Cause analysis of cracks in air compressor parts and its methods of inspection and maintenance

2023-12-01

Common causes of cracks in air compressor parts are:

(1) The cooling water in the cylinder head of the air compressor is frozen because it is not drained in time after stopping in winter;

(2) Due to the internal stress produced during casting, it gradually expands obviously after vibration in use;

(3) Due to mechanical accidents, such as piston rupture and connecting rod screw breaking, the connecting rod breaks off and falls off, or the balance iron on the crankshaft flies out to damage the air compressor or parts fall off during gas cutting to top the cylinder head.

The inspection and maintenance methods after cracks appear are as follows:

(1) Kerosene penetration method: The inspection process is to wipe the air compressor body and cylinder head with a cotton yarn head soaked with kerosene, and then wipe the places where cracks may occur with a dry cotton yarn head, and immediately draw white powder on these places. At this time, kerosene will penetrate into the white powder where there are cracks, and the location and length of cracks will be clearly displayed.

(2) Hydrostatic method: Hydrostatic method is to check the crack position by increasing the cooling water pressure. The water pressure inspection is carried out on a special equipment-water pressure tester. In enterprises with poor equipment environmental conditions, some simple equipment can be inspected by using ordinary hand-operated pumps. That is to say, try to block the water pipe joints of the air compressor body or cylinder head first, and only connect one of the water pipe joints with the water outlet of the water pump with a rubber hose. The upper plane of the machine body should use a special cover plate with the same size, so that the cooling water cannot overflow. Then turn on the switch to press the water pump, make water enter the cooling water jacket. Turn off the switch after water comes out, and continue to press the water pump until the pressure gauge pointer reaches 3-4 atmospheres, and then stop the water supply. At this time, the existence of cracks can be judged by checking whether there is water leakage or water seepage in the air compressor body and cylinder head.