Abstract: The simulation and experiments on pilot-operated water hydraulic relief valve are carried out in our lab. The structure of the main valve port is characterized with high-pressure induct and two-step restrictor. The AMESim model of the valve is built. The influence parameters, such as guide clearance of pilot valve, diameter of damping orifice, volume of sensitive cavity, mass of valve core, and spring stiffness, are investigated through simulation. The static and dynamic experiments are carried out on the water hydraulic comprehensive test-rig to test the valve performance. The simulation and test results are compared and analyzed，which shows that the effect of spool mass can be neglected, but the diameter of damping orifice has great effect. The setting-pressure accuracy is low at small flow rate below 20 L/min, but the high accuracy is achieved over 20 L/min. The experiments about valve dynamic response show that the overshoot of inlet pressure is no more than 30% and the pressure rise time is less than 80 ms.

Key words: Influence parameter, Pilot-operated water hydraulic relief valve, Static and dynamic experiments, Static and dynamic simulation