Back Pressure Regulators versus Pressure Reducing Regulators

Type Pressure Reducing
Regulator		 Back Pressure
Regulator
Schematic
Controls Pressure Downstream Upstream
Opens to: Increase pressure downstream Decrease pressure upstream
Closes to: Decrease pressure downstream Increase pressure upstream

Back pressure regulators work differently than standard, or pressure reducing regulators, and it is important to know the difference.

Pressure reducing regulators reduce a higher supply pressure at the inlet down to a regulated lower pressure at the outlet (downstream). Back pressure regualators work the opposite way. They regulate the higher inlet (upstream) pressure by opening up only as much as necessary to hold back the desired pressure at the inlet (upstream).

Back pressure regulators work just like relief valves, but the emphasis is on steady state pressure control instead of on/off pressure protection. Back pressure regulators are often used for:

  • control of pressure in recirculating loops
  • relief of excess system pressure
  • vacuum regulation

Can the Equilibar® be substituted for a standard regulator?

Some applications can be modified to accept back pressure regulator. Why would you do this? If you need extremely high precision in the low pressure range, or the convenience of accurately controlling a pressure from a remote computer signal, it may be worthwhile to determine if the Equilibar® back pressure regulator can still meet your needs.
  • Can you recirculate excess fluid back to an upstream vessel (i.e. a recirculating pump)?
  • Are you working with a low flow rate of air, water, or other fluid where an excess quantity can be economically exhausted or recycled?
lowpressureschematic (2K)

If the answer to either of these is yes or maybe, feel free to contact one of Equilibar's application engineers for a free consultation about your unique requirements. If we can't help you, we will recommend other products that will.

The schematic at right is an example of the Equilbar® being in place of a standard regulator to supply ultra-precise low-pressure flow control. The variable flowmeter supplies constant flow to the Equilibar®, which then exhausts only the portion not needed by the downstream process. For liquid or rare gas applications, the exhaust could be replaced by a recirculation pump to recover the excess flow.

The Equilibar® regulator is protected by granted and pending U.S. and foreign patents.
Copyright Equilibar, LLC 2007.