The pump is the equipment for transferring liquids or boosting liquids. The pumps transfer the mechanical energy or other external energy to the liquids, making the liquids increase their energy. The pump mainly transfer the water, oil, acid solution, alkali solution, emulsification solution, suspension solution, liquid metal and ect., And the pump can transfer liquid gas mixture and liquids with suspended solids. The main technical parameters of pumps include flow capacity, suction head, discharge head, shaft power, hydraulic power and efficiency. According to different working principle, the pump can be divided into volumetric pump and vane pump. The volumetric pump depends on the volume changes in its working cavity to transfer energy; the diaphragm pumps is belong to the volumetric pump; while the vane pump depends on interaction between the vane and liquids to transfer the energy. The centrifugal pumps, axial flow pumps and mixed-flow pumps are belong to vane pumps.