PT valve is a pressure and temperature safety valve, for pressure-type solar water heaters (closed containers) and can protect system by temperature and pressure. It is a safety protection device for solar water heaters.
In the tank of solar heating system, when water temperature rises, the volume of the water expands, and the pressure inside increases at the same time. PT valve has two working on modes, pressure and temperature.
1. When the tank pressure increases to the set value, the PT valve will open and protect the solar water heating system by draining the pressure.
2. When the temperature of tank increases to the set value, PT valve open then water drain out meanwhile cold water enters the tank to protect the solar water heating system by reduce temperature and pressure inside.
PT valve opens when either temperature or pressure is met the set value.