Standard for decommissioning, maintenance and replacement of wire rope slings
In addition to the wear of the outer layer steel wire, the wholesale corner protector is mainly broken due to metal fatigue caused by repeated bending when bypassing the hook and the suspended object. Therefore, the ratio of the hook or the suspended object to the diameter of the wire rope determines the service life of the wire rope rigging. Key factor.
When one of the following situations occurs, the use of wire rope slings should be stopped or repaired, replaced or scrapped.
1. Irregular distribution of damage: within the length of 6 times the diameter of the wire rope, the total number of broken wires can be seen to exceed 5% of the total number of wire ropes;
2. The wire rope is partially damaged by broken wires: there are more than three broken wires gathered together;
3. There is a collection of broken wires on the surface of the cable eye, or the broken wires are concentrated in the metal sleeve, near the splicing point, and in the splicing connection strands;
4. The wire rope is seriously worn: the diameter of the wire rope measured at any position is less than 90% of the original nominal diameter;
5. The steel wire rope is seriously corroded: the flexibility is reduced, the surface is obviously rough, the diameter of the steel wire rope is measured at the rusted part, and the size has not reached 93% of the original nominal diameter;
5. The wire rope is distorted, crushed, damaged or the wire rope is flattened more than 20% of the original nominal diameter due to knotting, twisting and extrusion;
6. Thermal damage to the wire rope: the wire rope is smelted due to the electric arc, the molten metal is scalded, or the strength decreases due to prolonged exposure and high temperature environment;
7. The plug joint is severely squeezed, worn, or damaged by the metal sleeve (such as cracks, severe deformation, corrosion), or the diameter is reduced to 95% of the original nominal diameter;
8. ratchet strap manufacturers The metal sleeve or the plug-in part of the fixed connection at the rope end slides out.