What Oils to Use in an Air Compressor

Air compressors use oil to lubricate moving parts.

Different types of air compressors have different working parts, and may require one or more types of oil. Compressor oil is also used in the pressurized spaces within the compressor.

Reciprocating Compressors

Reciprocating compressors require lubrication for the bearings, pistons, rings, cylinders and valves. The type of oil used must not be carbon-forming and should contain anti-wear additives.

Screw Compressors

Screw compressors can be geared or non-geared. With geared models, lubrication is needed for bearings and gears and to act a sealant between rotors. This type of air compressor requires low-foaming oil with a high resistance to oxidation.

Rotary Vane Compressors

Rotary vane compressors are either water-cooled or oil-cooled. In water-cooled systems, oil is fed mechanically to the rotor and bearings in metered quantities. Both systems require oil that is able to withstand severe oxidizing and contains good demulsibility. A low-volatile oil is recommended for use in oil-cooled systems.

References

• AZO Materials: Compressor Oils -- Supplier Data by Castrol