How to choose hoisting wire rope

Purpose, structure and type of wire rope

The type, structure, raw materials and production process of steel wire rope depend on the purpose. Carbon steel wire with circular section with diameter of 0.1 ~ 6.0mm is generally used for steel wire rope. When twisting sealed and semi sealed steel wire ropes, Z-shaped and other special-shaped steel wires shall be used. The types of steel wire ropes are divided according to their uses: suspension bridge ropes and mining steel wire ropes, bearing ropes for overhead cableways, traction ropes for transmission devices, elevator ropes, tying ropes for binding and towing goods, etc. The variety of steel wire rope is increasing and the structure is becoming more and more complex. In addition to various coated steel wires, stainless steel wires and bimetallic steel wires are also used. In order to ensure the safety and reliability of the steel wire rope, it is required that the steel wire rope has sufficient strength, good flexibility, twisting compactness, compression resistance, wear resistance, corrosion resistance and fatigue strength, among which the strength is the most important.

What requirements should be met when selecting crane wire rope?

The selection of steel wire rope shall meet the following requirements:

① Generally, the cross wound steel wire rope is selected so that it will not be twisted and loose when lifting goods, and there must be a quality certificate.

② The steel wire rope for hoisting hot or molten metal shall be asbestos core high temperature resistant steel wire rope.

③ The hoisting and luffing mechanism shall not use braided and extended steel wire rope. When it is necessary to lengthen the steel wire rope, ensure that the joint connection strength is not less than 90% of the breaking force of the steel wire rope, and do not enter the drum through the pulley.

Under what circumstances should the crane wire rope be scrapped?

When the steel wire rope meets one of the following conditions, it shall be scrapped:

① The number of broken wires of steel wire rope in one lay pitch exceeds 10% of the total number of wires.

② The wear amount of the outer steel wire exceeds 40% of the original diameter. When it is insufficient, it can be scrapped according to the number of broken wires after removal.

③ The number of broken wires of steel wire rope for hoisting hot metal or dangerous goods reaches half of the number of scrapped broken wires of steel wire rope of general hoisting equipment, including the reduction of steel wire surface corrosion.

④ The diameter of steel wire rope is reduced by 7%.

⑤ The whole strand of steel wire rope is broken or the hemp core is exposed, the local outer steel wire extends in a cage state, and the knot is killed.

Key points for replacement of Hoisting Machinery wire rope

When replacing a new steel wire rope, the original design model, diameter, nominal tensile strength and qualified steel wire rope must be used. If only the diameter is the same and other requirements are lower than the requirements, the service life of the steel wire rope will be affected.

It is forbidden to use the steel wire rope without qualification certificate. If the diameter of the steel wire rope is inconsistent with the original design, it must first ensure that there is the same total breaking force as the original design, and the upper and lower difference of the diameter shall not be greater than: the diameter less than 20mm is 1mm; 1.5mm for diameter greater than 20mm. Too thick will cause the steel wire rope to rub each other when winding on the drum and enhance the wear.

When replacing or winding the steel wire rope, pay attention not to knot the steel wire rope. Practice has proved that the knotted steel wire rope is most likely to be worn and broken in use. It is forbidden to connect two steel wire ropes in the lifting mechanism.