Air Compressor Oil

Air Compressor Oil

AIMS Industrial stocks air compressor oil for reciprocating piston compressors and rotary screw compressors — correct-grade lubricants that protect compressor components, maintain operating efficiency and extend service intervals. Using the correct compressor oil for the machine type and operating conditions is one of the most important factors in compressor longevity. The wrong oil — or an oil past its service life — causes increased cylinder wear, valve carbon deposits, bearing failure and elevated operating temperatures, all of which reduce compressor life and increase maintenance cost.

Reciprocating Compressor Oil

Reciprocating (piston) compressors use splash or pressure lubrication to oil cylinder walls, piston rings, crankshaft bearings and connecting rod bearings. Compressor oils for reciprocating machines are formulated with low carbon-forming tendency — standard engine oils and general-purpose lubricants deposit carbon on compressor valves and in discharge lines, creating a fire and explosion hazard in the compressed air system. Dedicated reciprocating compressor oils use hydrotreated mineral base stocks with additive packages that minimise carbon deposits and valve lacquering across the compressor’s operating temperature range.

Rotary Screw Compressor Oil

Rotary screw compressors inject oil directly into the compression chamber to seal the rotors, cool the compressed air and lubricate the rotor bearings. The oil is then separated from the compressed air in the separator vessel and recirculated. Rotary screw compressor oils are formulated for this demanding duty — they must maintain viscosity stability across wide temperature ranges, resist oxidation and foaming in the separator circuit, and provide good demulsibility for efficient oil-air separation. Extended-life synthetic rotary screw compressor oils allow drain intervals of 4,000 to 8,000 hours versus 1,000 to 2,000 hours for conventional mineral grades.

Viscosity Grades and Specifications

ISO VG 46 and ISO VG 68 are the most common viscosity grades for air compressor oils. ISO VG 46 is the standard grade for most reciprocating and rotary screw compressors operating at normal ambient temperatures. ISO VG 68 is specified for high-temperature environments and larger compressors with higher operating temperatures. Always refer to the compressor manufacturer’s service manual for the specified oil grade and change interval — deviating from the specification can void the equipment warranty.

Oil Change Intervals and Monitoring

Regular oil changes at the manufacturer’s specified interval are the single most important compressor maintenance task. Oil samples for condition monitoring — checking viscosity, acid number and particulate content — allow extended drain intervals on synthetic grades to be safely managed. AIMS stocks compressor oil in the grades and pack sizes suited to both workshop and industrial-scale compressor maintenance. For help selecting the right oil for your compressor make and model, contact our team. AIMS Industrial has been supplying industrial lubricants across Australia since 1988.