In use lubricating oil becomes contaminated by unwanted particles in various forms

• Carbon deposits,
• Oxidation by-products
• Metallic particles

Crucial role in “cleaning” the contaminated lubricant and extend its life is the purification through a centrifugal separator.
The efficiency of the centrifugal separator is generally not reflected in the routine lube oil analysis (viscosity, BN, etc.). For instance, the comparison of the analysis results of lube oil samples drawn before and after the centrifugal separator, may reveal no differences. This can lead to the wrong interpretation and conclusion that the centrifugal separator is not working correctly.
Therefore further to routine analysis, one method to demonstrate that the centrifugal separator is cleaning the oil effectively is to measure the number of particles in relation to the particle size.
The centrifugal separator should be in continuous operation as the engine is running in order to ensure removal of contaminants as quickly as possible.
If possible, the centrifugal separator should be in operation also when the engine is shut down to further reduce the level of contaminants. In the latter case, oil temperature for efficiency separation needs to be maintained through heaters. Those installations with their separation plant shut down during engine stop, should consider re-starting the separator prior to engine start-up because contamination (engine leaks, condensation) could have occurred during engine stop.
It is important that maintenance and operation of the centrifugal separator is done according to the recommendations of the manufacturer.