How does a back pressure regulator work?
A back pressure regulator works as a pressure-controlled relief valve on the inlet side of a system:
- Pressure rises above the setpoint. The regulator opens and vents the medium in a controlled way to return, drain or atmosphere.
- Pressure stabilises. As soon as the upstream pressure drops below the setpoint again, the regulator closes automatically.
- Continuous process. The system maintains a stable inlet pressure, regardless of variations in flow or load.
Difference from a forward pressure regulator: a forward regulator reduces the downstream pressure. A back pressure regulator protects and monitors the upstream inlet pressure. Both types are combined in the same system in more complex process architectures.
When do you need a back pressure regulator?
Back pressure regulators are the right choice if:
- your process must maintain a minimum inlet pressure for stable flow measurements or reactions;
- variable flows occur due to pump cycles, valve switching or gas changes;
- analytical instruments such as GC and MS only function correctly at a stable inlet pressure;
- pumps or compressors must be protected against back pressure fluctuations;
- you work with corrosive, high-purity or high-pressure media that require specialised materials;
- a maximum system pressure must be guaranteed without a safety valve.
Technical comparison per brand
| Kenmerk | GO Regulators | Parker Porter | Drastar | KOFLOC |
|---|
| Drukbereik | Up to 690 bar | 0 to 17 bar | 0 to 350 bar | 0 to 10 bar |
| Basisprincipe | Piston or spring | Direct-acting spring | Dome loaded or mechanical | Direct-acting spring |
| Materials | RVS 316, Brass | RVS 316, Brass | 316L, Hastelloy, Monel | RVS 316 |
| Leak tightness | Standard industrial | Low (analytical) | Ultra-low (He 10e9) | Low |
| Typical media | Inert gases, H2, CNG | Dry gas, N2, carrier gases | Corrosive gases, high purity | Clean gases, analysis gas |
| Application | Industry, test benches, gas distribution | GC/MS, OEM, labs | Semiconductor, R&D, specialty gas | Laboratorium, gasanalyse |
Specifications vary per model. Contact us for tailored advice.
GO Regulators for high pressure and industry
GO Regulators supplies back pressure regulators for applications where robustness, a wide pressure range and reliable operation at higher flows are paramount.
Features:
- Piston-operated design for fast response time and long service life
- Pressure ranges up to 690 bar, depending on model
- Suitable for inert and process gases, including H2 and CNG
- Wide selection of setpoint ranges and connections
Applications: industrial process installations, hydrogen and CNG stations, test benches, gas distribution, compressor outlets.
Parker Porter for analytical precision at low flow
Parker Porter BPRs are designed for analytical instrumentation and OEM applications where low hysteresis and high reproducibility are essential.
Features:
- Direct-acting design for stable control at low flows and small pressure differences
- Low internal volumes for fast system response
- Suitable for dry gases, nitrogen, air and carrier gases
- Widely applicable in OEM configurations
Applications: gas chromatography (GC/MS), analytical equipment, laboratory gas lines, OEM instrument building.
Drastar for high-purity and corrosive media
Drastar is the specialist for applications where leak tightness, material integrity and compatibility with aggressive media are an absolute priority.
Features:
- Ultra-low leak rate (He rates down to 10e9 for UHP versions)
- Material options: 316L stainless steel, Hastelloy C276, Monel 400
- Dome-loaded versions for stable control with varying flow
- Certified for semiconductor process environments
Applications: semiconductor production, specialty gas supply, corrosive process gases, high-end R&D installations.
KOFLOC for compact precision in clean service
KOFLOC BPRs combine a compact design with low dead volumes, making them particularly suitable for integrated instrument and analysis applications.
Features:
- Small internal volume for fast response and minimal contamination
- Easy integration into instrumentation systems
- Suitable for clean gases and analysis gas at low to medium pressure
- Compact size for space-saving installations
Applications: gas analysis systems, laboratory setups, measurement and control applications, inline integration.
Industrial process installations
In the process industry, back pressure regulators are used for reactor feed, gas distribution, compressor lines and venting systems. They protect downstream equipment against pressure peaks and ensure reproducible process conditions.
Hydrogen and CNG systems
In H2 and CNG installations, BPRs guarantee a safe maximum pressure in the system and protect tank outlets and distributors. GO Regulators are recognised as the standard for this segment.
Analytical laboratories and GC/MS
Gas chromatographs only work correctly with a stable and adjustable column pressure. Back pressure regulators on the carrier gas line or column outlet ensure repeatable analyses. Parker Porter is a leader in this segment.
Semiconductor and high-purity production
Process gas lines in chip production require components with proven leak tightness and inert material behaviour. Drastar BPRs with Hastelloy or Monel bodies meet the strictest SEMI standards.
Liquid systems and pump circuits
In dosing, mixing and high-pressure liquid systems, back pressure regulators prevent backflow, protect pumps and maintain a minimum system pressure for stable flow.
What is the difference between a back pressure regulator and a pressure relief valve?
A pressure relief valve only opens at overpressure as an emergency measure and is not designed for continuous control. A back pressure regulator is a precision instrument that continuously monitors and controls the upstream pressure, also under normal operating conditions.
Can I use a back pressure regulator for liquids?
Yes. Several models in our range, including GO and Drastar, are suitable for liquid applications. Pay attention to compatibility with the medium in terms of material, viscosity and vapours, and contact us for advice.
What is dome loaded and when do I choose it?
With a dome-loaded BPR, the setpoint is determined by a reference pressure on a diaphragm chamber instead of a mechanical spring. This offers more stable control with varying flow and higher accuracy. Drastar supplies dome-loaded versions for high-end applications.
Which BPR should I choose for corrosive gases?
For corrosive media such as HCl, Cl2, NF3 or HF, Inacom recommends Drastar BPRs in Hastelloy or Monel. These are specifically developed for high-purity and aggressive media.
Does Inacom also supply custom solutions or adapted connections?
Yes. For special pressure ranges, connections, material options or OEM integrations, we are happy to think along with you. Contact our technical department.
What are typical delivery times?
Standard models are usually available from stock or at short notice (2-4 weeks). Specify your application and we will give you a concrete delivery time.
Tailored advice from Inacom Instruments
Inacom Instruments has specialised in precision instrumentation for laboratories and the process industry for more than 35 years. Our technical specialists advise you based on your medium, pressure range, flow requirements and system architecture.
Contact us for technical advice or a quotation:
