Summary of common faults and maintenance suggestions for pneumatic hoists during operation

1、 Power system malfunction

No gas supply or insufficient air pressure

Phenomenon: The hook cannot rise/fall, or the speed is abnormal.

Reason: Interruption of compressed air supply, low intake volume, incorrect or leaking gas supply pipeline connection.

Case: A construction site experienced a complete shutdown of the pneumatic hoist due to the detachment of the gas supply pipeline. After maintenance, it was discovered that the pipeline was aging and cracking.

Maintenance suggestion:

Check the connection of the gas supply pipeline daily to ensure it is secure, and use soapy water to detect any leaks.

Test the compressed air pressure every month to ensure it meets the equipment's requirement of 100psi (refer to the equipment manual for specific pressure).

Regularly replace aging hoses and avoid using non-standard accessories.

Handle control valve malfunction

Phenomenon: When operating the handle, the hook does not respond or the speed is not adjustable.

Reason: The throttle control lever is stuck, the speed control valve is not calibrated correctly, and foreign objects are stuck in the valve body.

Case: A certain enterprise almost caused a collision accident due to the uncontrolled lifting of the hook caused by metal debris entering the handle control valve.

Maintenance suggestion:

Clean the handle control valve weekly and blow away the dust inside the valve body with compressed air.

Calibrate the speed control valve quarterly to ensure that the speed adjustment range meets the equipment parameters.

Avoid excessive force during operation to prevent damage to the internal components of the valve body.

2、 Mechanical structural failure

Hook system malfunction

Phenomenon: Hook deformation, opening wear, fatigue cracks.

Reason: Overloading use, long-term fatigue, material defects, high temperature environmental thermal radiation.

Case: A steel plant operated in a high temperature environment above 300 ℃ without taking insulation measures for the hook, resulting in deformation of the hook opening and falling of the lifted object.

Maintenance suggestion:

Check the surface of the hook daily for cracks and conduct regular inspections using a magnetic particle flaw detector.

Replace immediately when the wear exceeds 10% of the dangerous section, and repair welding is prohibited.

Insulation boards should be installed in high-temperature workplaces to prevent hooks from being directly exposed to thermal radiation.

Transmission component malfunction

Phenomenon: Chain/sprocket jamming, brake failure, drum fatigue cracks.

Reason: Insufficient lubrication, foreign objects entering, overload use, aging brake spring.

Case: A logistics warehouse failed to lubricate the sprocket in a timely manner, resulting in the ring chain getting stuck. After forced operation, the sprocket teeth broke.

Maintenance suggestion:

Add lubricating grease to the sprocket and drum every week, and choose models that are resistant to high temperatures and wear.

Adjust the brake clearance monthly and replace aged springs to ensure reliable braking.

Disassemble and inspect the drum every six months, and replace it immediately if cracks are found. Welding repair is prohibited.

3、 Control system malfunction

Safety device failure

Phenomenon: Overloading protection not triggered, limit switch failure, anemometer false alarm.

Reason: Sensor contamination, short circuit in the circuit, incorrect parameter settings.

Case: A construction site failed to verify the torque limiter, resulting in the failure of the protective device to operate when the suspended object was overloaded, leading to structural overturning.

Maintenance suggestion:

Clean the sensor contacts monthly and use an alcohol swab to remove oil stains.

Calibrate safety device parameters quarterly to ensure they match the rated load of the equipment.

Every year, professional institutions test the sensitivity of safety devices and issue qualified reports.

Electrical system malfunction

Phenomenon: Abnormal dashboard indicator lights, false alarm sounds, controller crashes.

Reason: Line aging, insulation damage, low software version.

Case: A factory's electrical circuit was bitten by a mouse, resulting in a short circuit and fire that destroyed the control cabinet.

Maintenance suggestion:

Check the appearance of the electrical circuit daily, and immediately wrap it with insulating tape and replace it if any damage is found.

Before the rainy season, waterproof the lines and install protective sleeves.

Upgrade controller software annually, fix known vulnerabilities, and improve system stability.

4、 Malfunctions caused by environmental factors

Corrosion issue

Phenomenon: Corrosion of metal structures, aging of seals, and peeling of coatings.

Reason: Unprotected outdoor operations, salt spray corrosion in coastal areas, improper use of cleaning agents.

Case: A certain port equipment was forced to undergo major repairs due to a 40% decrease in structural strength after 3 years of use, as it was not coated with anti rust paint.

Maintenance suggestion:

Outdoor equipment should be coated with weather resistant anti rust paint and reapplied every two years.

Avoid using strong acids or alkalis during cleaning and choose neutral cleaning agents.

When the equipment is not in use for a long time, it should be stored in a dry and ventilated place, covered with rainproof cloth.

Temperature influence

Phenomenon: hydraulic oil viscosity decreases, lubricating grease solidifies, and battery performance deteriorates.

Reason: High temperature in summer, low temperature in winter, and no temperature control measures taken.

Case: A construction site in northern China failed to adjust the electrolyte density of the battery during winter, resulting in the battery freezing and cracking, and the equipment being unable to start.

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