Causes of cracks in parts of high pressure screw air compressor

What are the causes of cracks in high pressure screw air compressor parts? How to check?
Common causes for cracks in parts of high-pressure screw air compressor are as follows:

(1) The cooling water is in the cylinder head of the engine block, which is frozen because it is not drained in time after shutdown in winter;

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

(3) It is caused by mechanical accidents, such as piston fracture, connecting rod screw fracture, resulting in connecting rod fracture and falling off, or the balance iron on the crankshaft flying out to damage the engine body, or the parts in the gas cutting fall off to top the cylinder head, etc.

The inspection methods are as follows:

(1) Kerosene penetration method: during the inspection, first wipe the machine body and cylinder head with a cotton yarn soaked in kerosene, and then wipe off the suspected cracks with dry cotton yarn and kerosene, and immediately paint the white powder on the drawing. At this time, kerosene will penetrate into the white powder where there are cracks, and the position and length of the cracks will be clearly displayed.

(2) Water pressure method: the water pressure method is to check the crack position by increasing the cooling water pressure.

In the repair shop with good equipment conditions, the hydraulic inspection is carried out on the special equipment - hydraulic tester. In units with poor equipment conditions, some use ordinary hand pressure water pumps to make simple equipment. During inspection, try to block the water pipe joints of the machine body or cylinder head, and only connect one of the water pipe joints with the water outlet of the water pump with a rubber pipe. The upper plane of the machine body should use a special cover plate with the same size to prevent the cooling water from overflowing. Then turn on the switch to press the water pump, and the room water enters the cooling water jacket. Turn off the switch after the water comes out of the switch, continue to press the water pump, and stop the water supply when the pointer of the pressure gauge reaches 3-4 atmospheres.


At this time, you can carefully check whether there is water leakage or seepage at the top, bottom, inside and outside of the cylinder head of the screw air compressor.