Back-Pressure Regulators
Back pressure regulators (BPRs) are pressure-control devices installed at the outlet of a flow chemistry system — or at defined points within the flow train — to maintain a set operating pressure throughout the upstream reactor and process equipment regardless of flow rate variation or downstream pressure changes. BPRs are not merely safety relief valves: they are precision pressure-control instruments that actively regulate the upstream system pressure to a setpoint, enabling flow chemistry to be conducted at pressures well above the atmospheric boiling point of the process solvent — a critical capability that unlocks a large chemical space otherwise inaccessible in atmospheric-pressure batch or flow equipment. Operating above the solvent boiling point under BPR-controlled pressure is one of the most exploited advantages of flow chemistry: reactions in ethanol at 150°C, water at 200°C, or DCM at 100°C become routine when the system pressure is elevated to 5–15 bar above the solvent vapour pressure. The BPR maintains this pressure at the reactor outlet, while a back-pressure-rated pump delivers the reagent stream at a delivery pressure higher than the setpoint — the net flow through the BPR is determined by the difference between the pump delivery pressure and the BPR setpoint.
BPR designs used in flow chemistry include: spring-loaded disc valves (simple, reliable, but fixed setpoint per spring), pneumatically actuated dome-loaded BPRs (variable setpoint 0–350 bar set by nitrogen reference pressure — the most versatile and widely used), and electronically actuated needle valve BPRs (motor-driven valve with setpoint programmed digitally — enables pressure ramping and programming within the flow chemistry control software). For gas–liquid flow systems (e.g., H₂/organic in hydrogenation), the BPR must handle two-phase flow without sticking or cavitation — specialised gas–liquid BPR designs use enlarged orifice areas and corrosion-resistant seats to ensure reliable operation. Wetted materials are specified for process chemistry compatibility: PEEK, PTFE, and Hastelloy C-276 for acidic, basic, or halogenated streams.
- BPR Types Spring-loaded disc, dome-loaded (N₂ reference…
- Pressure Range 0.5 bar to 350 bar (design dependent)
- Setpoint Accuracy ±0.05 bar (dome-loaded); ±0.1 bar (spring-loa…
- Flow Rate Range 0.1 mL/min to 5 L/min (lab–pilot scale)
- Wetted Materials PEEK, PTFE, Hastelloy C-276, SS 316L, gold-pl…
- Process Media Single-phase liquid, gas–liquid (two-phase), …
Key Features
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Enables reactions above solvent boiling point — superheated flow chemistry
Enables reactions above solvent boiling point — superheated flow chemistry
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Dome-loaded designs allow variable setpoint 0–350 bar in real time
Dome-loaded designs allow variable setpoint 0–350 bar in real time
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Electronic BPRs support pressure ramping for reaction optimisation
Electronic BPRs support pressure ramping for reaction optimisation
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Two-phase BPR designs handle gas–liquid streams without sticking
Two-phase BPR designs handle gas–liquid streams without sticking
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PEEK and Hastelloy wetted parts for full chemical compatibility
PEEK and Hastelloy wetted parts for full chemical compatibility
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Maintains constant upstream pressure independent of flow rate change
Maintains constant upstream pressure independent of flow rate change
System Components
Modular assemblies engineered for reliable integration, service access, and scale-up from laboratory to pilot plant operation.
Applications
- Maintaining system pressure for high-temperature superheated reactions
- Back-pressure on hydrogenation reactors to maintain H₂ in solution
- Pressure control on tubular reactors with dissolved gas feed streams
- Supercritical
- CO₂ (sc
- CO₂) reaction system pressure management
- Biphasic gas–liquid system outlet pressure regulation
- Preventing cavitation in high-temperature pump delivery lines
Technical Specifications
| Parameter | Specification |
|---|---|
| BPR Types | Spring-loaded disc, dome-loaded (N₂ reference), electronic needle valve |
| Pressure Range | 0.5 bar to 350 bar (design dependent) |
| Setpoint Accuracy | ±0.05 bar (dome-loaded); ±0.1 bar (spring-loaded) |
| Flow Rate Range | 0.1 mL/min to 5 L/min (lab–pilot scale) |
| Wetted Materials | PEEK, PTFE, Hastelloy C-276, SS 316L, gold-plated seats |
| Process Media | Single-phase liquid, gas–liquid (two-phase), supercritical CO₂ |
| Temperature Range | −20°C to +200°C (standard); up to +300°C (high-T designs) |
| Control Interface | Manual (dome), analogue 4–20 mA (electronic), digital Modbus |
| Certifications | CE/PED compliant; ATEX variants available |
| Special Types | Two-phase gas–liquid BPR; scCO₂-rated BPR; high-T BPR |
| Performance Advantage | A dome-loaded BPR set at 10 bar enables continuous reactions in water at 180°C — a superheated regime that accelerates hydrolysis, esterification, and hydrothermal reactions by 50–200× relative to atmospheric reflux — with immediate pressure release at end of campaign. |
Related Products
FAQ
What capacity range is available for Back Pressure Regulators?
We offer project-specific sizing from laboratory benchtop scale through pilot and production volumes. Contact our engineers with your batch size and process requirements for a tailored recommendation.
Can this unit be integrated with existing plant automation?
Yes. All systems support standard instrumentation signals and can interface with DCS, PLC, or standalone controllers. Custom I/O and recipe control packages are available.
What material options are available?
Borosilicate glass, glass-lined steel, stainless steel, and specialty alloys including Hastelloy can be specified based on your process chemistry, temperature, and pressure requirements.
Do you provide installation and commissioning?
Global Lindus provides on-site installation supervision, commissioning, operator training, and optional IQ/OQ documentation for regulated industries.
What is the typical delivery lead time?
Standard configurations ship in 4–8 weeks. Custom skid assemblies and large production units may require 12–16 weeks depending on scope and material availability.