| 摘要 |
A sanitary diaphragm valve is provided that includes a generally dome shaped diaphragm having a central boss that can be connected to or driven by a valve actuator. The diaphragm includes an outer peripheral edge and a relatively thin web portion that connects the boss to the outer edge. In one embodiment, the web portion is arcuate or dome shaped. The thinner web portion permits the diaphragm to have an extended cycle life and to permit the valve to operate at higher fluid pressures. The thin web may be defined by two different contoured surfaces, one convex and the other concave, such as formed by two radiuses. A valve body is provided that includes a bowl shaped valve cavity. This valve cavity includes an outer vertical edge to permit more thorough cleaning and to eliminate entrapment areas. The valve assembly provides support surfaces for the diaphragm that reduces stress on the diaphragm particularly at higher operating pressures. A deep bowl embodiment is provided in which the valve cavity is defined by a spherical and preferably a hemispherical surface with the cavity diameter being about the same as the diaphragm diameter. The diaphragm for the deep bowl design has a stem tip that seals one of the valve ports radially outward from the port. The port may include a chamfered valve seat adjacent the port, and the port may be formed by a conical bore.
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