Vacuum Technology

Capacities are available from 100 to 70,000 cu ft per minute, operating usually in the pressure range of 10 to 10-3 torr. The peak speed of the pump is developed in the pressure range of 1 to 10-2 torr, the speed at the lower end of the pressure range depending on the type of forepump used. A typical mechanical booster utilizes two figure-eight-shaped impellers, synchronized by external gears,