Tech Notes: Water Pressure The Role of the PRV


Pressure Reducing Valves, or PRVs, are sometimes installed in the water service line to adjust the service pressure to around 50 psi.  Your plumber can adjust the pressure level set point by adjusting the nut at the top of the unit.  Once calibrated, the unit should do its job and not need servicing for many years. A life of 15-20 years would be typical before needing to be replaced.


The PRV helps to maintain a reasonable service pressure to the home, in the 25-75 psi range, when main pressures are higher than that.  All other things being equal, water pressure tends to be highest in the lower elevations of a water distribution system.  For example, in some of the lowest elevations of our system, main distribution pressures can be 130 140 psig. The PRV serves to provide a reduction in these cases to a more manageable pressure range and in addition can protect the house piping/fixtures and the meter set from excessive pressure and surges.