API 9A:2004 pdf download.Specification for Wire Rope.
NOTE 2 The requirements for breaking force take into account: (I) the rope size; (ii) whether or not ropes are produced in series, i.e. repeatedly produced; (iii) whether or not the minimum breaking force factor is consistent throughout a range of diameters; (iv) whether or not the manufacturer is operating a quality system in accordance with ISO 9001. certified by an accredited third party certification body.
4.5.3.2 Ropes produced In series — Manufacturer operating a quality system in accordance with ISO 9001, certified by an accredited third party certification body
The manufacturer shall be able to provide the results from type testing in accordance with the sampling and acceptance criteria given in Annex H.
Type testing shall be repeated on any rope that has its design changed in any way which results in a modified (e.g. increased) breaking force. If the same design, apart from wire tensile strength grades, is used for ropes of a lower grade or lower breaking force, or both, than the one which has successfully passed the type testing requirements. it shall not be necessary to repeat the tests on those ropes provided the breaking force is calculated with the same spinning loss.
Subsequent production lengths of ropes produced in series shall be deemed to conform to the breaking force requirements when the manufacturer has satisfactorily completed
a) the appropriate type tests (see Annex H), and
b) a periodic breaking force test in accordance with Method I or one of the alternative methods, known as Methods 2 and 3 (see 5.1.4.2 and 5.1.4.3).
on a sample from every twentieth production length.
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 caIculated 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.
5.1.4.3 Method 3 — Calculated measured (pre-spin) breaking force
Add together the measured breaking forces of all the individual wires before they are laid into the rope and multiply this value by the total spinning loss factor obtained from the results of type testing. The total spinning loss factor used in the calculation shall be the lowest of the three values obtained from type testing.
The wires shall be tested ri accordance with the wire tensile test specified in Iso 6892.
NOTE The result from this test is known as the calculated measured (pre-spin) breaking force.
API 9A:2004 pdf download
