Modeling of impact of the poppet element on its seat body in pressure relief valves

This article deals with modeling of the impact between the moving elements and their seats bodies in pressure relief valves. Four different impact models, such as the Kelvin–Voigt, the Maxwell, the standard-solid and the Hunt–Crossley models, are considered. A comprehensive dynamic model of the studied valve, considering the four models, is deduced. The simulation results show that the Kelvin–Voigt model cannot be used to represent the impact in pressure relief valves because, by the end of impact period, the model results in a tensile force, which is physically impossible in rigid bodies impacting. In the Maxwell model, a considerable number of discontinuities appeared in the impact force, which causes the poppet element to make a number of rebounds with the seat body during the impact period. However, in the standard-solid model, the poppet element barely rebounds. In the Hunt–Crossley nonlinear model, a certain penetration distance between the poppet element and the seat body occurs, which is certainly unrealistic in rigid bodies impacting. The validation of the impact models showed that the Maxwell model is the suitable impact model that can be used to represent the impact in pressure relief valves. However, the validation of the proposed dynamic model proved that the impact has no significant effect on the dynamic performance of pressure relief valves. The main reason behind this is that the impact occurs when the operating pressure has fallen down (the valve is out of operation).