Invoil 20 is the standard mechanical pump fluid used in applications involving corrosive or reactive gases.  This fluid has been distilled to remove the majority of the light fractions present in all raw material feedstock.  The removal of these fractions slows the degradation process and reduces the rate of sludge accumulation in the mechanical pump.  Actual field use indicates that Invoil 20 tends to extend the useful service life of the fluid anywhere from 5 to 10 times that of standard hydrocarbon fluid.  Invoil 20 can also be used as diffusion pump fluid.  This represents a great advantage by allowing users to establish a homogenous system and thus prevents any cross-contamination.