Pressure Regulator for Fuel Cells | Equilibar

Fuel Cell Pressure Regulator

Back Pressure Regulators for Fuel Cell Testing

  • fuel cell testing schematic with Equilibar back pressure regulators

Key performance characteristics for fuel cell pressure control

The Equilibar® precision back pressure regulator (BPR) is the perfect fit for pressure control in fuel cell testing systems. In particular, fuel cell test stands benefit from

  • The high sensitivity of the Equilibar BPR in the low to mid pressure ranges that is lacking in most competitive products.
  • The unmatched 1000:1 flow turn-down ratio and control range of the Equilibar BPR
  • The capacity of the Equilibar BPR to control multiphase fluids with extreme precision due to its unique multi orifice design.
  • The dome-loaded control of the Equilibar BPR allowing it to pair with an electronic controller for superior automation.

Low Flow Control
Incredible 1000:1 Flow Rate Turn-down Ratio

Equilibar’s “GR” trim was specifically designed in response to the demanding flow rate requirements of the fuel cell testing industry. These GR trim regulators can provide stable stack pressures through ultra wide flow rate ranges required for rigorous test protocols. Gas flow rate control is possible down to below 1 ml/minute.

fuel cell testing schematic with Equilibar back pressure regulators

Equilibar BPRs control pressure on the outlet of the anode and cathode

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Ease of Computer Automation

The Equilibar BPR operates using a pilot regulator on its dome to provide a setpoint. The dome loaded design is sensitive to changes in an Electro-Pneumatic Regulator (EPR) setpoint as small as 0.001 psig, giving a process computer unprecedented control of gas system pressures. While most fuel cell testing systems use closed-loop PID feedback on the stack outlet pressure sensor, the incredible precision of the Equilibar BPR allows for full system control using an EPR with open-loop control or simply using a manual pressure regulator as a pilot setpoint regulator.

Ability to Control Multi-phase Fluids

The unique multi-orifice design of Equilibar BPR allows for stable pressure control across a wide Cv range and can easily handle mixed phase (liquid-gas) flow or varying pressures on the outlet of the BPR. Multi-phase flow in fuel cell testing systems occurs when gas and condensation are mixed. Traditional valves and back pressure regulators may have a single annular valve seat, often very small. Slugs of liquid and gas mixture in the small throat of these valves may cause a disruption in the stability of the upstream process pressure. The Equilibar BPR with it multiple orifices handles the liquid/gas mixture smoothly.

Contact one of our Applications Engineers to help select the perfect back pressure regulator for your fuel cell application.

GS Series Equilibar Back Pressure Regulator

The Fuel Cell and Hydrogen Energy Association is dedicated to the commercialization of fuel cells and hydrogen energy technologies.

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BD back pressure regulator with triclamp elbows

Equilibar BD back pressure regulator with triclamp elbows


GSD4 General Service Back Pressure RegulatorThe Equilibar® GS Series is a high performance back pressure regulator ideally suited for Fuel Cell Testing applications.

The Equilibar® BD Series with electronic pilot regulator for computer automation. BD valves are larger high performance back pressure regulators used in Fuel Cell Testing applications.

Customer Case Study – Improving catalysts for automotive fuel cells

Researchers at Charles University in Prague, Czech Republic, have successfully used an Equilibar® Back Pressure Regulator combined with a QPV electronic pressure regulator to provide precise control of fuel cell anode and cathode pressure across a wide range of test conditions. The research is part of vital international efforts to develop improved environmental catalysts for automotive fuel cells. At Charles University, fuel cell research is working to develop improved catalysts with the goal of lowering noble metal content, which would directly lower the cost of the power supply while also using more environmentally friendly materials. Read a detailed account in the link to the right.

Fuel cell test stand cooling loop

Cooling loops are an important part of any fuel cell test stand, as the temperature of the gas entering the cell must be tightly controlled. While Equilibar BPRs are most commonly used for direct cell/stack pressure control, they may also be used in lieu of traditional control valves in the liquid cooling loop as well. The wide Cv range of the Equilibar allows for stable control of the pressure or flow in the cooling loop across a wide operating range that may take several traditional control valves to cover. Additionally, the simple design of the Equilibar allows for easy maintenance, with most valves being able to be fully rebuilt in the field within a matter of minutes. The multi-orifice design of our valves also prevents cavitation damage that is a common concern for single seat valves in high dP liquid systems.


Fuel Cell Testing case study from Charles University in Prague

schematic of cooling loop process temperature control

Liquid cooling loop controlled by an Equilibar BPR

BD back pressure valve is often used fuel cell testing application with higher flow ranges.

image of Equilibar BD16 back pressure valve

BD16 Industrial Back Pressure Regulator

Port Sizes:
Typical Pressure Ranges:
0 - 1 in WC
0 - 28 in WC
0 - 5 psi
0 - 10 psi
0 - 20 psi
0 - 30 psi
0 - 60 psi
Key Applications:
Technical Details

An Equilibar GS series regulator is a good solution for your lower flow range fuel cell testing

GSD4 General Service Back Pressure Regulator

GSD4 General Service Back Pressure Regulator

Port Sizes:
Typical Pressure Ranges:
0 - 1 in WC
0 - 10 in WC
0 - 2 psi
0 - 5 psi
0 - 10 psi
0 - 20 psi
0 - 30 psi
0 - 60 psi
0 - 100 psi
0 - 150 psi
0 - 200 psi
0 - 250 psi
0 - 300 psi
Key Applications:
Technical Details

Watch the video below of how the Equilibar Back Pressure Regulator works.

How Equilibar Back Pressure Regulator Works

Work Categories
Equilibar News
David Reed and Julie Detmering with undersecretary of commerce and e star award

Equilibar receives national recognition for growth & expertise in exports

At a May 14 ceremony in Washington, DC, the U.S. Department of Commerce honored Equilibar with the 2024 President’s “E Star” Award in recognition of the company’s continuing notable contributions to an increase in U.S. exports. The “E Star” Award recognizes at least four years of additional export growth by American companies that previously received Read More

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