Structural design and parameter optimization on a waste valve for hydraulic ram pumps

Hydraulic ram pump is an automatic water-lifting machinery, which converts the low-head potential energy of a large volume of water into a small high-head potential energy through the periodic open and close of waste valve and delivery valve. The pump would run inefficiently or even fail if the valves are poorly designed. In this paper, a novel and reliable waste valve of lift-check-valve structure has been developed. The sealing mode integrating soft and rigid sealing rings, the equation for the valve disc thickness and the equation for the flow passage in terms of the diffuser length, the larger radius and the smaller radius, are presented to guide future design. Major factors influencing the hydraulic performance, including the flow passage, valve opening and valve clack mass, are discussed with model experiments and numerical simulations. The optimized configuration for a 100-mm hydraulic ram pump includes a curved diffuser, 25-30-mm valve opening and 1.2-kg valve clack mass. The proposed waste valve can decrease the head loss coefficient of the system by 45%, achieve relatively higher working efficiency, and lift the largest water when the delivery head is lower than 30 m.