Paper 10: Lubrication of Air Compressors

There is an increasing use of pneumatic equipment in production and process industries and reliability of equipment in these industries is of paramount importance. The failure of an air compressor due to deficiencies in the lubricant can be very costly. In this paper important aspects of lubricant performance are discussed. The differences between the requirements of lubricants for rotary oil-cooled air compressors and for reciprocating air compressors are highlighted. Some of the requirements are conflicting and can cause problems if an oil is used in a type of compressor for which it is not designed. Mechanisms by which oil can cause failures are analysed. Some of the failures are common to certain types of compressor. Guidance is given which can reduce the risks of failures. This includes both design and operating instructions. Finally, full-scale methods of test for rotary oil-cooled and reciprocating air compressors are given, including a test method for very high-pressure reciprocating compressors; typical test results are supplied.