Dynamic simulation of a pressure regulating and shut-off valve

•Dynamic simulation of PRSOV valve.•Spool position adjusted after force balance.•Final position of spool predicted.

Dynamic modeling of flow process inside a pressure regulating and shut-off valve has been investigated using a computational fluid dynamic approach. The valve is designed to reduce high inlet pressure to a lower level of outlet pressure which remains almost constant. With the change of inlet pressure, the change in position of the spool inside the valve was calculated using a force balance approach. The Navier–Stokes equation along with appropriate turbulent closure has been solved for this purpose in the compressible flow regime using ANSYS-FLUENT software with special functions developed for calculation of flow force. The code could predict the spool movement and the final spool position when the spool position is deviated from equilibrium. The final spool position and time required to reach equilibrium, besides the flow parameters, also depends on the value of friction coefficient between spool and the valve-body. Higher values of friction coefficient between the spool and the vale body is found to be associated with faster stability of the spool.