The main features of the power pump is: ①certain pump head at a certain speed has a limited value. Operating point flow and shaft power depend on the condition of the system of the system connected to the pump (potential difference, pressure difference and line loss). Head changes with the flow. ② work stable, continuous delivery, flow and pressure pulsation. ③ generally no self-absorption capacity, the need to pump the first filled with liquid or pipe pumping to a vacuum before starting work. ④ centrifugal pump in the discharge line valve is closed under the start, the vortex pump and axial pump in the valve fully open state to reduce starting power. ⑤ Centrifugal pump is suitable for direct drive with high-speed motor and steam turbine, simple structure, low manufacturing cost, easy maintenance. ⑥ wide range of application performance, centrifugal pump flow can be from a few to hundreds of thousands of meters 3 / hour, head can be from a few meters to several kilometers; axial flow pump generally suitable for large flow and low lift (20 meters below). Centrifugal pump and axial pump efficiency is generally below 80%, high up to 90%. ⑦ suitable for conveying very small viscosity of the cleaning liquid (such as water), specially designed pump can transport mud, sewage and other water or solid objects. Power pumps are mainly used for water supply, drainage, irrigation, process liquid delivery, power storage, hydraulic transmission and jet propulsion.