A pressure reducing valve automatically limits system water pressure to a preset level, typically 12 to 30 PSI, protecting pipes, fittings, and equipment from pressure damage. These valves sense downstream pressure and throttle inlet flow when maximum pressure is exceeded. They are essential safety devices in closed-loop hydronic systems where thermal expansion creates rising pressure.
Operation and Ratings
Residential pressure reducing valves are sized between 0.5 and 1.5 inches and handle flow rates from 5 to 60 GPM. Most systems use 15 to 20 PSI settings for radiant heating and 25 to 30 PSI for baseboard systems. Valve accuracy maintains pressure within 2 PSI of the setpoint under normal operating conditions.
System Protection
Without pressure reducing valves, thermal expansion can increase system pressure from 12 PSI to 60 PSI or higher, risking pipe rupture and leaking connections. These valves work in combination with expansion tanks to maintain safe operating pressures. Periodic testing and adjustment ensures continued protection throughout system service life.