Pressure reducing valves
Precise pressure control for steam, industrial water and compressed air systems. Pressure reducers maintain constant, stable downstream pressure, optimising energy efficiency and protecting downstream equipment.
Why use a pressure reducing valve
Boilers generate high-pressure steam for efficiency reasons, but many items of equipment require lower pressures. Pressure reducing valves solve this problem, providing steam at the exact pressure required by each process — whether heating, sterilisation, humidification or otherwise.
The same principle applies to industrial water (mains pressure too high for some uses) and compressed air (compressors operating at pressures higher than needed at point of use).
Roffia distributes Spirax Sarco pressure reducers for steam — world leader in the sector — and Caleffi for water and heating. Our technical team can assist with selection and sizing.
Benefits of pressure control
Lower pressure steam = more latent heat per kg
Equipment protected from overpressure
More stable, controlled process
Less stress on valves and components
Types of pressure reducers
Pilot-operated steam reducers
Pilot-operated reducers use a separate pilot to control the main valve opening. They offer excellent regulation accuracy (±0.1 bar) and are ideal for high and variable flow rates. Downstream pressure remains stable even with large load variations.
Technical specifications
- Inlet pressure: up to 25 bar
- Outlet pressure: 0.2 - 17 bar (adjustable)
- Temperature: up to 250°C (saturated steam)
- Connections: flanged DN 15-150
- Accuracy: ±0.1 bar / ±2%
Reference model: Spirax Sarco 25 series
Applications: main steam lines, pressure reducing stations, critical process supply, high flow rates.
Direct-acting diaphragm steam reducers
Direct-acting diaphragm reducers are more compact and simpler than pilot-operated types. A flexible diaphragm balances downstream pressure against an adjustable spring. Ideal for small-medium flows and where simplicity is the priority.
Technical specifications
- Inlet pressure: up to 17 bar
- Outlet pressure: 0.1 - 10 bar (adjustable)
- Temperature: up to 200°C
- Connections: threaded DN 15-50, flanged DN 15-80
- Accuracy: ±0.2 bar / ±5%
Reference models: Spirax Sarco DP, DRV series
Applications: individual equipment, steam tracing, small processes, heating.
Water pressure reducers
Water pressure reducers reduce mains pressure (typically 4-8 bar) to lower values to protect taps, appliances and systems. Versions are available for drinking water (food-contact certified) and industrial water.
Technical specifications
- Inlet pressure: up to 25 bar
- Outlet pressure: 0.5 - 6 bar (adjustable)
- Temperature: up to 80°C (hot water)
- Connections: threaded DN 15-50, flanged DN 50-150
- Materials: brass, bronze, cast iron, stainless steel
Brands: Caleffi, Socla
Applications: building inlets, boiler protection, water systems, irrigation, food industry.
Compressed air and gas reducers
Reducers for compressed air and technical gases reduce pressure from the main line to the values required by end uses (pneumatic tools, instrumentation, control). Also available for special gases (nitrogen, CO₂, argon).
Technical specifications
- Inlet pressure: up to 40 bar
- Outlet pressure: 0.5 - 16 bar (adjustable)
- Temperature: -20°C to +60°C
- Connections: threaded DN 8-50
- Materials: aluminium, brass, steel, stainless
Applications: compressed air lines, pneumatic tools, instrumentation, technical gases, automation.
Pressure reducer selection guide
| Application | Reducer type | Recommended brand | Notes |
|---|---|---|---|
| Main steam line | Pilot-operated | Spirax Sarco 25 | High accuracy, large flows |
| Single steam equipment | Diaphragm | Spirax Sarco DP | Compact, economical |
| Reduction >10:1 | Two in series | Spirax Sarco | Avoids thermal shock |
| Drinking water | Diaphragm | Caleffi | Food-contact certified |
| Compressed air | Direct/Pilot | Various | Select by flow rate |
| Technical gases | Gas-specific | On request | Material compatibility |
Installation and recommended accessories
Upstream strainer
Always install a Y-strainer upstream of the reducer to protect the seat from debris. Recommended mesh: 0.5-1 mm for steam, 0.8-1.5 mm for water.
Isolation valves
Provide isolation valves upstream and downstream to permit maintenance without draining the entire circuit.
Pressure gauges
Install pressure gauges upstream and downstream to monitor correct operation and verify reduced pressure.
Domande frequenti
What is the difference between a pressure reducing valve and a pressure regulator?
How do you size a steam pressure reducing valve?
Why use a pressure reducing valve for steam?
What pressure reducer brands does Roffia distribute?
How often should a pressure reducing valve be checked?
Is a strainer needed upstream of the pressure reducing valve?
Need pressure reducing valves?
Contact us with your application specs: fluid, inlet/outlet pressure, flow rate, temperature. We'll recommend the most suitable solution for your system.