Single-stage rotary vane vacuum pump and double rotary vane vacuum pump lubrication method is the basic difference between their different scope of application. Rather than double rotary vane vacuum pump itself has the ability to produce low ultimate pressure than double rotary vane vacuum pump in efficient fractionation effect to make it more suitable for working under low intensity (less than 1 torr).
Decomposition of oil pollution from the final to appear in the oil level in the atmosphere and its effect on the performance of the first level is not too big, which means that the two oil change between a long time can work satisfactorily. Using gas ballast will help to get the oil purification effect, and at the entrance of the pump, will only add a few parts per thousand Torr, partial pressure of air at the same time reduces the noise in work. Even in the absence of town gas, double rotary vane vacuum pump noise level generally lower than the single-stage rotary vane vacuum pump. The high rate of oil flow in the atmospheric level of hydraulic noise, in the high vacuum stage does not exist. Low oil flow rate makes the double rotary vane vacuum pump is suitable for working under low pressure, and not suitable for continuous work under high pressure.
For large gas mass flow, when the high vacuum level if run out of oil reservoir, in the face of strong turbulence, oil is not backwash of flow into the pump chamber. So, when must be under strong pressure (about l0Torr above) continues to work, should be mandatory to provide oil for lubrication.
Single-stage rotary vane vacuum pump lubrication system is based on the differential principle, it is in less than 500-600 torr under pressure, can work well. When the inlet pressure is higher, the oil gas reflux blocked the flow of oil, only mandatory oil in more than 500 torr under the pressure of work continuously. When must deal with large mass denier flow rates, single-stage rotary vane vacuum pumps usually consider set up oil and gas separator.