three-way force balance
The Equilibar controls inlet pressure through three-way force balance where the diaphragm touches the outlet orifice

How the Equilibar back pressure regulator works
Equilibar's unique performance advantages comes from its supple diaphragm and the multiple orifice design. The pilot set-point pressure can be supplied by either a manual or electronic pressure regulator

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 diaphragm, separated by orifices. The pilot set-point pressure is on the non-wetted side of the diaphragm.;

The lower pressure at the outlet tries to hold the diaphragm in a leak-tight seal with the orifice.  However, any slight excess between the fluid inlet pressure and the pilot set-point pressure quickly overwhelms these seating forces and lifts the diaphragm off of the orifices. The result is a lightning-fast response, keeping the inlet pressure in tight equilibrium with the set-point pressure.

Traditional backpressure regulators use springs to gradually open up as the overpressure is used to compress the spring. This change in the spring constant as the spring is compressed is a major source of error, or overpressure, in traditional designs. The unique multi-orifice design also gives Equilibar its ultra-wide flow range, typically 100X wider flow range than traditional back pressure regulators.

precision performance fromEquilibar back pressure regulator

The Equilibar back pressure regulator provides unmatched stability through flow rate ranges as wide as 1000:1 and 10,000:1.