The common major faults or accidents of air compressor mainly include fracture fault and combustion explosion accident, and the following points are for reference.

1. Crankshaft fracture: during the heat treatment of the air compressor, the fillet was not treated, which caused stress concentration at the junction; The fillet processing is irregular, with local section mutation; The overload operation lasts for a long time, and the user increases the speed at will due to improper use, which worsens the stress condition; The quality of the material itself is defective. In addition, it can also be seen that the oil hole on the crankshaft cracks and breaks. Most of the fracture problems occur at the fillet transition between the journal and the crank arm.

2. Fracture of connecting rod: plastic deformation occurs when connecting rod screws are used for a long time; The eccentric load caused by the poor contact between the screw head or nut and the end face of the big head can be as large as seven times of the simple axial tension of the bolt. Therefore, there should be no slight deflection. At the same time, the contact should be evenly distributed, and the distance between the contact points is appropriate.

3. Piston rod fracture: it refers to the thread connecting the crosshead and the thread fastening the piston, which are the weak links of the piston rod and are easy to fracture. If there is no problem in ensuring design, processing and material, the preload shall not be too large during installation, otherwise the piston rod will break when the large force reaches the upper yield limit. After long-term operation, due to the excessive wear of the cylinder, the piston in the horizontal column will sink, resulting in additional load at the connecting thread. Further operation may break the piston rod, so special attention should be paid during maintenance.

4. Cracking of cylinder and cylinder head: For water-cooled machines, after running and stopping at low temperature, the cooling water in the cylinder and cylinder head is not completely iced and breaks the cylinder and cylinder head. Therefore, in the north of China, especially in low temperature areas, L must drain off the cooling water after stopping.

5. Combustion and explosion accidents: when the lubricating oil in the cylinder is not filtered well, the gas containing a lot of dust is sucked into the cylinder, forming carbon deposits and contacting with the gas containing a lot of volatile matter, causing explosion. In addition, before the gas load test run of the compressor, the explosion accident may also be caused if the air is not purged with low pressure nitrogen. The valve from the compressor to the air tank was not opened after driving, resulting in a sharp rise in the exhaust pressure and explosion.

As the high-pressure gas valve of the compressor is not tight, the gas returns to the cylinder under high temperature and pressure. When there is carbon deposit, it will cause an explosion accident. In order to avoid combustion and explosion accidents, the exhaust valve must be overhauled, the air leakage part must be checked, and the oil dirt in the gas tank and pipeline must be cleaned regularly to eliminate hidden dangers.