The working principle of centrifugal pump
Impeller installed in the pump housing, and tighten in pump shaft 3, pump shaft directly driven by motor. Shell has a central pump suction pipe and liquid inhaled 4 5 connection. The liquid bottom valve 6 and into the pump suction pipe inside. The pump housing liquid row 8 and discharge tube export 9 connection.
In before starting the pump, the pump housing fill is conveying of liquid. After the start, driven by high speed rotating impeller shaft, between the blades with the liquid must also be turning.
    In the centrifugal force under the action of fluid from the impeller center has been thrown outside and get energy to the left into the volute pump impeller outer shell. In the diffuser, because the flow of liquid expanded and slow, and will be part of the kinetic energy for static pressure can, and finally by higher pressure into the discharge pipe, send to the need to place. The liquid flow by impeller center outside, in the center of the impeller formed some vacuum, because the holding tank above the surface of the pressure is greater than the pump pressure at the entrance, liquid are continuous pressure into the impeller. Visible, if the impeller constantly rotation, the liquid will constantly under inhaling and exhaling.
 
water pump manufacturers  : http://www.pumpchinapump.com