RING SEALED DIAPHRAGM

摘要

A diaphragm actuator (10) for a fluid process control device comprises a housing (26), a diaphragm (56), a stem (22), and a plate assembly. The plate assembly includes a concave plate (54) and a convex plate (52), each having inner and outer radial portions. The outer radial portions compressingly engage and retain the diaphragm. The inner radial portions are compressed together onto the stem between a shoulder (72) of the stem and a nut (48) threaded onto the stem. Accordingly, the concave plate forcibly engages and provides a fluidtight seal directly with the shoulder of the stem without requiring an o-ring or any other additional sealing component. Moreover, the concave and convex plates are structurally equivalent such that the actuator may easily be switched between a biased-open configuration and a biased-closed configuration.