US Patent 9447890 Back pressure regulator with floating seal support

A sealing apparatus for a back pressure regulator includes: a body defining a process surface, and including: at least one process void communicating with the process surface; a recess disposed in the process surface; a floating support hub disposed in the recess, carrying an O-ring; a vent void communicating with the recess; an inlet port disposed in fluid communication with the at least one process void and adapted to be coupled in fluid communication with a fluid at a process pressure; and an outlet port disposed in fluid communication with the vent void; and a diaphragm having opposed reference and process sides, the diaphragm disposed against the body such that the process side is substantially coplanar with the process surface.