2.10.1 Basic Information
Lubrication of an air compressor is essential to reliable operation. Carbon and varnish can form in
compressor cooling oils. These deposits block the flow of lubricant and cause excessive wear and
failure of moving parts. Contamination of the lubricant can allow the formation of acids, causing ex‐
tensive internal corrosion. Water may be condensed decreasing the lubricity.
Lubricants in rotary compressors do much more than lubricate. During the compression process, it
acts as a sealant in the airend which is important for maximum efficiency. The lubricant also ab‐
sorbs much of the heat of compression to cool the airend and reduce the temperature of the com‐
pressed air. It’s not enough that a compressor cooling oil lubricates well, it must stand up to the
heat, pressure and contaminants that are present in every air compressor.
2.10.2 KAESER Lubricants
KAESER synthetic lubricants should be stored in a protected location to prevent contamination. Do
not re-use drums; flush and send to reconditioner.
Although the KAESER synthetic is not highly flammable, it will burn. While KAESER synthetic com‐
pressor cooling oil is less flammable than equal viscosity mineral oils, it cannot be classified as a
fire-resistant fluid. It has a flash point above 460 °F. Since the user has total control over the condi‐
tions of the compressor lubricant, he assumes total responsibility for its safe usage.
Material Safety Data Sheets are available for each lubricant from your authorized KAESER Service
representative.
Regardless of the lubricant selected, the KAESER SIGMA lubricants will separate readily from wa‐
ter. If condensate occurs it can easily be removed. Let the compressor sit so that any water can
drain back to the separator tank and separate to the bottom. See chapter 10.11 proper draining
procedure.
KAESER has several lubricants available that are specially formulated to match these demands.
They feature excellent lubricity, outstanding demulsibility (ability to separate from water), and long
life.
M-SERIES
■ M-Series SIGMA compressor cooling oils are semi-synthetic lubricants.
■ M-Series SIGMA compressor cooling oils are the highest quality petroleum lubricants. M–460
is specially blended to provide reliable performance in KAESER screw compressors.
S-SERIES
■ S-Series SIGMA compressor cooling oils are synthetic lubricants.
■ S-Series SIGMA compressor cooling oils are formulated from the most advanced synthetic lu‐
bricants. These ”synthetic” lubricants begin as high quality petroleum feed stock. They are then
refined, processed and purified into fluids with very consistent molecular structure. These oils
are carefully blended to produce extremely consistent lubricants with superior properties.
SIGMA synthetic lubricants feature all the advantages of both PAO and diester fluids.
■ S-460 lubricant is recommended for compressors operating in ambient temperatures between
40 °F and 105 °F.
2
Technical Data
2.10 Cooling Oil Recommendation
8
Operator Manual Screw Compressor
AIRTOWER 3C–7.5C Tri-Voltage
9_6917 34 USE
