The maintenance and repair of port crane hooks

1.Regularly check the wear of the hook and measure its wear degree and opening size        

No cracks can appear on the dangerous section. When the wear amount of the dangerous section is greater than 10% or after being reconfirmed by the relevant technical department, it should be scrapped to achieve the purpose of reducing the load. When the hook opening size is enlarged to 15% or equal to the original size or the same inner diameter, the hook head should be scrapped.        

2.Regularly check the deformation of the hook body and hook column and the condition of the tail thread        

When the deformation and twisting deflection angle of the hook body and hook column are greater than 10°, the hook should be scrapped; when checking, the nut should be removed and cleaned of dirt, and when there are cracks or fatigue deformation on the thread or the tail empty knife slot, the hook head should be scrapped.        

3.Regularly check whether the bolts of the hook yoke and its parts are tightened        

The hook yoke cannot have cracks and deformation, and the screws of each part cannot be loose. When these conditions occur, the cut and dropped bolts should be replenished immediately.        

4.Lubricate all movable joints        

Lubricate according to requirements.        

5.State detection        

When conducting load tests, the test load should be 1.25 times the rated load as the standard, and the hanging time should not be less than 10 minutes. After loading the test load, the hook opening deformation should not exceed 0.25%, and no permanent deformation or cracks should occur after unloading.

In order to ensure safety, the hook should be inspected, and when one of the following situations is found, it should be scrapped immediately.

①Cracks appear.

②The wear amount of the dangerous section is not greater than 5% of the original height; the hook manufactured according to the standard along the line should be greater than 10% of the original size.

③The opening degree increases by 15% than the original.

④The torsional deformation exceeds 10 degrees.

⑤Plastic deformation occurs on the dangerous section or the hook neck.

⑥When the wear amount of the hook lining sleeve reaches 50% of the original size, the core sleeve should be scrapped. ⑦When the wear amount of the hook core shaft reaches 5% of the original size, the core shaft should be scrapped. There is also one point to note, the above defects of the hook must not be welded.