Structural Optimization of a Water Hydraulic Pilot-Operated Pressure-Reducing Valve

The characteristics of a pilot-operated pressure-reducing valve for water hydraulics are analysed. The valve operates well with a primary pressure of up to 15MPa, a secondary pressure range of 10MPa to 14MPa, and a flow range of 20L/min to 40L/min. Optimizations are applied to reduce the cavitation noise of the valve and to improve the pressure regulation accuracy of secondary pressure. The first optimization is executed by reducing pressure drop and velocity through the throttle of main spool and the second optimization is carried out by lowering down the steady jet force on both main spool and the pilot spool. The dynamic characteristics of the secondary pressure are obtained by simulations. The results show the valve behaviours better with the improvement structure. The average variation of the secondary pressure is brought down from 0.308MPa to 0.175MPa under different primary pressure conditions and from 0.288MPa to 0.136MPa under different inlet flowrate conditions. The velocity through throttle of the main spool is 31.18% cut down on average.