A water pump is a machine that transports or pressurizes a liquid. It transfers the mechanical energy of the prime mover or other external energy to the liquid, increasing the liquid energy, and is mainly used to transport liquids including water, oil, acid-base liquid, emulsion, suspoemulsion and liquid metal. According to the different structural principles, the water pump can be divided into various types such as centrifugal pump, axial flow pump, mixed flow pump and so on.

Centrifugal pumps work by rotating the impeller to cause centrifugal motion of water. Before the pump is started, the pump casing and the suction pipe must be filled with water, and then the motor is started, so that the pump shaft drives the impeller and the water to rotate at a high speed. into the pressurized water line of the pump.

Axial flow pump is a type of pump that conveys liquid along the axis direction by the force generated by the blades of the rotating impeller on the liquid. There are several types of vertical, horizontal, inclined and tubular.

Mixed flow pump is a kind of pump between centrifugal pump and axial flow pump. The specific speed of the mixed-flow pump is higher than that of the centrifugal pump and lower than that of the axial-flow pump, generally between 300-500. Its lift is higher than that of the axial flow pump, but the flow is smaller than that of the axial flow pump and larger than that of the centrifugal pump.