Quality improvement of a safety valve with the use of numerical and experimental studies

This article presents results of numerical modelling, simulation and test bench experiments of a hydraulic direct-acting relief valve was used as a safety valve. The analyzed safety valve was placed in a system consisting of a fixed-speed pump, a control valve, a hydraulic cylinder as an actuator and a second pressure valve in the load line used as a payload generator for the cylinder. In the first step mathematical model of the system was formulated in the form of a system of ordinary differential equations. Next, simulation model was created in Matlab/Simulink. Simulations were carried out for different values of the actuator payload. The obtained results include time series of pressure, flow rate and displacement of the actuator piston. In order to confirm simulation results, a test bench was built and series of experiments were carried out. High compliance of simulation and laboratory results was obtained. It was confirmed that the proposed solution with the relief valve used as a safety valve fulfills its task of protecting the hydraulic system from excessive pressure increase.