Pressure drop analysis for hydraulic valves

Abstract

Abstract The Directional Control Valves are one of the important components in the field of hydraulics. Directional Control Valves channelize the oil to the required path so that the required operations are performed. If the valve has to perform well, the design should be such that the pressure drop across the valve should be minimum. At present the valves which are available in the market are working satisfactorily, the pressure drop across them vary based on the design and the number of stations used. Pressure drop will be more in valves of complicated designs. The main objective is to find the pressure drop in the valve across different stations of directional control valve for different flow rates. Computational Fluid Dynamics (CFD) analysis is carried out on the oil flow path of the valve using FEA software (ANSYS FLUENT). CFD analysis was done by selecting the fluid properties of oil. Pressure drop was obtained on all the three positions of the valve along the oil flow path. Maximum deformation and stresses were determined. The experimental, theoretical and ANSYS results were obtained. For flow rate of 20 lpm in P-T direction, pressure drop was 0.19 bar experimentally, 0.57 bar theoretically, and 1.61 bar in ANSYS. It was found that pressure drop was within the limit of 0 to 40 bar. It was found that pressure drop is directly proportional to flow rate and viscosity, and flow rate and viscosity are dependent on each other. Therefore it is clear that pressure drop plays a very important role in working of the valve. Only experimental and ANSYS methods were available but no theoretical method was available. Here the theoretical method was obtained and was compared with experimental and ANSYS.