Inspection Of Wire Rope Procedure

INSPECTION OF WIRE ROPE SLINGS PROCEDURE

Rev: Page 1 of 4

PT. BHAITA Authorized by: Director

Issued by: HSE Dept.

Date of issue: Aug, 2009

INSPECTION OF WIRE ROPE SLINGS Guidelines Store slings in a manner that will protect them from damage by moisture, heat, corrosion or physical abuse. Determine that the sling is being used in accordance with the rated capacity as listed in the current catalog of the sling manufacturer. Apply the following criteria for rejection when examining a sling. Broken wire criteria For strand laid and single part slings - ten randomly distributed broken wires in one rope lay or five broken wires in one strand in one rope lay. (The length of lay in a wire rope is the length of travel which any strand makes in one full revolution about the wire rope core.). Abrasion, scrubbing or peening causing loss of more than 1/3 the original diameter of outside individual wires. Evidence of rope deterioration from corrosion. Kinking, crushing or other damage that results in detrimental distortion of the rope structure. Any marked reduction in diameter either along the entire main length or in one section. Unlaying or opening up of a tucked splice. Core protrusion along the main length. End attachments that are cracked, deformed, worn or loosened. Any indication of strand or wire slippage in end attachments.

AR/HR/procedure

INSPECTION OF WIRE ROPE SLINGS PROCEDURE

Rev: Page 2 of 4

PT. BHAITA Authorized by: Director

Issued by: HSE Dept.

Date of issue: Aug, 2009

SLINGLINE MAINTENANCE Due to the importance of the slingline during mast raising and lowering, BHAITA considers it imperative to perform proper slingline maintenance before and after each use. While it might be possible to develop a formula that would indicate the service life for a sling-line, variations in operational and environmental conditions could reduce the effectiveness of the formula. For these reasons BHAITA considers a thorough visual inspection and, if necessary, a certified test pull to be the safest and most accurate method of determining the service life of a slingline.

The following information is provided to assist operational personnel in performing proper slingline maintenance. SLINGLINE INSPECTION As indicated above, the best way to determine whether a slingline has outlived its usefulness is by means of a visual inspection. Although some personnel might consider such an inspection an imposition on their time, the benefits of the inspection heavily offset the time required. During the inspection, consideration should be given to three principle factors that can affect the life of a slingline. These are wear due to operation, corrosion and incidental damage. When conducting the inspection, the following points may be used as general guidelines in determining the type and extent of wear on the slingline. a)

Wear Due to Operation This can be defined as that wear which occurs through the normal use of the slingline. This type of wear is primarily evident in the areas near the slingline sockets and those sections of the slingline which bend and travel over sheaves. Emphasis should be placed on locating broken wires, elongation and reduction in area of the wire rope. Although Appendix A of API Spec. 4E states that "a line with any broken wires should be replaced", some wire rope manufacturers consider this too strict and make allowance for two broken wires before retiring the slingline from service. The inspection of the slingline for broken wires must be very thorough, since much of the time the breaks occur on the inner wires that form the strands. Wire rope manufacturers suggest the best time to inspect for broken wires is after the mast has been raised or lowered and the load on the wires is relaxed. Elongation of the wire rope in a slingline is a good indicator of how

AR/HR/procedure

INSPECTION OF WIRE ROPE SLINGS PROCEDURE

Rev: Page 3 of 4

PT. BHAITA Authorized by: Director

Issued by: HSE Dept.

Date of issue: Aug, 2009

much it has been worked. While wire rope is designed to have a certain amount of elasticity, an overworked wire rope or slingline will tend to stretch without returning to its normal lay length. The length of lay in a wire rope is the length of travel which any strand makes in one full revolution about the wire rope core. When a significant increase in the length of the lay is evident in any section of the slingline, it should be replaced. The API specifications for wire rope used in slinglines (6 x 19 classification, 6 x 37 classification) states that the length of lay should not exceed 7-1/4 times the nominal diameter of the rope. Again, however, it may be advisable to consult the wire rope manufacturer regarding specific measurements. When inspecting slinglines for elongation the critical areas are those sections for the rope which pass over sheaves. Reduction in area due to abrasion is another indicator of how much a slingline has been worked. Again the critical areas are those sections of the slingline which bend and pass over sheaves. Included in this category is reduction in rope diameter due to core failure. Any slingline that shows a reduction in rope diameter should be replaced. The diameter of the rope can easily be measured at several locations along the line with a pair of calipers, and these measurements can be compared to those taken when the rope was new. b)

Wear Due to Corrosion This type of wear is primarily evident in the slinglines that have not been maintained through proper slingline lubrication. The damage may be due to operational or environmental conditions; but once the rust or corrosion has penetrated the inner surfaces of the strands and wires, the slingline should be replaced. The reason here is that free movement required to develop the full strength of the rope is prohibited by the presence of the corrosion. The best way to guard against this type of wear is to periodically lubricate the wire rope. Check with the wire rope manufacturer regarding the appropriate type of lubricant for use in a specified territory.

c)

Wear Due to Incidental Damage

AR/HR/procedure

INSPECTION OF WIRE ROPE SLINGS PROCEDURE

Rev: Page 4 of 4

PT. BHAITA Authorized by: Director

Issued by: HSE Dept.

Date of issue: Aug, 2009

Incidental damage is due to incorrect handling of sling-lines. This may result in bends, kinks or birdcages in the wire rope is reason for slingline replacement. Slinglines should not be left hanging in the mast, but should be stored on reels or coils. Proper handling and storage of slinglines is similar to any other wire rope product and is discussed elsewhere in this manual.

CERTIFIED TEST PULL If a good visual inspection for the slingline reveals little in terms of damage due to operation, corrosion or incidental damage, a certified test pull may prove helpful in determining the safety of the slingline. Due to the variations in mast design, the nominal strength of the slinglines used will differ. Reference should be made to the revving diagrams for detailed information.

AR/HR/procedure