What Causes Oil Contamination ?
Air compressor oil is more than simply a lubricant. It
also serves to dissipate heat and to flush away dust and metal particles
that are detrimental to bearings and gears. Contaminants in the oil though
can greatly affect the life of the lubricant.
External Contaminating Factors
One of the greatest contributors to to the degradation of the
oil is oxygen, which is introduced into the compression chamber, and is by its
very nature an oil contaminant. The oil additives must be able to handle
the oxidation inherent in a piece of equipment designed to create air from an
air-oil mixture. Along with ambient air, water vapor is drawn into the
compressor in the form of humidity, which also acts as a contaminant. In
addition, dust is drawn into the unit, which in small quantities will bypass the
inlet filter and contaminate the lubricant. Air, water and dust are all
very normal contaminating products that have adverse effects on overall oil
Compressor oil also is affected by unique or extreme
environmental conditions. These include industrial pollution that can be
chemical reactants in the oil, as well as chemical vapors. The life of the
compressor is dependent on the oil, and the oil is dependent on its environment.
Internal Contaminating Factors
Air compressor oil is also affected in many ways by entrained
products, which act as catalysts and reactants to break down the oil. Rust
and wear metals from the internal components of the compressor are common oil
contaminants, that can greatly reduce lubricant life. Acids formed from
gas vapors drawn into the unit are another contaminant with which the oil
additive packages have to contend. Additionally varnish and sludge can
form from chemical reactions in the oil, which can greatly reduce the life of
the oil, and the heat transfer abilities of the compressor itself.
As all of these types of contaminants are introduced or formed
in the oil, the life of the oil is reduced. This is the reason that
oil analysis is the key to maintaining
your compressed air system.