Compressor Oil: Properties and Removal of Impurities

compressor oil

Compressor oil is used in the industry as a lubricant for the valves and cylinders of compressors; it is also used as a sealing medium for compression chamber and piston rods.

The main feature of that distinguishes compressor oils from other industrial oils is their operation in high-temperature environments and mixing with coolants. Therefore, compressor oils need to meet stringent requirements regarding chemical and thermal stability, as well as viscosity at low temperatures.

Compressor oils can be medium-load and heavy-duty. The medium-load air compressor oil doesn’t have additives. The heavy-duty compressor oil is produced from sulfur and low-sulfur petroleum by deep selective refining, followed by mixing with special additives, oxidation inhibitors, corrosion inhibitors, antiwear additives, etc.

When selecting a particular oil, it is necessary to pay attention to pour point (must be low), viscosity index (must be high), the possibility of chemical interaction with a coolant, their mutual solubility, and corrosion activity of the mixtures.

The parameters of HA-23 and HF-12-16 compressor oils (Table 1).

Table 1




Kinematic Viscosity at 50ºС, мм/с2 22-24 18
Acid number mg KOH / g, max 0,07 0,03
Sulphated Ash content,%, max 0,005
Temperature ° C
flash point  °C, (min) 175 160
pour point °C, (max) -38 -40
Oxidation resistance
Sludge content,%, max 0,02 0,005
Acid number after oxidation, mg KOH / g, max 0,6

Purification of compressor oils

Compressor oils containing water, solids and dissolved gases have significantly degraded performance properties. Their use therefore is highly undesirable. But it does not mean that the life cycle of the oil ends.

GlobeCore developed plants for purification and regeneration of compressor oils which remove water, dissolved gases and mechanical impurities. After processing, the compressor fluid has the initial properties, and can be reused for its intended purpose.

Сompressor oil purification equipment from GlobeCore:

  • Reduces water content to 10 ppm or less;
  • Reduces air content not 0.25% or less (vacuum degassing);
  • Removes solid impurities to 1 micron;
  • Extends lifetime of oil and compressor;
  • Increases efficiency of compressors;
  • Reduces downtime.