Rotary vane vacuum pumps consist of two moving parts - a rotating hub mounted eccentrically in a casing and two or more sliding vanes housed within this hub. As the hub rotates within the casing, the vanes are thrown out against the casing wall, thus dividing the space between the rotating hub and the casing wall into segments. The suction fluid is pulled into the pump be the expanding segments and then compressed before discharge. Rotary vane pumps can be used as vacuum pumps or as low and medium pressure compressors, can be oil-less, drip oil, oil metered, or oil flooded in design.
Single stage dry rotary vane vacuum pumps will produce pressures down to 25"HgV, where drip oil machines will produce pressures down to 27"HgV and oil flooded single stage pumps will produce 29.9"HgV. 2-Stage rotary vane vacuum pumps can produce pressures as low as .0004mm. Single stage rotary vane compressors can produce anywhere from 10psig to 150psig and 2-stage compressors will produce up to 300psig.