Back pressure regulator with floating seal support

A back pressure regulator apparatus comprising:

• 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, wherein a height of the hub measured between upper and lower ends thereof is less than a cross-sectional diameter of the O-ring, and wherein a gap is present between the hub and the process surface;
• 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;
• a reference cap including a reference surface and a reference port disposed in fluid communication with the reference surface, the reference port adapted to be coupled in fluid communication with a fluid at a predetermined reference pressure;
• and
• a diaphragm having opposed reference and process sides, the diaphragm constrained between the body and the reference cap such that the process side is substantially coplanar with the process surface, and arranged such that, in response to the process pressure being higher than the reference pressure, a fluid flow path will be open that extends from the at least one process void past the O-ring to the vent void, and in response to the reference pressure being higher than the process pressure, the flow path will be closed.

A back pressure regulator apparatus comprising:

• 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, wherein a height of the hub measured between upper and lower ends thereof is less than a cross-sectional diameter of the O-ring, and wherein a gap is present between the hub and the process surface;
• 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;
• a reference cap including a reference surface;
• a diaphragm having opposed reference and process sides, the diaphragm constrained between the body and the reference cap such that the process side is substantially coplanar with the process surface;
• and
• a platen loaded by a spring disposed within the reference cap such that the platen applies a reference force to the diaphragm,
• wherein the diaphragm is arranged such that, in response to forces exerted on the diaphragm by the process pressure being higher than the reference force, a fluid flow path will be open that extends from the at least one process void past the O-ring to the vent void, and in response to the reference force being higher than the forces exerted on the diaphragm by the process pressure, the flow path will be closed.