How the Equilibar Back Pressure Regulator Works
The Equilibar® Back Pressure Regulator is unique type of dome-loaded back pressure regulator. It works like a fluid transistor by forming a unique force balance on an flexible membrane between three separate pressures.
The fluid inlet pressure and the downstream vent pressure exist on the wetted side of the membrane, separated by valve seats. The reference air pressure exists on the non-wetted side of the membrane.
The lower pressure of the exhaust tries to hold the membrane in a leak-tight seal with the valve seat. However, any slight excess between the fluid inlet pressure and the reference pressure quickly overwhelms these seating forces and pushes the membrane away from the valve seat.
Traditional backpressure regulators use springs to gradually open up as the overpressure is used to compress the spring. The Equilibar® pressure regulator uses only a frictionless flexible membrane to modulate the pressure. It fully opens in less than 1% overpressure; less than 0.01 psi in some applications.
Varying performance curves can be generated by altering valve geometry, which in turns affects the complex 3-dimensional shape of the membrane in the vicinity of the valve seat.
