Monitoring compressor oil contamination and component wear should include testing viscosity, total acid number, particle count, water separability and analytical ferrography to effectively predict component failure.
Rotary Screw Compressors
The bearings and gears within rotary screw compressors require proper lubrication for metal protection, cooling and optimum rotor performance. High operating temperatures and water ingression can cause oxidation that can be damaging to metal surfaces. Compressors operating under these conditions typically use synthetic oils with additive packages that resist oxidation and prevent the formation of acids caused by lubricant degradation.
Reciprocating Compressors
Reciprocating compressors are highly efficient at attaining high pressures but are significantly larger and more difficult to maintain than rotary screw compressors. These units require lubricants with high thermal stability and the ability to control the formation of degradation deposits on metal surfaces.
Centrifugal Compressors
Centrifugal compressors operate at high speeds with a low tolerance for contamination ingression which can quickly cause severe damage to internal components – bearings, gears, impellers. Testing should be done to confirm that the correct lubricant type and grade is in use and to monitor its condition to prevent the formation of varnish and other degradation deposits.
