Abstract: The mathematical model for a novel two-stage water hydraulic relief valve is estabilished. Numerical simulation on its dynamic characteristics is analysed. Simulation results clarify that setting damping chamber at the pilot stage is benefit to improve the pilot valve’s stability. The main valve’s differential working pressure can be decreased greatly by adding a suitable throttle for the purpose of reducing cavitation, enhancing the valve’s performance and service life. The results also show that the upper chamber volume V12 of the main valve, the inlet chamber volume V2 of the pilot valve and the inlet chamber volume V0 of the relief valve influence the relief valve’s dy-namic characteristics markedly.

Key words: Dynamic characteristics, Mathematical model, Numerical simulation, Two-stage water hydraulic relief valve, Deformation, Microstructure, Phase transformation, Boron steel, Hot stamping