How to size/select a pressure reducing valve
Factors which play the most important role in selecting a proper pressure reducing valve include:
- Line size - should match the valve size, i.e. 3/4" valve for 3/4" line, etc.
- Maximum incoming pressure - these may vary by model, but must always be greater than the incoming water pressure. Typical ranges are 300-400 psi.
- Outlet pressure range - adjustable on most valves, usually within 25-75 psi. Must meet plumbing system operating pressure.
- Additional features - some models may incorporate a strainer to protect the valve seats from fouling or offer in-line service design which allows for repair/replacement of components without removing the entire valve.
Additional things to keep in mind:
1. Do not confuse pressure reducing valves with pressure relief valves (PRV’s). While the abbreviation is coincidentally the same, these are entirely different both in structure and intended use.
2. Pressure reducing valves listed in this category are not backflow preventers. To protect the incoming water supply from cross contamination caused by backflow, siphon or backpressure - a separate device is needed.
3. These valves have a factory (standard) setting, which is commonly 50 psi. If this setting is too high/low for the plumbing system, the valve would need to be adjusted - this is generally done by screwing the topmost bolt in/out. A pressure gauge is recommended to monitor the outlet/outgoing pressure.
