Pressure reducing valves (PRVs) automatically reduce and maintain a constant downstream pressure regardless of upstream pressure fluctuations and downstream demand changes. They are essential for steam distribution systems, compressed air networks, and process gas supply.
AQ Process Systems sources and exports self-acting (direct-operated) PRVs for simple applications, pilot-operated PRVs for higher accuracy and capacity, and control valve type pressure regulators for the most demanding applications. Available in sizes from 1/2" to 24" for steam, air, gas, and liquid service.
For steam pressure reduction, we supply complete pressure reducing stations including the PRV, upstream and downstream isolation valves, strainer, safety valve, pressure gauges, and bypass arrangement, designed per local codes and best practice.
| Product | Specification | Description |
|---|---|---|
| Self-Acting PRVs | ||
| Direct-Operated PRVs | 1/2", 6" | Steam, air, gas | Simple regulation | Self-contained pressure reducing valves with integral sensing, no external power or pilot required. For simple, small-to-medium flow applications. |
| Bellows-Sealed PRVs | 1/2", 3" | Clean steam, sterile applications | Self-acting PRVs with bellows-sealed construction, preventing process fluid contact with the spring chamber. For clean steam and pharmaceutical applications. |
| Pilot-Operated PRVs | ||
| Pilot-Operated PRVs | 1", 24" | Steam, gas, liquid | Higher accuracy | Pilot-operated pressure reducing valves, the pilot senses downstream pressure and controls the main valve for tighter regulation accuracy (±1-3%). |
| Surplussing PRVs | Overpressure relief + regulation combined | Surplussing (back-pressure) regulators that open to relieve excess downstream pressure, often used in combination with a reducing PRV. |
| Station Equipment | ||
| Pressure Reducing Stations (Packaged) | Complete skid | PRV + isolation + safety | Complete pressure reducing station skids including PRV, upstream strainer, isolation valves, safety valve, pressure gauges, and bypass arrangement. |
| Desuperheaters | Spray type | Steam temperature control | Desuperheaters for reducing steam temperature downstream of the PRV, spray-type water injection controlling superheat. |
Self-acting PRVs use a spring-loaded diaphragm or piston that directly senses downstream pressure, simple, reliable, no external power needed, but limited accuracy (±5-10%). Pilot-operated PRVs use a small pilot valve to sense pressure and control the main valve, providing tighter accuracy (±1-3%), higher capacity, and better response to rapid load changes.
PRV sizing depends on the maximum steam flow rate, inlet pressure, outlet pressure, and allowable pressure drop. Oversizing causes hunting (rapid opening/closing), while undersizing limits capacity. Provide us with your steam flow rate, inlet and outlet pressures, and we will size the correct PRV and recommend the appropriate type.
Yes. We supply packaged pressure reducing stations on a skid or baseframe, including the PRV, upstream isolation valve, Y-strainer, downstream isolation valve, safety valve (set to the reduced pressure system MAWP), pressure gauges, and manual bypass arrangement. Designed per customer specifications and local codes.
A desuperheater reduces steam temperature by injecting a controlled amount of water into the superheated steam downstream of the PRV. It is needed when the reduced-pressure steam would otherwise be superheated (e.g., reducing from a high-pressure superheated header to a low-pressure saturated steam system). We supply spray-type desuperheaters sized for the steam flow and temperature requirements.
Yes, that is their primary function, maintaining a constant downstream pressure despite upstream pressure variations. Pilot-operated PRVs handle wider upstream pressure swings more accurately than self-acting types. For severe upstream pressure fluctuations, we may recommend a two-stage pressure reduction arrangement.
Share your valve specification, size, pressure class, material, end connections, we respond within 24 hours.