WHAT IS A TEMPERATURE OR PRESSURE RELIEF VALVE?
A temperature or pressure relief valve is a safety device to bring down the temperature
and/or pressure of water in a heating or hot water system when it exceeds a specific
Temperature or pressure relief valves are usually fitted into water systems where
the temperature or pressure of the system or storage cylinder (such as an unvented
hot water cylinder) could become dangerously high and cause it to burst.
HOW DOES A TEMPERATURE OR PRESSURE RELIEF VALVE WORK?
Usually pressure relief valves consist of a valve body with an opening head held in
place by a spring.
The valve head will open when the pressure in the valve body increases beyond the
strength of the spring.
In the picture shown, the red valve head will lift under excessive pressure and allow
water to flow through the valve body out of the system and into a discharge pipe.
The same principal applies in a temperature relief valve.
Instead of a pressure sensitive spring though, a temperature sensitive mechanism pushes
open the valve when the system water temperature exceeds a pre-set limit.
PRESSURE RELIEF VALVE