The Roots vacuum pump (i. E. Roots pump) is aso called mechanical booster. As its work principle, please refer to working principle of the Roots pump.

The best advantage of the Roots vacuum pump is the higher suction capacity under the lower suction pressure. But it can't be used seperately and a fore pump should be connected with it in series. While the pressure of the container pumped by the fore pump is close to the suction pressure of the Roots pump, the Roots pump begins to work. In general, the high pressure difference is not allowed by the Roots vacuum pump. Otherwise, the pump will be damaged for overloading or overheating. So a suitable fore pump and the protective equipment are needed to connect with it.

The fore pump is usually used the oil seal mechanical pump or liquid ring vacuum pump. Especially when pump the gas containing a great deal of steam, the water ring vacuum pump is the ideal product being as the fore pump.