The rotary vane pump is an oil-sealed rotational displacement pump. The pumping system is made up
of the housing, the eccentrically mounted rotor, and the centrifugally- and spring-loaded radially sliding
vanes, which divide the suction chamber into multiple chambers. The volume of each chamber changes
periodically as the rotor rotates. This causes the gas to be drawn in at the vacuum flange and com-
pressed in the suction chamber by the rotation of the rotor, until the exhaust valve opens against the
atmospheric pressure at the outlet and expels the gas. The exhaust valve is oil-sealed. When the valve
opens, a small quantity of oil penetrates into the suction chamber. In addition to lubrication, this also
causes the gaps between the rotor, stator and vanes to seal.
Vacuum safety valve
Depending on the pump type, rotary vane pumps are equipped with a vacuum safety valve. This sepa-
rates the rotary vane pump from the vacuum chamber in the event of intentional or unintentional stand-
still, and vents the pumping system with the displaced gas so that oil does not rise into the vacuum
chamber. After switching on, the valve opens after a delay.
Gas ballast valve
The gas ballast device is used to blend ambient air or inert gas with the process gas in the pumping
system. The increase of air content compresses and expels a pumped gas-vapor-mixture within specific
limits, without causing condensation in the suction chamber.
Operating fluid, oil
The pump oil, also known as operating fluid, fulfills various tasks in a rotary vane pump:
● lubrication of all moving parts
● filling part of the dead volume under the exhaust valve
● sealing the gap between the intake and exhaust channel, and between the vanes and the working
chamber
● ensuring an optimal temperature balance through heat transfer
Product description
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