Multistage pump

　　Multistage pump

　　Multi stage pump is a kind of centrifugal pump which combines the inlet and outlet sections and the middle section through the pull rod. Its output water pressure can be very large, and it also depends on the rotation of the impeller to obtain the centrifugal force, so as to reduce the material loss. When the gas density reaches the working range of the mechanical vacuum pump, it is pumped out, so as to gradually obtain a high vacuum.

　　The multi-stage pump realizes suction, compression and exhaust by changing the volume of the pump chamber, so it is a variable volume centrifugal pump.

　　The basic structure of the pump is composed of water inlet section, water outlet section, middle section, tail cover, impeller, pump body, pump shaft, bearing, sealing ring, stuffing box and other components.

　　1. The impeller is the core part of the multi-stage pump. It has high speed and large output. The blades on the impeller play a major role. The impeller should pass the static balance test before assembly. The inner and outer surfaces of the impeller shall be smooth to reduce the friction loss of water flow.

　　2. Water inlet section, water outlet section and middle section are also called pump casing, which is the main body of multi-stage pump. It plays a supporting and fixing role and is connected with the bracket for installing the bearing.

　　3. The function of the pump shaft is to connect with the motor through the coupling to transmit the torque of the motor to the impeller, so it is the main component to transmit mechanical energy.