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    Because the functions of all kinds of vacuum pumps are different except that they can satisfy the common point of vacuumizing the container. Therefore, it is very important to define the operation tasks of the pump in the vacuum system. The functions of the pump in various operation fields can be summarized as follows

1) To be the main pump in the system

    The so-called main pump is a vacuum pump which directly vacuumizes the vacuum system to obtain the vacuum degree required by the process requirements.

2) Crude pump

    Crude pumping pump is a kind of vacuum pump which can start to work when the pressure of vacuum system drops from atmospheric pressure to another pumping system.

3) Front stage pump

    The pressure of the other stage used to keep the previous stage of the vacuum pump below the allowable level.

4) Holding pump

    Holding pump refers to when the vacuum system is very small, can not be useful to use the main front stage pump. In order to maintain the normal operation of the main pump or to maintain the low pressure vacuum pump required by the evacuated container, another auxiliary front stage pump with low pumping speed is equipped in the vacuum system.

5) Crude vacuum pump or low vacuum pump

    Crude and low vacuum pump is a kind of vacuum pump which starts from the atmosphere and operates in the range of low vacuum or rough vacuum pressure after reducing the pressure of the pumped vessel.

6) High vacuum pump

    High vacuum pump refers to the vacuum pump operating in high vacuum scale.

7) Ultra high vacuum pump

    Ultra high vacuum pump refers to the vacuum pump operating in ultra-high vacuum scale.

8) Booster pump

    Booster pump usually refers to the vacuum pump operating between low vacuum pump and high vacuum pump, which is used to improve the pumping volume of the pumping system in the middle pressure range or to reduce the pumping rate requirements of the previous stage pump.