Number of stages:
The PRD-series three-lobe rotary piston vacuum pumps are highly developed products which can be used in a large variety of applications where it is necessary to convey important flows while keeping vacuum levels of up to 120 Torr (abs.).
Based on a pre-intake of auxiliary atmospheric air, but maintaining the basic principle of positive displacement, the operating cycle permits reaching higher vacuum levels with a single compression stage.
Volumetric displacement normally ends when gas is compressed and the compression chamber of the pump opens onto the discharge mouth.