How to prevent the chain hoist from being overloaded?

How to prevent the chain hoist from being overloaded?

1. Inspection before use

1.1 Check the integrity of the equipment
Before using the chain hoist, it must be thoroughly inspected to ensure that all parts of the equipment are intact and undamaged. The inspection includes whether the chain has cracks, deformation or wear, whether the hook has cracks, deformation or sharp angles, and whether the brake is working properly. According to relevant safety regulations, the cross-sectional wear of the hook should not exceed 10% of the nominal size, and the chain ring diameter wear should not exceed 10% of the nominal size, otherwise it should be stopped from use and repaired or replaced. In addition, it is necessary to check whether the shell of the chain hoist has bumps or damage to ensure that its appearance is intact to avoid accidents during use.

1.2 Confirm the rated load
Clarifying the rated load of the chain hoist is a key step to prevent overloading. The rated load of the chain hoist is usually indicated on the nameplate of the equipment, and the operator must carefully check whether the weight of the hoisted object is within the rated load range of the chain hoist. For example, if the weight of the hoisted object is 1.5 tons, a chain hoist with a rated load of 2 tons should be selected to ensure sufficient safety margin. According to industry standards, the rated load range of chain hoists is generally 0.5~20 tons, and operators should choose equipment of appropriate tonnage according to actual needs. At the same time, a trial hoist should be carried out before use. The heavy object should be lifted from the ground at a certain height and kept for a period of time to observe whether the equipment is abnormal, such as whether the chain is smooth and whether the brake is reliable, etc., to ensure that the equipment can work normally under the rated load.

2. Choose the right equipment

2.1 Select according to the weight of the heavy object
Choosing the right chain hoist model is the key to preventing overloading. The rated load range of chain hoists is generally 0.5~20 tons, and different models of chain hoists are suitable for lifting heavy objects of different weights. For example, for heavy objects weighing about 1 ton, a chain hoist with a rated load of 2 tons should be selected to ensure sufficient safety margin. According to relevant industry data, when using a chain hoist with a rated load of 2 tons, its actual maximum load capacity can reach about 2.2 tons, but to ensure safety, it should be strictly controlled within the rated load range. In addition, for heavier goods, such as heavy objects over 5 tons, a chain hoist of the corresponding tonnage should be selected and ensure that it meets safety standards.

2.2 Consider the safety factor
When choosing a chain hoist, in addition to considering the weight of the object being hoisted, the safety factor also needs to be considered. The safety factor refers to the ratio of the maximum load allowed by the equipment to the rated load, which is usually 1.5~2 times. For example, for a chain hoist with a rated load of 2 tons, the maximum load allowed should be 3~4 tons. However, in actual use, the rated load should be strictly observed and overloaded. The safety factor is set to ensure that the equipment can still operate safely when the equipment is slightly worn or an accident occurs during operation. According to relevant safety regulations, the safety factor of the chain hoist shall not be less than 1.5. Operators should fully consider this factor when selecting equipment to ensure the safety of the equipment during use.

3. Operation process control

3.1 Pull evenly
During the operation of the hand chain hoist, pulling the hand chain evenly is an important part of preventing overload. The chain design of the hand chain hoist is based on a certain tension range. If the force is too strong or uneven, the chain will be subjected to excessive tension at the moment, thereby increasing the risk of overload. According to relevant experimental data, when the force of pulling the chain exceeds 20% of the rated tension, the wear rate of the chain will accelerate by 30%, and the chain may be deformed or broken. Therefore, when pulling the chain, the operator should maintain a steady and even force to avoid sudden jerk or emergency stop. In addition, the direction of the hand chain should be in the same plane as the hand chain wheel to ensure the smooth operation of the chain and reduce the additional tension caused by chain distortion or jamming.

3.2 Monitoring abnormal conditions
During the operation of the hand chain hoist, real-time monitoring of abnormal conditions of the equipment is the key to preventing overload. The operator should pay close attention to the operation status of the hand chain hoist. Once an abnormality is found, the operation should be stopped immediately and checked. For example, if you feel unusually hard when pulling the chain, it may be a sign of chain jam or overload. According to industry statistics, about 80% of chain hoist failures are caused by improper operation or overload. Therefore, when the operator finds that the hand pull force is significantly greater than the normal pull force, he should stop pulling immediately and check whether the chain is jammed, whether the hook is hung firmly, whether the weight is balanced, etc. In addition, it is also very important to regularly check the braking performance of the chain hoist. Excessive wear of the friction plate of the brake will cause brake failure, thereby increasing the risk of overload. It is recommended to conduct a comprehensive inspection of the braking performance of the chain hoist every 100 uses or every quarter to ensure that it can brake reliably under the rated load.

4. Regular maintenance and inspection

4.1 Check the wear of key components
Regularly checking the wear of key components of the chain hoist is an important measure to prevent overload. The chain is one of the core components of the chain hoist, and its wear directly affects the safety of the equipment. According to relevant research, when the wear of the chain reaches 10% of its diameter, its load-bearing capacity will be reduced by about 20%. Therefore, it is recommended to conduct a detailed inspection of the chain of the hand chain hoist every 50 uses or every quarter, focusing on whether the chain has cracks, deformation, rust, etc. At the same time, the wear of the hook should not be ignored. When the opening of the hook increases by 15% or the torsion deformation of the hook body exceeds 10%, its load-bearing capacity will decrease significantly, which is very likely to cause overload risks. In addition, excessive wear of the brake friction pad will lead to brake failure and increase the possibility of overload. It is recommended to check the wear of the brake friction pad before each use. When the wear of the friction pad reaches 50% of its thickness, it should be replaced immediately.

4.2 Testing the braking and load limiting device
The braking and load limiting device of the hand chain hoist is a key safety facility to prevent overload. The reliability of the braking device is directly related to the safety of the equipment during operation. It is recommended to conduct a comprehensive test of the braking device of the hand chain hoist every 100 uses or every quarter to ensure that it can brake reliably under the rated load. During the test, you can lift the weight with the chain hoist and then suddenly stop pulling the chain to observe whether the brake can brake quickly and reliably to prevent the weight from sliding down. The load limiter is the last line of defense against overloading, and its accuracy is crucial. According to relevant industry standards, the load limiter of the chain hoist should automatically stop working at 110% of the rated load. It is recommended to calibrate and test the load limiter of the chain hoist every six months or every 200 uses to ensure that it can be accurately triggered at 110% of the rated load to prevent the equipment from overloading.

5. Personnel training and management

5.1 Professional training of operators
Professional training of operators is an important link in preventing the overloading of chain hoists. According to relevant industry surveys, about 60% of chain hoist accidents are caused by lack of professional training or improper operation of operators. Therefore, it is crucial to provide systematic professional training for operators.
Training content: The training should include the structural principle, operation process, safety precautions, common troubleshooting, etc. of the chain hoist. For example, operators should understand the basic knowledge of the rated load of the hand chain hoist, the inspection methods of the chain and hook, the working principle of the brake, etc. At the same time, through actual operation drills, operators should be proficient in the correct operating skills, such as pulling the chain evenly and avoiding oblique lifting.
Training methods: Training can be carried out in a variety of ways, such as theoretical lectures, on-site practical operations, and case analysis. Theoretical lectures can help operators systematically learn the relevant knowledge of hand chain hoists; on-site practical operations can allow operators to practice operating skills in a real environment; case analysis can analyze typical accident cases to make operators deeply aware of the hazards of illegal operations such as overloading.
Training effect evaluation: After the training, the training effect should be evaluated through assessment. The assessment content can include theoretical knowledge tests and actual operation assessments. Only operators who pass the assessment can obtain an operating qualification certificate and take up their posts with the certificate. In addition, operators should be retrained regularly to ensure that their operating skills and safety awareness are always maintained at a high level.

5.2 Establish an operating specification system
Establishing a sound operating specification system is an important guarantee to prevent the overloading of hand chain hoists. By formulating clear operating specifications and management systems, the behavior of operators can be standardized to ensure the safe use of hand chain hoists.
Operating specification formulation: The operating specifications should cover all aspects of the hand chain hoist, such as pre-use inspection, operation process control, and post-use maintenance. For example, in terms of pre-use inspection, it should be clearly stipulated that operators must check the integrity of key components such as chains, hooks, and brakes; in terms of operation process control, it should be stipulated that operators must pull the chain evenly to avoid oblique pulling and crooked hanging, and overloading is strictly prohibited; in terms of post-use maintenance, operators should be required to clean the equipment in time and apply lubricating oil to prevent the equipment from rusting.
System implementation and supervision: After the operating specification system is formulated, it must be strictly implemented and strengthened. The enterprise should set up a special safety supervision department or personnel to supervise and inspect the daily operating behavior of operators. Any violation of the operating specifications should be corrected in time and given corresponding penalties. At the same time, a reward mechanism should be established to commend and reward operators who comply with the operating specifications and have a strong sense of safety, so as to encourage operators to consciously comply with the operating specifications.
Continuous improvement: The operating specification system should be continuously improved according to actual conditions. With the development of hand chain hoist technology and the accumulation of operating experience, the operating specifications should be revised and improved in a timely manner. For example, when new safety hazards or operating problems are found, they should be incorporated into the operating specifications in a timely manner to ensure that the operating specifications are always scientific and practical.

6. Summary
In summary, preventing the overload of hand chain hoists requires multiple aspects, and ensuring the safe operation of the equipment through comprehensive preventive measures and strict management means.
Before use, it is crucial to fully check the integrity of the equipment, including key components such as chains, hooks, brakes, and any minor damage may bury safety hazards. At the same time, clarify the rated load of the hand chain hoist and select the appropriate tonnage equipment according to the weight of the hoisted object, which is the basis for preventing overload. For example, for a heavy object of about 1 ton, choosing a 2-ton hand chain hoist can provide sufficient safety margin. According to industry standards, the rated load range of the hand chain hoist is 0.5~20 tons, and the operator must strictly abide by this range.
During the operation, pulling the hand chain evenly is an important part of preventing overload. Experimental data show that when the force of pulling the chain exceeds 20% of the rated tension, the wear rate of the chain will accelerate by 30%, and may cause the chain to deform or break. Therefore, the operator should maintain a steady and uniform force to avoid sudden yanking or emergency stop. In addition, it is also very important to monitor the abnormal conditions of the equipment in real time. Once the hand-pulling force is found to be significantly greater than the normal pulling force, the operation should be stopped immediately and checked. Industry statistics show that about 80% of the failures of hand chain hoists are caused by improper operation or overloading.
Regular maintenance and inspection are the key to ensure the long-term safe operation of equipment. The wear of key components will reduce the load-bearing capacity of the equipment. For example, when the chain wear reaches 10% of its diameter, its load-bearing capacity will be reduced by about 20%. Therefore, it is recommended to conduct a detailed inspection of the chain hoist chain every 50 times of use or every quarter. At the same time, the reliability of the brake and load limiter is directly related to the safety of the equipment. It is recommended to conduct a comprehensive test of the brake device of the hand chain hoist every 100 times of use or every quarter, and calibrate and test the load limiter every six months or every 200 times of use.
Personnel training and management is another important link to prevent overloading. About 60% of chain hoist accidents are caused by lack of professional training or improper operation of operators. Therefore, it is very important to provide systematic professional training for operators, and the training content should cover the structural principle, operation process, safety precautions, etc. of the chain hoist. In addition, a sound operating specification system should be established to regulate the behavior of operators through clear operating specifications and strict supervision mechanisms to ensure the safe use of chain hoists.

In short, through the above measures, the overloading of chain hoists can be effectively prevented, the safe operation of equipment can be guaranteed, the occurrence of accidents can be reduced, and work efficiency can be improved.