Defects in the support points of the pneumatic hoist during operation, such as cracks, deformation, and wear of the hook, need to be resolved through strict selection, standardized operation, regular testing, and professional maintenance. The specific plan is as follows:

1、 Types and Causes Analysis of Support Point Defects

Hook crack

Causes: material defects, overloading, long-term fatigue stress.

Consequence: Crack propagation may cause the hook to break, leading to heavy object falling accidents.

Hook deformation

Causes: Overloading, high temperature environmental thermal radiation, and long-term overload leading to plastic deformation.

Consequence: The expansion or twisting deformation of the hook opening can easily cause the suspended object to fall off.

Hook wear and tear

Cause: Friction occurs when the rope comes into direct contact with the hook body, resulting in lower material strength and hardness.

Consequence: When the wear of the cross-sectional height exceeds 10% of the original height, the strength weakens and it is prone to fracture.

2、 Targeted solutions

1. Selection and usage specifications for hooks

Selection principle:

Select the hook size, opening method, and tonnage based on the actual lifting weight and usage scenario to avoid overloading.

Priority should be given to manufacturers that have been established for a long time and have many partners to ensure product quality.

Operating standards:

Overloading lifting is strictly prohibited, and the hook should be kept stably connected to the object during the lifting process.

Avoid keeping the hook in a high-temperature environment for a long time (such as in metallurgical sites). If the thermal radiation temperature exceeds 300 ℃, isolation measures should be taken (such as welding a hook isolation plate).

2. Regular testing and maintenance

Testing content:

Appearance inspection: Use a 50x magnifying glass or non-destructive testing method to inspect the surface and interior of the hook for defects such as cracks, folds, and overburning.

Dimensional measurement: Use a steel ruler and vernier caliper to measure the wear of the cross-sectional height of the hook body hanging rope part. If it exceeds 10% of the original height, it needs to be replaced.

Deformation inspection: Check whether the increment of hook opening size (AM) is less than 15% of the original opening size (M), and whether the torsional deformation is less than 10 °.

Maintenance measures:

Regularly annealing the hook to eliminate internal stress.

The locking nut at the tail of the hook should have a reliable anti loosening device, and the thrust bearing should have a dust-proof device to prevent loosening of the fastening body and wear of the supporting steps.

3. Defect handling and scrapping standards

Crack treatment:

If cracks are found, immediately scrap the hook according to GB10051-88 standard, and welding repair is strictly prohibited (welding will change the material properties and lead to a decrease in bearing capacity).

Wear and tear treatment:

When the wear amount does not exceed 10% of the dangerous section, the load can be reduced for use; When it exceeds 10%, it must be replaced.

Deformation treatment:

When the opening or twisting deformation of the hook exceeds the standard, replace the hook immediately.

4. Optimization of support point auxiliary device

Safety device:

Pneumatic hoists used for heavy lifting must be equipped with safety devices to prevent accidental detachment of the lifted object (such as anti detachment barriers).

Lubrication management:

Regularly apply anti rust lubricating grease to moving parts such as hook bearings and pin shafts to reduce wear and corrosion.

3、 Preventive measures and long-term management

Training and Qualification:

Operators need to receive professional training, be familiar with safety operating procedures, and have the ability to inspect and maintain hooks.

Environmental control:

Maintain a dry and ventilated work environment with humidity below 60% to reduce corrosion of metal components by humid air.

Recording and tracing:

Establish a hook usage file to record selection, testing, maintenance, and replacement information for easy traceability and management.

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment