Oil out of the screw air compressor outlet

The solution here is to check and clean the unidirectional valve, replacing it when necessary. Improper installation or blockage of the oil return pipeline will impede the normal return of the lubricating oil. [pdf]

Screw air compressor serious oil leakage

First, check that there isn't a very high air demand, or air leak somewhere. If the capacity of the air compressor is really too low, check the following: Check differential pressure over oil separator. Replace separator when necessary. Check and replace compressed air filters (if installed). [pdf]

Oil injection screw air compressor processing

When the inlet/unloader valve is open, the air enters the compressor screw element. The screw element works like a pump and it compressed the air. During this process, oil is injected in the element. The oil is there to cool the air, as the air gets very hot during compression. [pdf]