Operator terms · Water
What is a pressure reducing valve (PRV)?
A pressure reducing valve, or PRV, lowers and holds the downstream water pressure at a set level. Distribution systems use PRVs to protect low-elevation areas from the high pressure that would otherwise reach them, keeping pressure safe across different ground heights.
Last reviewed 2026-08-03
Why pressure needs controlling
Elevation changes make pressure vary across a system. A home far below the storage tank can see very high pressure. A PRV set for that zone drops the pressure to a safe range before it reaches those customers.
Where it fits
PRVs are placed between pressure zones. Upstream pressure can be high, but the valve holds the downstream side at its set point, so the piping and fixtures beyond it are protected.
Common questions
- What does a PRV do?
- It lowers and holds the downstream pressure at a set level.
- Why is it needed?
- Elevation differences can push pressure too high for low-lying areas.
- Where is it installed?
- Between pressure zones in the distribution system.