The number of broken wires, amount of corrosion (wear), deformation, length of use and fixed state of the wire rope should comply with national standards.
(1) The selection of steel wire ropes should meet the requirements, and the connection method should be correct.
a. There should be ≥2 fixed pressure plates at the end of the wire rope or be fixed on the drum and other components with wedges.
b. When the hook and other retrieval devices are in the lowest position (including the pit), the number of turns of the wire rope on the drum must be ≥ 2 turns in addition to the number of turns to fix the rope tail.
(2) The wire rope should be scrapped if any of the following conditions occurs:
a. For intertwined steel wire ropes, the number of broken wires within one lay length (referring to the axial distance of any one wire rope strand around a circle) reaches 10% of the total number of wires in the rope.
b. For steel wire ropes used to lift hot metal or dangerous goods, the number of scrapped broken wires shall be half of that of ordinary cranes. If the broken wires are concentrated in one part, or the broken wires are concentrated in one strand within six times the diameter of the wire rope, the number of broken wires should be It will be scrapped according to half of the provisions of a.
c. The corrosion or wear of the steel wire on the surface of the wire rope reaches 40% of the original wire diameter on the surface.
d. The diameter of the wire rope is reduced by 7%.
e. The wire rope has obvious internal corrosion.
f. If there is wear or corrosion on the surface of the steel wire rope, and there are a certain number of broken wires, the number of broken wires should be determined based on the provisions of a and b multiplied by the reduction coefficient: when the wear or corrosion rate is 10%, 15%, and 20% respectively , 25%, 30%-40%, the reduction coefficients are 85%, 75%, 70%, 60%, 50%.
g. The entire strand is broken or burned.
h. Part of the outer steel wire rope stretches into a "cage" shape or the diameter of the fiber core of the steel wire rope increases significantly.
i. The wire rope has serious deformations such as kinks, dead ends, hard bends, plastic deformation, and hemp core protrusion.
CN
