Main pump: used in a vacuum system to get the required vacuum;
Roughing vacuum pump: lowering the pressure of the system from atmospheric pressure to a vacuum in which another pumping system begins to operate;
Backing vacuum pump: used to maintain the front stage pressure of another pump below its critical front stage pressure;
Holding vacuum pump: when the gas to be pumped is of small quantity, holding vacuum pump is used to maintain the vacuum pressure instead of operating the backing pumps;
Rough/Low vacuum pump: vacuum pump starting from atmospheric pressure and used to obtain low vacuum;
High vacuum pump: vacuum pump working in high vacuum conditions;
Ultrahigh vacuum pump: vacuum pump working in ultra-high vacuum conditions;
Booster vacuum pump: installed between a low vacuum pump and a high vacuum pump to improve the system efficiency or
reduce the capacity requirements of the front stage pump;