Introduction of the difference between single-stage and two-stage rotary vane pumps

What is the difference between single-stage and two-stage rotary vane vacuum pumps ? The following will be explained in detail by Shanghai Bayu technical staff:

The basic difference between the lubrication methods of single-stage rotary vane vacuum pumps and two-stage rotary vane vacuum pumps is that they have different application ranges. Rather than the two-stage rotary vane vacuum pump itself having the ability to produce low ultimate pressures, the efficient fractionation in a two-stage rotary vane vacuum pump makes it more suitable for operation at low pressures ( less than 1 Torr) .

Single stage rotary vane pump

The pollution from oil decomposition eventually appears in atmospheric oils, and its effect on the first-stage performance is not too large, which means that the two oil changes can work satisfactorily for a long time. The use of gas ball helps to obtain the effect of purifying the oil, and at the inlet of the pump, only the air partial pressure of a few thousandths of Torr is increased , and the working noise is reduced. Even without a gas ballast, the noise level of a two-stage rotary vane vacuum pump is generally lower than that of a single-stage rotary vane vacuum pump. The hydraulic noise generated by the high oil flow rate at the atmospheric level does not exist at high vacuum levels. The low oil flow rate makes the two-stage rotary vane vacuum pump suitable for low pressure operation and is not suitable for continuous operation under high pressure.

Two-stage rotary vane pump

For large gas mass flows, when the oil in the high vacuum stage reservoir is exhausted, the oil cannot flow back into the pump chamber in the face of a strong gas flow. Therefore, when it is necessary to continue working under high pressure ( about l0 Torr or more ) , oil should be forcibly supplied for lubrication.

The lubrication system of the single-stage rotary vane vacuum pump is based on the differential pressure principle, and it works well at pressures below 500-600 Torr . When the inlet pressure is high, the gas backflow of the oil circuit prevents the oil from flowing, and only the mandatory oil supply can work continuously at a pressure of 500 Torr or more. Single-stage rotary vane vacuum pumps are usually considered to be equipped with oil separators when large mass flow rates must be handled.

Through the above introduction, do you know the difference between a single-stage rotary vane pump and a two-stage rotary vane pump? If you have any questions, please feel free to contact us!

" The difference between single-stage and two-stage rotary vane pumps" is provided by Shanghai Bashu. For more information on rotary vane pumps, please visit: