 276

3. For steel plates and welds to be checked by LPI, what shall be the penetration time for Penetrant a) 10 min for weld, 5 min for plate b) 5 min for both c) 10 min for both d) 5 min for weld, 10 min for plate Ans: d.

Referance ASME Sec. V Art.6

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4. A 1” thickness butt weld has 0.125” acceptable reinforcement was radiographed. The applicable plate type penetrameter on (Film side) and essential hole shall be

a.

ASME 30 - 2T

b.

ASME 25 - 2T

c.

ASME 20 - 2T

d.

ASME 30 - 4T Ans: b.

Referance ASME Sec. V Art2, table 276

5. What weight shall be used to check adequacy of lifting power of a permanent magnet yoke. ? (a) 10 pounds Ans: d.

(b) 20;pounds c) 30 pounds

(d) 40 pounds.

Referance ASME Sec. V Art.7

6. When should a densitometer be calibrated as a minimum? a. Annually b. Every 90 days c. Whenever it is turned on d. As required by the Examiner Ans: b.

Referance ASME Sec. V Art.2

8. In puse –echo UT technique, calibration was done at 100 deg. F. Thickness measurement at 700 deg. F showed trading of 50 mm. After temperature correction what is correct thickness? a. 48 mm b. 47mm c. 53mm d. 52mm Ans: b.

Referance : ASME Sec. V Art.23, 8.5

9. What wire No. shall make image on the film If type of penetrameter is wire type which was put source side . Nominal single wall thickness is 0.875 inch and permissible reiforcement is 0.125 inch. (wire decimeter in inch) 1.

0.025 (No. 10)

2.

0.016 (No. 8) 275

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Ans: 3. 10.

3.

0.020 (No. 9)

4.

None of the above

Referance : ASME Sec. V Art.2.

After applying the developer the examiner checked four welds by PT after following period, weld A - 7 minutes, weld B - 15 minutes, weld C - 25 minutes and welds D - 70 minutes. Which of the welds were checked with incorrect interpretation time? a.

A and B

b.

B and C

c.

C and D

d.

A and D

Ans: d.

Referance : ASME Sec. V Art.6

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API 510 CERTIFICATION PREPARATORY COURSE Practice Questions. (Open Book)

ASME Sec. IX 1. A welder is decided to be qualified on his initial production weld on 1/4” thick longitudinal seam of carbon steel shell. The first 6” length of the weld was radiographed. The radiograph reveals slag length of 5 mm. Your decision in this case will be a.

welder is not qualified .

b.

welder is qualified since he meets acceptance criteria of ASME sec. VIII Div.1

c.

Data not adequate. In addition to radiography, bend tests are required.

d.

Data not adequate. In addition to radiography, tension tests are required.

Ans: a.

Referance : ASME Sec. IX, QW 191.2.1

2. In a certain PQR for SMAW, the electrodes used for all passes were of AWS classification (E 7018). Corresponding WPS also showed filler materials as E 7018. Now the manufacturer proposes to change the filler material in WPS to E 7015. Will you ask manufacturer to: a. Quality new PQR with E 7015 electrodes. b. Revise only WPS showing the change from E 7018 to E 7015 and submit WPS as a new revision. c. Revise only the PQR document showing the change and resubmit for approval. d. Revise both WPS and PQR showing the change and resubmit for approval

Ans: b..

Referance : ASME Sec. IX, and Table QW-253.

3. What positions are necessary to qualify a welder for all position pipe welding? E.

3G and 4G 277

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F.

2G and 5G

G.

3G and 1G

H.

4G and 5G

Ans: b.

Referance : ASME Sec. IX, QW Table 461.9

4. The maximum preheat temperature decrease allowed without requalification of a GMAW groove weld procedure is: a

500F

b. 1000F c. 1250F d. 1500F

Ans: b.

Referance : ASME Sec. IX, table QW 355

5. The P numbers are assigned on the basis of a. Hardness b. Composition, weldability & mechanical properties c. Ductility only d. None of the above Ans: b.

Referance : ASME Sec. IX, QW-420

6. A groove weld was made with 1 ¼” thickness plate with SMAW process for PQR Qualification and the test were found acceptable. This PQR can be used up to a maximum weld thickness of: a. 1 ¼” b. 2.5” c. 8” d. None of the above Ans: b.

Referance : ASME Sec. IX, QW 451

7. A welder qualifies in the 3G position on a plate coupon, he is then qualified to weld in the position(s) on NPS 6 pipe :(a) F, V; (b) F only; 278

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(c) F, V, O; (d) ALL

Ans: b.

Referance : ASME Sec. IX, QW 461.9

8. A welder who gave procedure test in 3G position is also qualified for performance in (a) 3G and 1G (b) 1G only (c) None. Procedure does not qualify performane. (d) must requalify (e) All positions Ans: a.

Referance : ASME Sec. IX, QW 203

9. A welding procedure qualified on ¼ inch thick plate can be used to weld groove welds in materials from to :(a) 3/16 to 3/4;

(b) 1/16 to 3/4;

(c) 3/8 to 3/4;

(d) 1/16 to 1/2.

Ans: d.

Referance : ASME Sec. IX, QW 451.1

10. E7018 electrodes are classified as F number :-

Ans: c.

a

1;

b

2;

c

4;

d

5.

Referance : ASME Sec. IX, QW 432

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API 510- INSERVICE PRESSURE VESSEL INSPECTOR PREPARATORY COURSE

PART X

QUESTION BANK QUESTIONS ON RECOMMENDED PRACTICES

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API 510 CERTIFICATION PREPARATORY COURSE QUESTIONS ON RECOMMENDED PRACTICE (CLOSED BOOK)

API RP576 - Inspection of Pressure relief Devices: 1.

2.

Where (typically) are balanced safety relief valves used in refineries?

a.

In general refinery service for gas, vapour, steam, air or liquids

b.

In corrosive refinery service

c.

When the discharge from the valves must be piped to remote points

d.

All of the above

Which of the following are possible reasons for improper performance of valves?

3.

a.

Corrosion

b.

Damaged seating surfaces

c.

Failed springs

d.

All of the above

Which of the following tests must be conducted on a valve as soon as it has been removed out of a system and taken to repair shop?

4.

a.

Visual inspection

b.

Dye penetrant testing

c.

As received pop-pressure

d.

As received leak test

Which of the following codes of practice deals with safety valves on power boilers? a.

ASME Section I

b.

ASME Section IV 281

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.

c.

ASME Section VIII, Div. 1

d.

ASME Section VII

5. Which of the following best describes a safety relief valve? a.

A spring – loaded pressure relieving device that is popped open by enough static pressure in the huddling chamber and kinetic energy of the gas or vapour to overcome the spring force on the disc as it lifted to provide full opening and allow minimal overpressure.

b.

A spring – loaded pressure relieving valve that acts as a safety valve when used in gas or vapour service and as a relief valve when used in liquid service.

c.

A spring – loaded pressure relieving device for liquid service that begins to open when the inlet pressure reaches set pressure. Overcomes the spring force and begins to lift the disc off the seat and that continues to open as inlet pressure and the lift of the disc increase allowing the flow of the liquid to increase.

d. 6.

7.

8.

All of the above

“Blow down” means difference between: a.

Discharge pressure and set-pressure

b.

Set-pressure and back pressure

c.

Set-pressure and closing pressure

d.

Set-pressure and operating pressure

“Car seal” is: a.

Used on safety relief valves (SRV) for over pressure protection

b.

Used on SRVs for protection against excessive temperature

c.

Locking seal which must be cut or broken for removal

d.

Used for avoiding theft of the car

Which of the following statements is / are true as regards conventional safety relief valve? a.

It is used on gases

b.

It is used only on liquids

c.

Its operation is affected by back pressure

d.

It must be used along with a rupture disc 282

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9.

Which of the following are reasons for inspection of pressure-relieving devices?

10.

a.

To protect personnel and equipment

b.

To determine the condition of a device

c.

To evaluate process upsets

d.

Only “a” and “b” above

The discharge from safety relief valves is highly corrosive product and it needs to be piped to remote location. Which of the following pressure relief device will you use?

11.

12.

a.

Use pilot-operated safety relief valve

b.

Use conventional safety relief valve

c.

Use balanced safety relief valve

d.

Use rupture disc instead of the safety relief valve

What is the typical shape of an impervious graphite rupture disc? a.

Flat

b.

Concave to the pressure side

c.

Convex to the pressure side

d.

None of the above

Which of the following is true as regards the use of reverse-acting rupture disc? a.

For same bursting pressure, they can be used for higher operating pressures than conventional type of same rating

13.

b.

They cannot be used for corrosive service

c.

They are installed concave to pressure disc

d.

All of the above

After removal from service, the pressure relief valves should be shipped to the shop in: a.

Horizontal position

b.

Upright position

c.

Any position

d.

Dismantled position

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14.

15.

16.

Failed springs in pressure relief valves are almost always caused by? a.

Surface corrosion and stress corrosion cracking

b.

Graphitization

c.

Tensile failure

d.

All of the above

Which of the following could cause chatter (hammer) in valves? a.

Improperly supported or length piping to the valve inlet

b.

Obstructions in the line

c.

Erosion

d.

Only “a” and “b”

API 576 does not address: a.

Inspection of control valves

b.

Application of manually operated relief devices

c.

Training requirements for mechanics involved in inspection and repair of pressure relieving devices

d.

All of the above

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ANSWER KEY-API 576.

Question No.

Answer

1

c

2

d

3

c

4

a

5

b

6

c

7

c

8

c

9

d

10

c

11

a

12

a

13

b

14

a

15

d

16

d

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API 510 CERTIFICATION PREPARATORY COURSE Practice Questions. (Closed Book) QUESTIONS ON API RECOMMENDED PRACTICES

API RP 571 Damage Mechanisms :

Q.1 Temper embrittlement typically takes place with which of the following materials: a. Austenitic Stainless steels b. Carbon Steels c. Low alloy steels containing Chromium d. Duplex Stainless Steels

Ans:

c

Reference : API RP 571

4.2.3

Q.2 Brittle fracture typically takes place with which of the following materials: a. Austenitic Stainless steels b. Carbon Steels c. Low alloy steels d. Both b and c

Ans:

c

Reference : API RP 571

4.2.7

Q.3 which of the following is true for Thermal fatigue : a. It is caused due to Stress concentration and thermal cycling b. It is caused at welds where materials with differing thermal exansion coefficint are welded c. They are Dagger shaped, oxide filled and initiate form the surface. d. All of above. Ans:

d

Reference : API RP 571

4.2.9

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Q.4 Erosion/Corrosion can be controlled by : a. Increasing the pipe diameter to decrease velocity b. Increasing surface hardness by using harder alloys or hard facing c. Using corrosion resistant alloys d. All of the above. Ans:

d

Reference : API RP 571

4.2.14

Q.5 “Clam shell” type cracking failure is typically found in: a. Mechanical fatigue. b. Creep failure. c. Stress corrosion cracks. d. Hydrogen induced cracks. Ans:

a

Reference : API RP 571

4.2.16

Q.6 which of the following is true for Atmospheric corrosion a. It increases in marine environment. b. It causes environmental cracks in Carbon steels c. It reduces in dry rural environment. d. Only a and c Ans:

d

Reference : API RP 571

4.3.2

Q.7. Cooling water corrosion increases with: a. Increases with high flow velocity or turbulence. b. Increases with stagnant or low velocity flow. c. Increases with high dissolved oxygen d. Only b and c Ans:

d

Reference : API RP 571 4.3.4

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Q.8. The dissolved gases which cause Boiler water condensate corrosion are: a. Oxygen and Hydrogen b. Hydrogen and Carbon di oxide c. Chlorine and Hydrogen d. Oxygen and Hydrgen Ans:

d

Reference : API RP 571 4.3.5

Q. 9 What construction material will you suggest where you are expecting serious Sulphidation problem. a. Upgrade to higher nickel alloys b. Upgrade to higher chromium alloys c. Upgrading to higher copper based alloys d. All of the above. Ans:

b

Reference : API RP 571 4.4.2

Q.10 Characteristic of Chloride SCC in Austenitic S.S. is: Cracks which are: a. Transgranular, branching and aggravated at elevated temperature b. Intergranular and unidirectional (straight) c. Independent of chloride content d. None of the above Ans:

a

Reference : API RP 571 4.2.3

Q.11 Identify the correct statement (s) a. SSC is aggravated due to wet H2S b. Hydrogen blistering may occur on I.D, O.D, or any where within wall thickness of the pressure vessel. c. High hardness & High strength steels are more likely to undergo damage due to wet H2S compared to low strength/ low hardness steels d. All of the above are correct statements Ans:

c

Reference : API RP 571 4.5.1

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Q.12 High temperature hydrogen attack is typically due to a. Methane gas formation. b. Wet H2S c. Creep rupture d. Presence of Nickel in alloy steels. Ans:

a

Reference : API RP 571 5.1.3.1

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QUESTIONS ON API RECOMMENDED PRACTICES API RP 572 – Inspection of Pressure Vessels:

1)

If any setting is noticed on a vessel, which of the following should be done a. Conduct RT after 48 hours of observing the defective condition b. Nozzles and adjacent shell areas should be inspected for distortion and cracking c. Use acoustic emission monitoring d. All of the above Ans:

b

Reference : API RP 572

2) Which of the following are typical conditions found on the external surfaces of aboveground vessels? a) CUI for insulated vessels b) Atmospheric corrosion c) Soil corrosion d) Only “b” and “a” above Ans:

d

Reference : API RP 572

3) The platform and ladder should inspected by a. Visual check b. Hammer tapping c. Acoustic emission check d. Only “b” and “a” above Ans:

d

Reference : API RP 572

4) Which of the following are types of corrosion monitoring techniques

Ans:

d

a.

Depth drilling

b.

Corrosion buttons

c.

None of a and b

d.

Both “a” and “b” Reference : API RP 572

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5) The type of surface preparation required for internal inspection depends on a. The type of deterioration expected b. Time available for inspection c. Age of Vessel d.

“a” and “c”

Ans:

a

Reference : API RP 572

6) How many tube sheets would a heat exchanger have which incorporates Utubes in it? a. One b. Two c. Three d. None of the above Ans:

a

Reference : API RP 572-General Knowledge.

7) Erosion would normally be exhibited at .. a. Elbows b. Downstream of control valves c. Downstream of orifices d. All of the above Ans:

d

Reference : API RP 572

8) How is hammer testing utilized? a. As a supplement to visual inspection b. As a independent test method for which ASNT Certification in NDT is available c. As a cross-check to UT measurement d. All of above Ans:

a

Reference : API RP 572

9) Scheduling of refinery shutdowns for maintenance or inspection is usually arranged as per Inspection intervals a.

Given by API 510

b.

Set by Jurisdiction 291

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c. Set by RBI studies d.

Ans:

d

Any of above.

Reference : API RP 572

10) Shells of vessels adjacent to inlet impingement plates are susceptible to a. Microbiological corrosion b. Erosion c. Hydrogen embrittlement d. Oxydation Ans:

b

Reference : API RP 572

11) Which of the following are common reasons for in- service of shutdown inspection a. To determine the physical condition of he equipment b. To determine the type, rate and causes of deterioration c. none of the above d. “a” and “b” above Ans: d

Reference : API RP 572

12) Which of the following are commonly used techniques of surface preparation for inspection a. Wire brushing b. Sand – blasting c. High pressure water blasting d. All of the above Ans:

d

Reference : API RP 572

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API RP 576 Inspection of Pressure Relief devices:

1) Indicate the application where typically balanced safety relief valves used in refineries? a) In a clean , non-corrosive liquid or gas service b) In pressures above 100 psi. c) When the discharge from the valves must be piped to remote locations d) Only in liquid service Ans:

c

Reference : API RP 576

2) Which of the following are possible reasons for improper performance of valves? a) Corrosion and plugging of valves b) Chattering and damaged seating surfaces c) Breakage of springs d) All of the above Ans:

d

Reference : API RP 576

3) Which of the following tests must be conducted on a valve as soon as it has been received in the testing shop a) As-received Visual Inspection b) As-received leak test with water bubble method c) As-received pop-pressure d) As-received discharge capacity

Ans:

c

Reference : API RP 576

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4) “Reverse Rupture disc” means a rupture disc with a) Bursting pressure acting on concave side b) Bursting pressure acting on convex side c) Bursting pressure acting on flat surface d) All of the above Ans:

b

Reference : API RP 576

5) Which of the following could cause chatter in valves? a) Excessively long length piping to the valve inlet. b) Obstructions in the inlet line c) Erosion d) Only “a” and “b” Ans:

d

Reference : API RP 576

6) API 576 does not address a) Rupture disk devices b) Inspection of automatic operating pr. relieving devices c) Training requirements for mechanics involved in inspection and repair of pressure relieving devices d) Only a and c Ans: 7)

c

Reference : API RP 576

After reconditioning and reassembly, following 3 valves, each having set pressure= 60 psi were tested for for pop pressure. The pop pressures noted were 62 psi, 59 psi, 57 psi. How many valves will you accept as within tolerance? a. 2 b. 1 c. All 3 d. None Ans:

a

Reference : API RP 576 294

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8) What is the pressure at which Leak-check should be performed If CDTP of a Safety Relief Valve is 150 psi

a. 130 psi b. 135 psi c. 150 psi d. 160 psi Ans: b

Reference : API RP 576

9) As per API 576, What is the maximum inspection interval for Visual On- stream inspection

a.

3 years

b.

1 year

c. 5 years d. 10 years Ans: c

Reference : API RP 576

10) After reconditioning and reassembly, following 3 valves, each having set pressure= 200 psi were tested for for pop pressure. The pop pressures noted were 195 psi, 202 psi, 206 psi. How many valves will you accept as within tolerance? a.

1

b. 2 c.

3

d.

All 3

Ans:

d

Reference : API RP 576

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API RP 577- Welding and Metallurgy:

1. If Coated electrodes and fluxes become wet, What should be done. a. Dry the Coated electrodes and carry out oven baking to ensure they are completely dry before re-using b. Dry the Fluxes and carry out oven baking to ensure they are completely dry before re-using c.

Both a and b.

d. discard them Ans:

d

Reference : API RP 577

2. A radiograph shows slag inclusion linear indication of length 19 mm. Acceptable length is 12 mm. This indication can be classified as: a Recordable indication b

Reportable indication

c

both a and b

d

None of above Ans:

c.

Reference : API RP 577

3. For carbon steel welding, Heat affected Zone typically means: a. Zone adjacent to the weld which is not melted b. Has its properties or microstructure altered c. Was heated to more than 700 deg.F d. All of above Ans:

d

Reference : API RP 577

4. A sub –surface terrace and step-like crack with basic orientation parallel to the base metal surface caused by tensile stresses normal to thickness direction is called a. Lamination b. Step-wise cracking c. Lamellar tearing d. Stress corrosion crack Ans:

c

Reference : API RP 577 296

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5.

The “Slag inclusion” is typically not found in welding performed by a.

SMAW

b.

c and d below

c

GTAW

d

GMAW Ans:

b

Reference : API RP 577

6. Most applicable method for Performance qualification of welders as per ASME Sec. IX for GMAW-S process is:

a. Radiography only b. Bend tests only c. Either radiography or bend tests d. Both Radiography and bend tests Ans:

b

Reference : API RP 577

7. For direct visual examination, accessibility of eye shall be:

a. within 6” – 24” with angle less than 30° with the surface b. within 6”- 24”with angle not less than 30° with surface c. within 24” with angle less than 30° d. beyond 24”with angle not less than 30° Ans: 8.

b

Reference : API RP 577

A perfectly clear radiography film indicates film density of

a. 4 Ans:

c

b. 1.

c Zero

d. 2

Reference : API RP 577

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9.

B-scan In UT examination didplays:: a. cross-sectional elevation view of object scanned. b. Plan view of object scanned c. Pulse –Echo view d. None of above Ans:

10.

a

Reference : API RP 577

Steels with CE greater than 0.55% typically require: a. Preheating only b. Pre-heating & PWHT c. No pre- heating or PWHT d. PWHT only Ans:

b

Reference : API RP 577

11. Simplest Weldability tests are those that evaluate a. Strength and Ductility of the weld b. Strength and hardnedd of the weld c. Strength and toughness of the weld d. Toughness and Ductility of the weld Ans:

a

Reference : API RP 577

12. A method to assure that PWHT on the welds was performed satisfactorily is to perform which of the following after PWHT a. Hardness testing of weld & HAZ b. Radiography of weld &HAZ c. Calibrate Thermocouples d. UT of weld & haz Ans:

a

Reference : API RP 577

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13.

Among the following Welding processes, identify the one that has highest metal deposition rate

a. all of below. b. GTAW followed by SMAW c. GMAW d. SAW Ans:

d

Reference : API RP 577

14. A welding process which allows welding to be done without adding filler metal is

a. SMAw b. GTAW c. GMAW d. FCAW Ans:

b

Reference : API RP 577

15. As hardness of Heat affected zone increases -------

a. Susceptibility of Hydrogen assisted Cracking increases. b. Susceptibility of Hydrogen assisted Cracking decreases c. Tensile Strength of the weld decreases d. All of above Ans:

a

Reference : API RP 577

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