How do you Inspect a Lifting Chain?

Lifting chain is an indispensable and important lifting device for cranes. The length of chain can be adjusted according to the lifting height of lifting objects. It plays an important role in improving the efficiency of cranes and expanding the operation scope of cranes.

Appearance inspection of lifting chain:

1. Whether the inner/outer chain piece is deformed, cracked or corroded .

2. Whether the pin is deformed, rotated or corroded.

3. Whether the roller is cracked, damaged or excessively worn.

4. Whether the joint is loose and deformed.

5. Whether there is abnormal sound or abnormal vibration during operation,whether the lubrication condition of lifting chain is good.

6. Whether the chain hoist tag, ultimate working load identification is clear.

Lifting chain inspection methods:

（1）Routine Lifting chain inspection: The operator or designated person shall check the appearance of the lifting chain every working day, and record whether the lifting chain can be used normally.

（2）Chain distortion: The lifting chain is twisted, bent, elongated and cannot be used when the standard is exceeded.

（3）Hook deformation: The hook mouth is deformed or distorted beyond the standard can not be used.

（4）Cracks: The parts with cracks observed by naked eyes or detected should not be used.

Scrapping standard:

1. Link:

（1）Deformation: The external length of the lifting chain increased > 3%. The internal length of the lifting chain increased > 5%.

（2）Wear: The cross section diameter should not be reduced by more than 10% after the lifting chain diameter is worn.

（3）Crack: No cracks are allowed on the surface of the link.

（4）Bending or distortion: No apparent bending or distortion of the link is permitted. No serious corrosion or adhesion that cannot be removed is allowed.

2. The hook:

(1) Opening degree of the hook: The increase of the size of the hook opening degree shall not exceed 10% of the nominal value.

(2) Bearing section wear: The section thickness at the wear point shall not be reduced by more than 5%.

(3) Distortion: The distortion of the hook is not more than 5%.

(4) Crack: The whole hook surface is not allowed to have cracks found by naked eyes or equipment inspection.

(5) Nick and gouge: It can be repaired by grinding or filing, there should be a smooth transition between the compound surface and the adjacent surface without section protruding. The section thickness of the grinding shall not exceed 5%.

3. The suspension loop:

(1) Distortion: The distortion of the whole suspension loop shall not exceed 5%.

(2) Wear: The surface wear of the suspension loop shall not exceed 10% of the original diameter.

(3) Cracks: No cracks are allowed on the entire suspension loop surface.

4. Shackles and other accessories:

(1) Opening degree: The size of opening degree of shackle shall not exceed 10% of the original nominal value.

(2) Wear: The wear of the bolt or pin shaft diameter shall not exceed 10% of the original diameter; Wear on the stressed section shall not exceed 5%.

(3) Crack: The whole accessory surface is not allowed to have cracks found by naked eyes or equipment inspection.