Pressure reducing valves (PRVs) hold a steady downstream pressure regardless of changes in upstream pressure or demand. JBM builds complete PRV stations from 15 to 150 NB around bought-out valves from approved makes, covering direct-acting, pilot-operated, air-loaded, electro-pneumatic, and self-acting designs for plant steam, clean steam, air, gas, and water, with single-stage reduction up to 10:1.
The valve senses downstream pressure on a diaphragm and balances it against a spring or pilot setting, opening when pressure falls and closing when it rises. Pilot-operated valves use a small pilot to control the main valve for tighter accuracy over wide loads. A complete station adds a separator, strainer, isolation valves, bypass, pressure gauges, and a downstream safety valve, with outlet piping enlarged to hold steam velocity near 25 m/s.
Challenges
Wet Steam Erosion
Water droplets wire-draw valve seats at high pressure drop.
Pressure Droop
Direct-acting valves lose set pressure as load increases.
Noise and Vibration
High reduction ratios and velocities create noise above 85 dBA.
Low-Load Hunting
Oversized valves cycle and wear at low demand.
Overpressure Risk
Valve failure can expose downstream equipment to full supply pressure.
Solutions
- Separator + Strainer Upstream: Dry, clean steam protects the seat and pilot.
- Pilot-Operated Control: Holds set pressure within ±1% across the load range.
- Two-Stage Reduction + Expanded Outlet: Splits large drops and limits outlet velocity to 25 m/s.
- Parallel Valve Stations: Small and large valves in parallel cover wide turndown.
- Downstream Safety Valve: Sized for full PRV capacity to protect users.
Applications
- Pharmaceutical: Reactor jackets, autoclaves, and clean steam users.
- Food & Beverage: Cookers, CIP heaters, and low-pressure process steam.
- Chemical: Reboilers, heat exchangers, and tracing supply.
- Utilities: Compressed air, nitrogen, and water pressure control.
Types & Configurations
| Type | Code | Design & Operation | Size [NB] | Accuracy | Typical Use | Supply |
|---|---|---|---|---|---|---|
| By Operation | ||||||
| Direct-Acting Spring-Loaded | DA | Spring and diaphragm act directly on the valve | 15–50 | ±10% | Small, steady loads | Bought-out |
| Pilot-Operated | PO | Pilot valve controls main valve diaphragm | 15–150 | ±1% | Variable process loads | Bought-out |
| Pneumatic / Air-Loaded | AL | Air pressure replaces the spring as set point | 15–100 | ±1–2% | Remote set point | Bought-out |
| Electro-Pneumatic Control Valve | EP | Control valve with positioner, 4–20 mA from PLC | 15–150 | ±0.5% | Automated control | Bought-out |
| Self-Acting Temperature & Pressure | ST | Combined pressure pilot and thermostatic pilot | 15–100 | ±2°C / ±5% | Heat exchangers, calorifiers | Bought-out |
| By Service | ||||||
| Steam PRV | S | Cast steel or SG iron body, stainless trim | 15–150 | As operation | Plant steam | Bought-out |
| Clean / Pure Steam PRV | CS | SS316L sanitary body, tri-clamp ends, Ra ≤0.8 µm | 15–50 | ±2% | SIP and clean steam | Bought-out |
| Air & Gas PRV | AG | Soft seat, relieving or non-relieving | 15–80 | ±2% | Compressed air, N2 | Bought-out |
| Water PRV | W | Bronze or SS body, balanced piston | 15–150 | ±5% | Process and utility water | Bought-out |
| Assemblies | ||||||
| PRV Station | STN | Valve with separator, strainer, isolation, bypass, gauges, safety valve | 15–150 | As valve | Standard reduction | JBM |
| Two-Stage PRV Station | STN2 | Two PRVs in series with intermediate gauge | 25–150 | As valve | Ratios above 10:1 | JBM |
| Parallel PRV Station | STNP | Two PRVs in parallel, staggered set points | 25–150 | As valve | Wide turndown, redundancy | JBM |
Models & Sizes: 15 to 150 NB
| Model | NB | Inlet Max [bar] | Outlet Range Direct / Pilot [bar] | Kvs [m³/h] | Capacity 10→3 bar [kg/h] | Station Length [mm] | Station Height [mm] | Station Weight [kg] |
|---|---|---|---|---|---|---|---|---|
| PRV-015 | 15 | 25 | 0.1–8 / 0.2–17 | 2.5 | 330 | 1,800 | 600 | 45 |
| PRV-020 | 20 | 25 | 0.1–8 / 0.2–17 | 5 | 660 | 1,900 | 650 | 55 |
| PRV-025 | 25 | 25 | 0.1–8 / 0.2–17 | 8 | 1,050 | 2,000 | 700 | 70 |
| PRV-032 | 32 | 25 | 0.1–8 / 0.2–17 | 12.5 | 1,650 | 2,200 | 750 | 90 |
| PRV-040 | 40 | 25 | 0.1–8 / 0.2–17 | 20 | 2,650 | 2,400 | 800 | 115 |
| PRV-050 | 50 | 25 | 0.1–8 / 0.2–17 | 32 | 4,200 | 2,600 | 850 | 150 |
| PRV-065 | 65 | 20 | N/A / 0.2–17 | 50 | 6,600 | 2,900 | 950 | 220 |
| PRV-080 | 80 | 20 | N/A / 0.2–17 | 80 | 10,550 | 3,200 | 1,050 | 300 |
| PRV-100 | 100 | 20 | N/A / 0.2–17 | 125 | 16,500 | 3,600 | 1,200 | 450 |
| PRV-150 | 150 | 20 | N/A / 0.2–17 | 280 | 36,950 | 4,400 | 1,400 | 850 |