Weir Type

Overview

The weir/saddle type diaphragm valve is the most common diaphragm valve design [1]. Its design uses a raised lip on the pipe body that comes into contact with the diaphragm. Therefore, the diaphragm in a weir type valve is generally smaller and does not need to be as flexible as other types due to its relatively shorter distance of travel, reducing the amount of stress put upon the diaphragm. Another benefit of the weir type is safety. The bonnet of a weir type valve is usually designed to enclose any leakage of material in the event of a diaphragm failure, making the weir type diaphragm valve suitable for applications involving corrosive, dangerous chemicals [2].

However, due to their design, weir type diaphragm valves are susceptible to viscous fluids, slurries, and/or sediments collecting around the weir structure, making the weir type diaphragm valve more suitable for homogenous and clean fluids [3]. Another similar problem with this design could inhibit fully draining the system depending on the application.