And water as the high-speed centrifugal impeller rotation, the water under the action of centrifugal force, thrown to the outer periphery of the impeller, volute pump casing through the flow passage flows into the water conduit of the pump pressure. The center of the pump impeller, the centrifugal force due to water forms a vacuum after being thrown, the pool of water absorption under pressure in the atmosphere will be pressed into the pump casing, the impeller is rotated by the stop, so that the water in the impeller the role of the continuous inflow and outflow, achieve the purpose of conveying water.