Centrifugal pump and axial flow pump water absorption function is based on the vacuum formed by the suction port, so that water under atmospheric pressure, was inhaled impeller center. In theory, it can draw no less than 10m of water in the pump center. In fact, the pumping height of a typical water pump is only 5-7m. Mostly for deep-well pump axial pump, suction stroke even lower. Only its pump body and impeller are immersed in water downhole. Pump on the well tube leading to the ground. After the water is gradually boosted by the impeller of the pump, it is discharged to the ground by the well tube. It is able to send deep groundwater not because of its strong suction ability, but when the water is pressurized underneath and under pressure Send it up The deeper the groundwater level, the higher the pressure head required to send water up and the deeper the pump will be.