Ultra Low Pressure Regulator for Very Low Flow | Equilibar

Ultra Low Pressure Regulator for Very Low Flow

Controls down to 0.01 psig - For air and inert gases at low and static flow

The unique Equilibar Ultra Low Pressure Regulator controls down to 0.3 in H20 / 1 mbar(g). Designed for static and very low flow applications, the patent pending LPR2 design extends the control range well below other commercially available regulators.

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The LPR2 is available in a “no-bleed” model (very low bleed) or with a bleed orifice, which provides for more stability and responsiveness when lowering the setpoint pressure. The standard (very low bleed) option is recommended for most bottled gas applications to minimize consumption.

Bleed Options:

Part # Option: Gas consumption
(@ 5 in H20)
Typical applications
LPR2-NB standard (very low bleed) <30 ml/min Bottled gases
(slow pressure reduction)
LPR2-B Bleed orifice Approximately 250 ml/min Instrument air
(rapid pressure reduction; maximum stability)

Outlet Ranges:

inH20 psig mbar(g)
0.3 – 7 0.01 – 0.25 0.75 – 17
1 – 10 0.04 – 0.36 2.5 – 25
1 – 28 0.04 to 1 2.5 – 70


Supply Pressure: 5 – 30 psig [0.34 – 2.0 bar(g)] (stable, regulated)
Ports: 1/4″ NPT inlet/outlet
Fluids: Air and inert gases
Major Materials: Cast zinc, Polyethylene, Rubber

Low Flow Test Results:

Sensitivity +/- 0.01 in H20 (0.0004 psig) [0.025 mbar(g)]
7 Day Stability +/- 0.06 in H20 (0.002 psig) [0.13 mbar(g)
Max Air Flow: Approx 3 lpm (6 SCFH) at 30 psig supply pressure
and 5 inH20 [12,5mbar] setpoint – see graph below
Gas Consumption: see bleed options above
Relieving Sensitivity: ~ 8 inH20 [20 mbar(g)] @ 1 SCFH [472 ml/min]
at setpoint of 2 inH20 [5 mbar(g)]

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LPR2 flow performance graph

Low Flow / No Flow Applications

The LPR2 can be used as a stand-alone pressure source for applications requiring no flow or very low gas flow:

  • Laboratory, research, scientific
  • Pressure testing delicate membranes

Medium/High Flow Applications
Use in combination with Equilibar Precision Back Pressure Regulator

The driving force behind the development of the LPR2 is as a setpoint pressure source for the Equilibar Precision Back Pressure Regulator. These back pressure regulators can mirror the ultra low pressure from the LPR2 into much larger process streams, providing pressure control capabilities never before experienced in chemical processes.

  • Vessel inert gas control
  • HVAC
  • Extrusion and blow molding cavity pressure control

Ultra Low Pressure Regulator

Other Low Pressure Solutions
Equilibar offers other precision solutions for the low pressure range including manual and electronic models.
Equilibar low pressure regulator series 41

Photo of Equilibar QPV Electronic Pressure Regulator

Contact Us for Information

Special Application Focus:
Precision Ultra Low Pressure Gas Supply System

There are very few if any commercial regulators capable of precisely controlling gas pressure below 0.5 psig / 34 millibar(g) with varying flow rates.

The LPR2 can be used in conjunction with an Equilibar precision back pressure regulator and a flow control valve to provide incredible precision and responsiveness. By venting any gas flow not required by the application, this system can accommodate forward or reverse gas flow at the application without loss of accuracy.

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