High capacity pressure and temperature relief valves designed to provide protection against over pressurisation or extreme temperatures over 95°C which can occur within an unvented hot water system, if the input temperature or pressure controls fail.
The valves are designed to be fitted to the upper portions of a hot water cylinder as this is where the hottest temperature within the system will be found. If the valve is opened it will lift off its seat and release the water to waste, thereby reducing the pressure or temperature within the cylinder. The larger FVMX valves are especially suited for commercial applications.