Ge. Gek81515d. Flushing Procedure For Turbine Lube Oil System. Oct-2003

GEK 81515D Revised, October 2000 Last Reviewed, October 2003

GE Power Systems

Flushing Procedure for Turbine Lube Oil System

These instructions do not purport to cover all details or variations in equipment nor to provide for every possible contingency to be met in connection with installation, operation or maintenance. Should further information be desired or should particular problems arise which are not covered sufficiently for the purchaser’s purposes the matter should be referred to the GE Company. © 1991 General Electric Company

GEK 81515D

Flushing Procedure for Turbine Lube Oil System TABLE OF CONTENTS

I. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. B. C. D. E.

General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Written Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . System Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pipe Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Piping Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3 3 3 4 4

II. PREPARATION FOR FLUSHING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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A. B. C. D. E. F. G. H. J. K. L. M. N.

Supplemental Pump and Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vibrating Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Shell and Tube Oil Coolers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lube Oil Pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Main Oil Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Optional In–Line Oil Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Standards and Bearing Housings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Liquid Level Detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Turning Gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seal Oil Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Turbine and Generator Bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Miscellaneous Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4 5 5 5 5 5 6 6 6 6 6 7 7

III. FLUSHING PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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A. B. C. D. E. F. G. H. J.

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3

Oil Tank Filling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Coarse Flush . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sequential Flush . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . System Clean Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Securing the Flush . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Termination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Acceptance Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Allowable Contamination Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Strainer Basket Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Flushing Procedure for Turbine Lube Oil System

GEK 81515D

I. INTRODUCTION A. GENERAL INFORMATION It is neither practicable nor economical to utilize a step–by–step procedure written to cover various types of turbine–generators being constructed under a wide variety of jobsite conditions. It is the responsibility of the General Electric Company Field Representative to evaluate such things as the condition of the piping system, the installation schedule, the financial aspects of the customer and his agents; and assist all the involved parties in planning an oil flush which will result in a clean system. A long costly oil flush can be avoided if a program is set up early to assure the following criteria are met: 1. Piping is properly pickled and protected upon receipt at the jobsite. 2. Piping is stored in a clean and dry environment and not allowed to deteriorate prior to installation. 3. Piping is installed in a manner which allows minimum entry of foreign material. 4. Piping is adequately oil flushed. 5. Cleanliness of system maintained until initial operation. The following article contains the general recommendations for flushing the lube oil system. B. WRITTEN PROCEDURE General Electric Company practices and recommendations should be reviewed with the owner and his agents. At this time, the owner may elect to outline in writing details of the flushing operation. The written procedure is recommended as it will serve to outline the requirements and responsibilities of all involved parties including: 1. Scheduling and manpower requirements 2. Safety considerations; fire hazards, electrical equipment “tag out” procedures, etc. 3. Setup, flushing, and securing procedures 4. Oil sampling and testing, reports, and data log 5. Acceptable cleanliness level to be achieved. C. SYSTEM DESCRIPTION The turbine lube oil system (see 879E545, Lube Oil Flushing Diagram) supplies oil to the turbine and generator journal bearings, thrust bearing, turning gear and generator hydrogen seals, as well as other components which may vary on specific units. For air–cooled generators, disregard instructions concerning hydrogen seal oil system. The main oil tank contains the following components: 1. Reservoir, with drain provisions, connections for purchaser’s oil conditioning equipment and level gauge with high and low level alarm switches 2. Two shell and tube oil coolers (200% cooling capacity)

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GEK 81515D

Flushing Procedure for Turbine Lube Oil System

3. Two full capacity, vertical centrifugal oil pumps with ac motors and inlet strainers 4. One emergency vertical centrifugal oil pump with a dc motor and inlet strainer 5. Bearing pressure regulating valve 6. Motor–driven vapor extractor and lube oil mist separator in reservoir 7. Selector valve, to provide oil to generator shaft seals to maintain hydrogen gas pressure during shutdown 8. Instrument console mounted on reservoir which contains pressure switches, pump test valves, gauges, and dial thermometers. The generator hydrogen shaft sealing system is supplied by oil piped to the seal oil control unit from the main lube oil system. The seal oil control unit contains filters, differential pressure regulator, flowmeter, float trap, alarm pressure switches, and gauges. The air side seal–oil and generator bearing oil drains to the bearing drain enlargement through a loop seal and back to the main oil reservoir. The hydrogen side seal–oil drains the two seal drain enlargements through the float trap to the bearing drain enlargement. D. PIPE STORAGE GE–supplied lube oil piping will be fabricated and shipped in accordance with the “piping oil turbine and generator” drawings. The pipe will be cleaned and protected internally, exterior painted, and ends capped. Depending on size and configuration, the piping will ship boxed, loose, or as part of containerized shipment. Dry indoor storage is recommended as the protective coat will stand a limited amount of moisture exposure. Protective caps should be replaced where lost, damaged in transit, or removed for inspection. E. PIPING INSTALLATION Efforts should be made to keep foreign material from entering the system during the erection. Cap open end pipes and cover standards and oil tank openings whenever possible. Lines should be blown out with air and manually cleaned as best as possible prior to installation. The oil supply and drain lines are welded without backing rings using a butt–welding procedure. This has been done to eliminate dirt traps caused by backing rings. Lines under 2 in. (50.8 mm) will generally be socket welded. II. PREPARATION FOR FLUSHING A. SUPPLEMENTAL PUMP AND FILTER A supplemental pump is recommended as it will increase the oil flushing velocity (the single most effective element in flushing dirt). The suction of this pump should be connected at the blank flange on the tank side. This can be modified for suction size and later plugged. The turbine lube oil pumps for an EHC unit are designed to provide a normal operating flow to the bearings. Since a more effective flushing velocity is beyond the pump capacity, a supplement pump should be employed. The turbine oil pumps should not be run simultaneously with the supplementary pump. The pump should be sized to handle two to three times the rated flow of the unit. Oil pump pressure should not exceed 150 psig [1034.2 kPa (gauge)][10.5 kg/cm2 (gauge)].

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Flushing Procedure for Turbine Lube Oil System

GEK 81515D

A supplemental 10–micron nominal filter is also recommended as it reduces the amount of dirty oil being recirculated. If a bypassing type filter is used, it should be sized to handle at least 20% of system flow. The permanent station lube oil purification system, main oil tank screens, temporary bearing strainer basket, and the removal of settling dirt is adequate to remove foreign material from the system. The supplemental pump and filter will enhance the removal of dirt and decrease flushing time. Flushing and filtering skids are available from several sources that specialize in these services. GE–PGSD may be contacted for assistance in locating a skid. B. VIBRATING PIPING Vibrating and hammering the piping while circulating oil is very effective. It loosens dirt and weld beads and keeps the particles in suspension for the oil to carry it away. Any piping that has been modified on the job and all field welds and bends that can be reached with reasonable effort should be hammered with a hand held pneumatic hammer. Pneumatic vibrators that can be mounted directly to the welded joints of the piping are recommended. A good quality vibrator is a must as small electric vibrators are of little or no use. C. SHELL AND TUBE OIL COOLERS Two oil coolers are provided, each with 100% capacity. Remove one cooler bundle during the flush so that maximum flushing velocities may be obtained. The remaining cooler should have a source of hot and cold water for temperature cycling of the flushing oil. The maximum allowable water temperature is 200° F (93.3° C). At no time should the temperature difference between the oil and water be greater than 100° F (37.8° C). At the completion of the flush, remove the remaining cooler bundle so that cooler shells and bundles may be thoroughly cleaned. D. LUBE OIL PUMPS The oil pump motors on the main oil tank should be lubricated and prepared for operation as stated in the Operators Manual. The direction of rotation, amperage, and vibration should be checked immediately upon initial operation. E. MAIN OIL TANK Fine mesh screens (60 to 100 mesh) should be installed near the tank drain connection to filter the return oil. These screens may be attached to an existing baffle plate or a field–fabricated screen basket may be installed on the downcomer pipe discharge inside the distribution box. The bearing pressure reduction valve should be removed and a temporary jumper pipe installed. Should a supplemental pump be used, its discharge may be connected on the tank top in place of one of the ac pump discharge elbows. All piping inside the tank should be checked against the control diagram to be sure all connections are correct. Check all flanges and unions for tightness. The tank should be thoroughly cleaned and inspected before filling. F. OPTIONAL IN–LINE OIL FILTERS The top of the oil tank has a 180° pipe bend to allow for the addition of this optional duplex filter. A transfer valve allows either filter to be in service during turbine operation. Even though each of the two filters can handle 100% of the oil system flow, the high pressure and flow during flushing will destroy the filter elements. For this reason, when the optional in–line oil filter is used, one of these procedures should be followed.

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GEK 81515D

Flushing Procedure for Turbine Lube Oil System

1. Leave the filter in line, but remove the filter elements used for normal operation before flushing. 2. Follow the same procedure as above except to replace the removed filter with a steel mesh filter that could withstand the flushing. The disadvantage in this procedure is that the mesh size necessary is too large to be very useful. 3. The duplex filter piping could be flushed separately. By following these procedures, the filter elements will be protected. This simple precaution will save both time and money by avoiding the need to replace the filter elements. G. STANDARDS AND BEARING HOUSINGS All standards and bearing housings should be thoroughly cleaned before the flush. Temporary covers should be made and fitted so as to prevent the entry of foreign material and minimize oil splashing and vapors. H. LIQUID LEVEL DETECTORS Test the liquid level detectors for operation and alarming with oil. Should the detector alarms not be in service at the oil flush, disconnect the device completely so it will drain openly. J. TURNING GEAR The oil feed piping to this device should be disconnected as close to the turning gear as possible and piped to direct the oil into the standard. A means of shutting off the flow should be provided. K. SEAL OIL CONTROL SYSTEM Remove the ball float from the float trap. Remove the inlet filters for preliminary flushing and when the oil feed line is reasonably clean, install the filters for the remainder of the flush. Should a supplemental pump be used, remove the filters and leave them out. The oil should not be allowed to pass through the seal drain enlargement and float trap initially. The feed lines at the generator should be jumpered into a tee and valved in such a manner as to allow the oil from the feed line to be dumped via a basket strainer to the bearing drain. Only when the oil becomes sufficiently clean should it be allowed to pass through the seal drain enlargement and float trap. This arrangement will stop unnecessary contamination of the seal oil system and provides for a good dirt trap and monitoring station at the strainer basket. L. TURBINE AND GENERATOR BEARINGS The No. 1 and thrust bearings (except for single–flow reheat units) must be manually cleaned as they will not be flushed through. Since it is impossible to install a valve and basket screen (due to the inflexibility of the hose), a 1/4–in. (6.4 mm) horseshoe washer ahead of a thin sheetmetal blank will be installed in the No. 1 bearing and thrust bearing feed lines. This will allow the flushing oil to drain into the front standard. Install the washers and blanks at the discharge end of the hoses and let them lie in bottom of standard. Do not twist or kink these hoses. Install blank flanges at connections to thrust housing to exclude dirt. Some of the No. 2 and No. 3 turbine journal bearings have the oil feed hole in the bearing saddle tapped for pipe threads at the factory. By rolling the lower halves of these bearings out of the way, temporary pipe can be run from the tapped hole into the bearing pedestal or drain line. Should the feed hole not be tapped, the temporary piping can be fitted and locked into position. Extreme care must be taken not to score the rotor journal surface. The temporary pipe should be the same size as the hole in the

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Flushing Procedure for Turbine Lube Oil System

GEK 81515D

bearing saddle, preferably bushed up to the next larger size. A bronze gate valve in the temporary pipe is best for controlling flow. The oil should be discharged directly into the pedestal and never allowed to impinge on the lower–half bearing. Generator bearings will not be flushed through. The oil feed line should be disconnected at the end shield and jumpered via a gate valve to drain. To supplement the oil tank’s fine mesh screens the making of 100 mesh basket strainers, to be placed at the bearing oil feed line temporary outlet is recommended. M. MISCELLANEOUS DEVICES The following items are shipped in a clean condition and will not be flushed through; permanent magnet generator, bearing pressure gauge, overspeed trip device, and oil trip line. The oil feed lines to these devices should be disconnected and blanked off. NOTE The above items refer to Mark II B units only. On Mark III units with newer control systems it is only necessary to blank off the bearing pressure gauge. N. SAFETY Safety precautions and equipment that might be necessary should be considered. Post “No Burning and Welding” signs in appropriate areas. Restrict traffic passageways where oil soaked areas may cause a hazard. Equipment “Tag–Out” procedure should be in effect. III. FLUSHING PROCEDURE A. OIL TANK FILLING The oil tank should be filled about to the normal operating level. When pumps are turned on, the oil level in the tank will decrease as the piping system fills up with oil. However, makeup oil need not be added to restore the level to normal unless the level drops to less than 12 in. (304.8 mm) above the suction for the highest oil pump. Keep in mind that more oil merely means more time spent in heating, cooling, filtering, emptying, and filling the oil. During the filling of the tank, the oil coming in should be strained. This is usually accomplished by using a portable centrifuge and/or the customer’s lube oil purification system. This is important as new oil cannot be considered clean oil as the storage containers are not always perfectly clean. The customer’s lube oil purification system should remain in service throughout the flush. The vapor extractor must be in operation while filling the oil tank. B. COARSE FLUSH Install blanks behind the two horseshoe washers at No. 1 bearing and the thrust bearing, so as to flush through this line. Close all other valves and blank off all other feed lines. Start lube oil pumps. Starting with the No. 2 bearing and working towards the back of the machine, each one of the following valves, V2, V3, V4, V5, V6, V7, should be fully opened, in turn, until either or both the following conditions occur:

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GEK 81515D

Flushing Procedure for Turbine Lube Oil System

1. the pumps have reached their maximum allowable current. 2. all temporary valves from V2 to V7 are opened. The system should be allowed to reach hot flush operating temperature (160 to 180° F) (71 to 82° C). As the oil increases to a maximum (180° F) (82° C), the power requirements of each pump should drop. Hence, it may be possible to open more of the temporary flushing valves if condition 1 was the flow limiting factor. Valves V8 and V9 should not be opened at this time. This step will accomplish a number of functions. The pump motors will be tested. The major portion of the system will be leak checked. Maximum flows will be obtained, allowing the oil to heat up faster and also increased flow will better clean the drain lines. At the end of this period, shut down the oil system to enable the suspended particles to settle to the bottom of the tank. Drain and clean the system including the pedestals, before refilling. Whenever filling the tank, pump the oil back into the reservoir via the customer’s purification system. C. SEQUENTIAL FLUSH Sequential flushing is the most effective way of insuring maximum flow in the bearing feed lines. This method of flushing is dependent on a method of shutting off flow to the individual bearings. Then by selectively shutting off flow to two different groups of bearings, specific sections of oil pipe receive the maximum flow available. For example, the first stretch of pipe out of the oil tank will receive maximum flow if all bearings downstream of this line are being flushed. To achieve maximum flow in the branch line to the No. 2 bearing, it should be the only one being flushed. Sequential flushing is most advantageous when the order of valving arrangements is selected to “push” the dirt down the feed header, then down the branch lines and finally through the drain line to the oil tank. The following is the suggested approach to accomplish the above: 1. Flush all bearings and miscellaneous devices as outlined in the course flush procedure with one exception: Valves V6 and V7 should be closed to prevent flow in the hydrogen seal oil feed lines. This arrangement maximizes the flow in the initial section of the bearing feed header. 2. Blank off all miscellaneous devices in the front standard. Install blanks B1 and B2 ahead of the horseshoe washers. Install blank 3 (not shown on drawing) ahead of the steam seal regulator, if unit is equipped with hydraulic type. This arrangement provides maximum flow in the bearing feed header between the branch to the front standard and the branch to the midstandard. 3. Close valve V2. This arrangement provides maximum flow in the bearing feed header between the branch to the midstandard and the last turbine bearing. 4. Close valves V3 and V4. Install blank B4. This arrangement provides maximum flow in the bearing feed header just ahead of the last generator bearing. 5. Remove the blanks in the lines to the miscellaneous devices in the front standard. Move blanks B1 and B2 behind the horseshoe washers. Close valve V5. This arrangement provides maximum flow in the branch line to the front standard. 6. Move blanks B1 and B2 ahead of the horseshoe washers. Reinstall the blanks in the lines to the miscellaneous devices in the front standard. Open valve V2. This arrangement provides maximum flow in the branch line to the midstandard. 7. Close valve V2. Open valves V4, V5, V6, and V7. This arrangement provides maximum flow in the drain lines from the generator bearings.

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Flushing Procedure for Turbine Lube Oil System

GEK 81515D

8. Open V3. This arrangement provides maximum flow in the drain header between the midstandard and the last generator bearing. 9. Open V2 and remove blank B3. This arrangement provides maximum flow in the drain header between the front standard and the midstandard. 10. Remove the blanks in the lines to the miscellaneous devices in the front standard. Move blanks B1 and B2 behind the horseshoe washers. This arrangement provides maximum flow of drain oil returning to the tank. Based on the principles of sequential flushing, the mechanics of the previous steps are apparent. Steps 1 through 4 move the contaminants through the bearing header, section by section down its entire length. Steps 5 and 6 move the contaminants through the major branch lines. The last four steps progressively move the dirt through the drain line to the oil tank. Of course, this procedure will require modification based on the number and location of bearings and their oil lines. When flushing only one or two bearings, it may be determined that the supplemental pump is not being used to its best advantage. If the maximum flow can be maintained in the desired section, additional bearings may be flushed through to obtain maximum utilization of the supplemental pump. The length of time during each step should be about 3 hours. This length of time can be varied according to flush schedule, oil cleanliness, etc. D. SYSTEM CLEAN OUT As often as necessary, but at least once during the flush, all the oil should be drained from the turbine lube oil tank and processed through the customer’s lube oil purification system to a clean lube oil storage tank. Drain the oil from the entire system into barrels, including the loop seal, bearing drain enlargement, seal oil unit, and low points of main oil tank piping by means of cleanout plugs, and process this oil similarly. The main turbine oil tank, bearing standards, bearing drain enlargement, and loop seal should be mechanically cleaned. The system should be cleaned with lint–free rags, sponges, and squeegees only. When all possible dirt and contamination is removed from the system, the oil should be pumped back into the reservoir via the customer’s purification system. E. SECURING THE FLUSH Shut down the system. Repeat the System Clean Out procedure, but before refilling the oil tank, restore the piping to its normal configuration. When removing all temporary piping, exercise extreme care that dirt, paint chips, tools, etc., will not fall into pedestals. Replace the bearing pressure reduction valve in the oil tank. Renew the filters and install the float traps in the seal oil unit. Be sure all pre–assembled components that were not flushed through are clean. The oil should be pumped back into the reservoir via the customer’s purification system and an oil sample taken.

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GEK 81515D

Flushing Procedure for Turbine Lube Oil System

Fine mesh cone type screens may be installed in the bearing oil feed lines for turning gear operation. They will require constant monitoring for cleanliness and flow. It is imperative that they be removed before initial operation on steam. F. TERMINATION The flush will be terminated upon the recommendation of the General Electric Company Field Representative and the acceptance of the system by the customer and his agents. G. ACCEPTANCE CRITERIA The amount of suspended dirt or the “Contamination Level” can be measured by a particle count on a sample. A procedure for taking particle counts is outlined in Society of Automotive Engineers, Inc. AEROSPACE RECOMMENDED PRACTICE Publication No. ARP–598A. However, it should only be used as a general guide since the particle sizes listed differ from those tabulated below. If qualified laboratory service is available in the power station or conveniently nearby, it is recommended to take samples in carefully cleaned bottles and have particle counts made at the laboratory. H. ALLOWABLE CONTAMINATION LEVEL Samples taken from many turbines, some with the oil in service as long as 15 years, and at many points of the lubrication system have shown that the following recommendations hold for the lubricating oil.

MAXIMUM OPERATING OIL CONTAMINATION LEVELS Size Range

Max. Allowable Number of Particles Per 100 ml of Oil

Micrometers (µm) 1µm=0.001 millimeters 1µm=0.00004 inches

ACCEPTABLE (Except for Lift–Pump Operation)

5–10µm 10–25µm 25–50µm 50–100µm 100–250µm greater than 250µm

128,000 42,000 6,500 1,000 92 None

GOOD (Operation w/Lift–Pumps) 32,000 10,700 1,510 225 21 None

NOTE If a great portion of particles in the 50–250 micron bracket appear to be of a particular substance – such as metallic, black oxide, fly ash, asbestos – the source of this should be found and the content of this type of particles should be reduced. J. STRAINER BASKET SAMPLES The 100 mesh strainer baskets located at the end of each oil feed line should be sampled every 3 hours. To consider the individual oil line clean enough for operation, the total weight of a sample, after 3 hours of running, should be no greater than 0.1 gram. The largest particle should be no greater than 0.010 in. (0.3 mm). Individual samples should be evaluated and recorded on a data sheet.

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GE Power Systems General Electric Company One River Road, Schenectady, NY 12345 518 • 385 • 2211 TX: 145354