Diaphragm Valve Hydraulic Behavior Depending on Operating Pressure

In this study, a hydraulically operated and diaphragm-actuated type of diaphragm valve using an elastic diaphragm was tested. With this type of valve, the opening fraction depends on the pipeline pressure; thus, it is important to determine the minimum operating pressure. The outlet pressure was determined to be the critical pressure ensuring the full opening. The valve flow coefficient was found to be a good indicator of the valve opening fraction. A test procedure was presented to determine the minimum outlet pressure. The pressure had to be continuously increased during testing to avoid hysteresis. An unsteady valve behavior was observed after a sudden intense pressure decrease.