Air compressor oil filter also called air compressor lubricating filter. When compressed air, the oil injected will mix with air, thus introducing new impurities. The compressor oil filters filter the metal particles and impurities in the special oil of the air compressor, so that the oil entering the main engine is very clean, so as to protect the safe operation of the main engine. Impurities in engine oil are mainly metal debris, colloid, air, water and dust impurities mixed in the outside caused by moving friction