F
OR
M
ODELS
: JGI, JGM, JGN, JGP
AND
JGQ
S
ECTION
4 L
UBRICATION
PAGE 4-5
P
OLYALKYLENE
G
LYCOLS
(PAG)
•
Very good lubricant for high pressure applications
•
Does not foul reservoirs. Excellent for any reinjection application
•
Resistant to hydrocarbon gas dilution
•
Most are water soluble, verify application with lubricant supplier
•
Not compatible with mineral or PAO oils, some plastics and paints
•
Requires complete system flush when changing to or from mineral or PAO oils
•
Compatible with Viton and HNBR
•
Poor inherent oxidation stability and corrosion protection - requires additives
•
Not recommended for air compressors.
•
Very high viscosity index, greater than 200
Lubricant Formulations
Many different oils are made from the same type of base stock by changing the additives.
Most oils can be formulated with either a mineral oil base or a synthetic base. The types of
additives can significantly alter the lubricant's physical characteristics and suitability for it's
intended service. Additives can account for up to 30% of the volume of the oil.
Compounded Cylinder Oils
Compounded oils are formulated for use in steam cylinders and/or compressor cylinders.
These lubricants enhance oil film strength to counter the effects of water, wet gases, sol-
vents, etc., present in the gas.
Additives can be animal or vegetable fats, or synthetic based. Animal and vegetable based
additives have a very low oxidation resistance and do not perform well at high temperatures.
However, most compounded oils today use some type of synthetic chemical instead of the
natural additives. Compounded oil should not be used in the compressor frame. Historically,
the additives have not been compatible with lead based bearing materials.
R&O Oil
Rust and oxidation inhibited (R&O) oil is a very simple oil comprised of base stock, corrosion
inhibitors, anti-wear and antioxidant additives. The viscosity of the base stock determines
the viscosity of the finished product. This oil is a very good selection for use in the compres-
sor frame and for most force feed systems.
Engine Oil
Engine oil is formulated for use in internal combustion engines. Its purpose is to counteract
the negative effects of combustion and help keep the products of combustion (heat, soot,
water, CO
2
) away from the moving parts of the engine. It is designed to attract water and
soot and help keep it in suspension until it can be removed by the filter. These qualities are
