Targeted preventive measures should be taken for pneumatic hoists in operation at different stages of use to ensure equipment safety and extend service life. From the three key periods of initial use, daily operation, and long-term idle, combined with technical specifications and practical cases, specific precautions are summarized as follows:

1、 Initial use phase: Key controls during the break in and debugging periods

1. Installation and commissioning specifications

Basic fixation: Ensure that the equipment is installed on a flat and solid ground, and the support legs need to be calibrated with a level after deployment to avoid structural deformation caused by foundation settlement.

Case: Due to the failure to calibrate the levelness of the support legs at a construction site, the equipment tilted during lifting and the main arm broke.

Air source connection: Use compressed air that meets the equipment requirements (usually with a pressure range of 6-8 bar), and the gas supply pipeline should be equipped with filters, pressure regulating valves, and oil mist devices to prevent impurities from entering the pneumatic system.

Technical basis: According to the ISO 8573-1 standard, compressed air must achieve a cleanliness level of 3 (solid particles ≤ 1 μ m, oil content ≤ 0.01mg/m ³).

Load testing: Before initial use, a three-level test of no-load, half load, and full load is required to check the sensitivity of the brake, the reliability of the limit switch, and the structural stability.

Operation points: During full load testing, observe whether the hook slides down after being stationary for 5 minutes. If the sliding amount exceeds 10mm, adjust the brake.

2. Operation restrictions during the break in period

Load control: During the first 200 hours of operation, the load should not exceed 80% of the rated value to avoid early wear of components such as gears and bearings due to excessive friction.

Data support: According to statistics from a certain enterprise, equipment that runs overloaded during the break in period has a 40% reduction in gear life.

Speed limit: Control the lifting speed within 70% of the rated value to reduce damage to the structure caused by impact loads.

Case: A logistics warehouse experienced pitting corrosion on the sprocket teeth due to high-speed operation during the break in period, resulting in an increase of 20000 yuan in maintenance costs.

Lubrication cycle: During the running in period, add lubricating grease every 50 hours and choose a model with lower viscosity (such as NLGI 0) to ensure sufficient lubrication of the friction surface.

2、 Daily operation phase: maintenance and operation optimization during high-frequency use

1. Pre operation inspection

Structural inspection: Before daily work, check whether there are cracks, deformations, and loose bolt connections in key parts such as the main arm, support legs, and hooks.

Tool application: Use a torque wrench to verify the torque value specified in the equipment manual (such as tightening M24 bolts to 500-600N · m).

Pneumatic system inspection: Observe whether the pressure gauge reading is stable, check whether the oil level of the oil mist device is sufficient (the oil cup level should be maintained at 1/2-2/3), and auscultate whether there is any abnormal air leakage sound in the valve body.

Case: A steel plant failed to replenish the lubricating oil of the oil mist device in a timely manner, resulting in aging of the cylinder seal ring and severe air leakage.

Safety device verification: Test the sensitivity of overload protection devices (such as torque limiters), limit switches, and emergency stop buttons to ensure timely triggering under hazardous conditions.

Standard requirement: GB/T 3811-2008 stipulates that the error of the torque limiter shall not exceed ± 5%.

2. Monitoring during operation

Load monitoring: Real time observation of load values through the dashboard or display screen, prohibiting exceeding 90% of the rated load (with a 10% safety margin reserved).

Risk warning: When operating at an overload of 10%, the structural stress increases by 21% and the fatigue life decreases by more than 50%.

Temperature control: During summer operations, monitor the hydraulic oil temperature (usually not exceeding 70 ℃). If it exceeds the temperature limit, stop the machine for cooling to avoid oil deterioration.

Solution: Install a cooling fan or increase the number of oil circulation cycles to improve heat dissipation efficiency.

Abnormal response: If there are abnormal noises, vibrations, air leaks, etc. during operation, immediately stop the machine for inspection and prohibit operations with defects.

Case: A construction site caused a chain wheel to break due to abnormal noise caused by not stopping the machine, resulting in a falling object and injuring people.

3. Post operation maintenance

Cleaning and maintenance: After the operation is completed, use a dry cloth to wipe off the oil stains on the surface of the equipment, clean the condensed water in the gas supply pipeline, and prevent rusting.

Tip: Install an automatic drain at the end of the exhaust pipe to regularly drain accumulated water.

Lubrication supplement: Apply lubricating grease to the sprocket, drum, bearings and other parts, and choose wear-resistant and high-temperature resistant models (such as lithium based grease).

Dosage control: It is advisable to add the amount of old grease each time to avoid excessive dust adsorption.

Data recording: Establish equipment operation logs to record information such as load, running time, and fault phenomena, providing a basis for predictive maintenance.

Case: A certain enterprise replaced the brake with hidden dangers in advance by analyzing the operation logs, avoiding shutdown accidents.

3、 Long term idle stage: key measures for corrosion prevention and performance maintenance

1. Storage environment control

Dry and ventilated: The equipment should be stored indoors with a relative humidity not exceeding 70% to prevent metal parts from rusting.

Protective measures: In humid environments, use dehumidifiers or place desiccants (such as calcium chloride).

Temperature stability: The storage environment temperature should be controlled between -20 ℃ and 40 ℃ to prevent hydraulic oil from solidifying or seal aging.

Case: A northern enterprise failed to take insulation measures for idle equipment during winter, resulting in hydraulic oil solidification and damage to the pump body during start-up.

Dust cover: Cover the equipment with waterproof cloth or special cover to prevent dust and rainwater from entering the pneumatic system.

Standard requirement: The covering must have waterproof and dustproof functions, and maintain a distance of at least 10cm from the equipment to avoid friction damage.

2. Regular start-up and maintenance

Monthly start-up: For equipment that has been idle for more than one month, start it once a month and run it without load for 10 minutes to check whether the pneumatic system and brake are normal.

Key points of operation: Before starting, manually turn the car and confirm that there is no card lag before powering on.

Lubrication and maintenance: Add lubricating grease to key parts every 3 months to prevent bearings and sprockets from rusting due to long-term inactivity.

Case: A warehouse had rusted sprockets due to failure to lubricate idle equipment, and the entire set of transmission components needs to be replaced when it is put back into use.

Battery maintenance: If the equipment is equipped with a battery, it needs to be recharged once a month to maintain a battery level of over 50% and avoid sulfurization.

Technical parameters: The self discharge rate of lead-acid batteries is about 3% -5% per month, and long-term power loss can lead to capacity degradation.

3. Check before reactivation

Comprehensive testing: Equipment that has been idle for more than 6 months must undergo structural non-destructive testing, hydraulic system pressure testing, and electrical system insulation testing before being put back into use.

Standard basis: GB/T 6067.1-2010 stipulates that equipment that has been out of use for a long time must be tested and qualified by a professional organization before it can be put into use.

Trial operation: First, conduct a no-load trial operation to observe whether each component runs smoothly, then gradually increase the load to the rated value, confirm that there are no abnormalities, and then proceed with formal operation.

Case: A certain enterprise did not conduct a trial run of idle equipment and directly operated at full load, resulting in the fracture of the gearbox gear and a repair cost of up to 100000 yuan.

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