How to Install a Pressure-Reducing Valve

Municipal pressure varies. Anything over 80 psi at the main stresses fill valves, water heaters, and toilet fills — a PRV brings it down to a safe 55–65.

Common causes

• Street pressure above 80 psi
• Repeated toilet fill valve failures
• Water hammer with quick-close valves
• Excess wear on appliances

Step-by-step

1. 01Gauge street pressure at an outside hose bib
2. 02Cut in a PRV on the main just after the shut-off
3. 03Set the outlet pressure to 55–65 psi
4. 04Install an expansion tank on the water heater if adding a PRV

When to call Northbridge

• Street pressure over 80 psi
• Existing PRV over 10 years old and failing
• New PRV requires an expansion tank
• Water hammer needs arrestors + PRV combo