Patent attributes
A diaphragm actuator for a fluid process control device comprises a housing, a diaphragm, a stem, and a plate assembly. The plate assembly includes a concave plate and a convex plate, 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 of the stem and a nut threaded onto the stem. Accordingly, the concave plate forcibly engages and provides a fluid-tight 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.
