The definition of a dry vacuum pump is a pump that will not use any fluids to make a vacuum or contact the process gas and will also discharge to atmosphere. … Timing gears with essential oil reservoirs and close clearances between your rotors and housing are additional attributes that make up a dry vacuum pump.

Principle of Operation

Dried out screw vacuum pumps operate with two screw rotors rotating in opposite directions. This traps the moderate to become pumped between the cylinder and the screw chambers and transports it to the gas discharge. … It also results in a lesser heat load of the compressed gas.