Water hummer pump can effectively use the water hammer phenomenon that include pumps and allow fluid transport without drive sources such as electric motors. The results of experiments that examined the effect of the geometric form of eater hammer pumps by considering their major dimensions have been reported. However, these conventional studies have not fully evaluated the pump performance in terms of pump head and flow rate, common measures indicating the performance of pumps. The previous paper experimentally examined how the hydrodynamic characteristics ware affected by the inner diameter ratio of the drive and lifting pipes, the form of air chamber, and the angle of the drive pipe. This paper experimentally examines how the water hammer pump performance is affected by number of spring in drain valve. It also clarifies the behavior of flow in the valve chamber during water hammer pump operation.
