Info Centre >> Fuel and Lube Oil Technical Manual >> 7. Lube Oil - Test Results >> 7.5 Compressor Oil
Compressor Oils
Compressor oils include Air Compressor Oils , Gas Compressor Oils and Refrigeration Compressor Oils .
The table below shows the key test parameters for Viscosity,
Water, Insolubles and TAN.
Test Equipment for Gearbox Lubricants & Compressor Lubricants
| Compressor Oil | |||||||||||||||||||
Key Test Parameters |
Oil Condition |
Default Limit |
Comment |
||||||||||||||||
Viscosity (cSt at 40°C) |
Satisfactory | < +/- 15% | A viscosity increase is more common than decrease. It should be noted and checked at more frequent intervals. Check that the correct grade of oil is used for top-up. | ||||||||||||||||
z |
Borderline | nom >15-20% | |||||||||||||||||
Water (%) |
Satisfactory | 0.05% - 0.10% | Water can enter the oil via the compressor cylinders; always check that inter-cooler drains are operated effectively. Refrigeration oils cannot tolerate water at all. | ||||||||||||||||
s |
Exceeds limit | > 0.10% | |||||||||||||||||
Insolubles (%) |
Exceeds limit | > 0.10% | Formed by carbon from oxidised oil, high insolubles will rapidly foul air delivery valves. | ||||||||||||||||
TAN (mg.KOH) |
Exceeds limit | Change of 1.0 TAN | TAN should always be monitored by trend as the TAN of some oils can fall from new then rise again as the oil ages. | ||||||||||||||||