Study of Hydrodynamic Torque of Double Offset Butterfly Valve Disc through Experiment and CFD Analysis

Abstract

A butterfly valve is commonly used as control device in applications where the inlet velocity is high and the pressure drop required is relatively low. Hydrodynamic torque is a significant design parameter for engineers dealing with control valve design. Predicting the hydrodynamic torque for all opening and closing conditions in rotary valves is of utmost importance. This study sought to compare experimental and simulated computational fluid dynamics (CFD) performance factor and hydrodynamic torque of 150mm double offset butterfly disc for various opening and closing angles in the increments of 100. In general, as the flow rate increases through the valve, greater force is exerted upon the disc by the fluid. These increased dynamic forces require more torque to rotate the disc. The amount of torque required to rotate the disc during operation varies depending on type of fluid flowing through the valve, velocity, shape and position of the disc. Finally a correlation has been established between the experiment and CFD values and valve industry can make use of this data for optimum selection of gear box and actuator.