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Pump is a mechanical energy through mechanical energy will fluid energy (kinetic or potential energy) to enhance the mechanical device, the use of impeller rotation, piston reciprocation and other principles to change the pump volume or produce centrifugal force, drive the fluid flow, to achieve the transmission, pressurization or circulation function. According to the working principle can be divided into volumetric pumps (such as piston pumps) and vane pumps (such as centrifugal pumps) and other types.