Wire rope use and obsolescence standards

1. Matters needing attention in the use of wire rope

(1) Check the content before use

The degree of wear, corrosion, stretching, bending, deformation, fatigue, broken wire, and exposure of the core of the wire rope.

(2) Maintenance precautions

1. The service life of the wire rope has a lot to do with the method of use. Therefore, it should be used according to the regulations, dragging and throwing are prohibited, overloading is not allowed during use, the wire rope is not allowed to bend at an acute angle, and the lifting speed is not allowed to change sharply. Avoid shock loads.

2. When the wire rope has rust and dust, use a wire brush to remove it and apply oil.

3. The steel wire rope should be oiled every 4 months. It is best to soak the rope core with hot oil (about 50℃) and wipe off the excess grease.

4. After the wire rope is wound, it should be placed in a clean and dry place, and should not be stacked to prevent sprain.

5. The end of the wire rope should be fastened with steel wire or welded with alloy with low melting point, or can be fastened with iron hoops to avoid loosening of the rope head.

6. ​​During use, if oil droplets are squeezed out on the surface of the wire rope, it means that the wire rope has been subjected to considerable strength. At this time, the load should be stopped and the inspection should be carried out. If necessary, replace with a new wire rope.

7. During use, care should be taken to prevent the following situations from appearing:

(1) The wire rope is in contact with the welding wire.

(2) Direct contact between steel wire ropes.

(3) Steel wire rope and metal sharp edges and corners are often rubbed.

(4) The wire rope is passed through the broken pulley.

(5) The hoisting angle exceeds 60º.

(6) The steel wire rope used on high temperature objects must be insulated to prevent the strength and lifespan from being reduced.

(7) When the wire rope is scrapped and cut, there should be measures to prevent the strands from spreading.

2. Steel wire rope scrap standard

The wire rope should be scrapped if one of the following occurs:

1. The number of broken wires in a lay length (referring to the axial distance of any wire rope strand around a circle) for the entangled wire rope reaches 10% of the total wire number of the rope.

2. For steel wire ropes that are used for lifting hot metal or dangerous goods, the number of scrapped and broken wires is half of that of ordinary cranes. If wire breakage occurs locally, or within six times the diameter of the wire rope, it should be Half of the stipulated in item 1 can be scrapped.

3. The corrosion or abrasion of the steel wire on the surface of the wire rope reaches 40% of the original wire diameter.

4. The steel wire rope has obvious internal corrosion.

5. The wire rope diameter is reduced by 7%.

6. ​​There are cracks or slipping deformation at the joint between the steel wire rope and the aluminum alloy; the insertion part of the inserted braided steel wire rope is severely pulled off; the cast wire rope anchorage and the wire rope have displacement at the connection point, and the phenomenon of pulling off occurs.

7. The surface of the steel wire rope is worn or corroded, and there are a certain number of broken wires. The number of broken wires should be determined by multiplying the provisions of item 1 or item 2 by the reduction factor: when the wear or corrosion rate is 10%, 15 %, 20%, 30%-40%, the reduction factor corresponds to 85%, 75%, 70%, 60%, 50%.

8. The whole strand is broken or burned out.

9. The local outer steel wire rope elongates in a "cage" shape or the diameter of the steel wire rope fiber core increases severely.

10. The wire rope is seriously deformed such as kinks, dead ends, hard bends, plastic deformation, and hemp core out.