Use of CFD to Improve Control Valve Effectiveness

Control valves are used to adjust fluid flow rates in an extremely wide variety of applications. This paper discusses a steam flow control valve that is required to operate with a fairly wide range of inlet conditions (steam pressure) and provide effective control over a fairly wide range of steam flow rates. In this particular case a valve design was developed using “classical” methods — a combination of experience and hand calculations. The valve was tested and it did not provide adequate control over the flow for the application. The valve redesign effort used CFD to gain insight into the flow through the valve in order to evaluate control performance before the valve was fabricated and assembled. Several internal geometries were assessed and compared in order to identify two configurations that would meet the flow control requirements. These configurations were fabricated and tested and deemed to be adequate.