A sanitary diaphragm valve is provided that includes a generally dome shaped diaphragm (E) having a central boss (12) that can be connected to or driven by a valve actuator (C). The diaphragm (E) includes an outer peripheral edge (14) and a relatively thin web (16) portion that connects the boss (12) to the outer edge (14). In one embodiment, the web (16) portion is arcuate or dome shaped. The thinner web (16) portion permits the diaphragm (E) to have an extended cycle life and to permit the valve to operate at higher fluid pressures. The diaphragm (E) may be made from a chemically resistant material and optimized to maintain high flexure.
