Cetus® PAG is a synthetic compressor oil based on polyalkylene glycol. It is designed for use in reciprocating compressors for chemical and hydro-carbon gases, including natural gases such as LNG and LPG. Because the solubility of these gases in Cetus PAG is low, the oil maintains its viscosity, unlike mineral oil base lubricants which will dilute.

Cetus PAG is recommended for lubrication of the cylinders and/or crankcase bearings of reciprocating compressors for multiple gases, including natural gases such as: methane and ethane; petroleum gases such as propane and butane; hydrocarbon chemical gases such as ethylene, propylene and butylene; and chemical gases such as ammonia, butadiene, vinylchloride and dry inert gases. Cetus PAG easily mixes with water, therefore contact with humid air should be avoided. Cetus PAG contains polyalkylene glycols and is not compatible with mineral oil or other synthetic fluids. When changing to or from Cetus PAG, the oil system should be completely drained and thoroughly flushed. Cetus PAG does not affect common seal and gasket materials such as butyl, nitrile, neoprene, fluoro-elastomers (e.g. Viton) and fluoro-silicones. Ordinary industrial paints soften in the presence of this oil. Two-pack epoxy formulations are normally resistant.