Rotary vane pumps are used in a variety of industries by both large and small manufacturers and by individual designers and craftsmen. They are play a role in production of materials and the handling of materials at every stage from the formation of raw materials to the handling and packaging of finished products. These pumps are a vital part of a surprising number of products. Still, many find themselves wondering, what is a rotary vacuum pump?

Rotary vane pumps are typically an oil-sealed rotary displacement pump although they can be dry pumps as well. Rotary vane vacuum pumps are made both in single- and two-stage versions. Rotary vane vacuum pumps are also built in single- and two-stage versions. Depending on the needs of the user they can decide which lends itself best to their application. Typically a two-stage pump will achieve lower pressures than a single-stage pump. When considering which is best for you consultation with an expert in the field can be helpful.

In general, the basic design of a rotary vane vacuum system usually consists of the pump housing, the installed rotor, vanes that converge to a common center under spring force and an inlet and outlet. There are two openings in the housing; the outlet valve is oil-sealed while the inlet valve is designed as a vacuum safety valve. The vacuum safety valve is always open during operation. These parts are inside the working chamber that is located inside the housing.

The rotor and the vanes divide the working chamber into two separate spaces that have variable volumes. As the rotor turns it the trapped gas flows into a suction chamber until it is sealed off by the second vane. Then the enclosed gas is compressed until the outlet valve opens aligned with atmospheric pressure. In a gas ballast operation, a hole to the outside is then opened to empty into a sealed suction chamber on the front side of the pump.

Some types of rotary vane pumps can be equipped with a vacuum safety valve as well. The safety valve can disconnect the pump from the vacuum recipient if there is an intentional or unintentional stoppage. Using the displaced gas to vent the pumping system it will prevent oil from rising into the recipient. Then, when starting the pump, it opens after the stoppage once the pressure in the pump has again reached the same pressure in the recipient.