API 9A:2004 pdf download.Specification for Wire Rope
1 Scope
This International Standard specifies the minimum requirements and terms of acceptance for the manufacture and testing of steel wire ropes not exceeding rope grade 2160 for the petroleum and natural gas industries. Typical applications include tubing lines, rod hanger lines, sand lines, cable-tool drilling and clean out lines, cable tool casing lines, rotary drilling lines, winch lines, horse head pumping unit lines, torpedo lines, mast-raising lines, guideline tensioner lines, riser tensioner lines, mooring and anchor lines. Ropes for lifting slings and cranes, and wire for well-measuring and strand for well-servicing, are also included. The minimum breaking forces for the more common sizes, grades and constructions of stranded rope are given in tables. However, this International Standard does not restrict itself to the classes covered by those tables. Other types, such as ropes with compacted strands and compacted (swaged) ropes, may also conform with its requirements. The minimum breaking force values for these ropes are provided by the manufacturer. For information only, other tables present the minimum breaking forces for large diameter stranded and spiral ropes (i.e. spiral strand and locked coil), while approximate nominal length masses for the more common stranded rope constructions and large diameter stranded and spiral ropes are also given.
5.1.4.2 Method 2 — Calculated measured (post-spin) breaking force
Add together the measured breaking forces of all individual wires after they have been removed from the rope and multiply this value by either a) the spinning loss factor derived from Annex F, or b) the partial spinning loss factor obtained from the results of type testing. The partial spinning loss factor used in the calculation shall be the lowest of the three values obtained from type testing. In the case of triangular strand ropes, the triangular centre of the strand may be considered as an individual wire. Test the wires in accordance with the wire tensile test specified in Clause B.2 or in ISO 6892. NOTE The result from this test is known as the “calculated measured (post-spin) breaking force”. When this method (i.e. Method 2) is used for the periodic test (see Table 4) and the calculated measured (post-spin) breaking force value is less than the intended minimum breaking force value, carry out another test using Method 1. If the measured (actual) breaking force in this second test fails to meet the intended minimum breaking force value, de-rate the minimum breaking force to a value not exceeding the measured (actual) breaking force value and repeat the type testing using Method 1. In such cases, either de-rate the rope grade in line with the de-rated minimum breaking force value or delete it from the rope designation.