Thermostatic Control Valve

This valve is normally open and if temperature increase, it gets gradually closed. This valve and its sensor work based on expansion principle of liquids. Its sensor should be placed inside the tank or in direction of the fluid. There is a kind of expandable oil inside the sensor. When temperature of fluid increases, it makes the oil expanded and this changing of volume moves pin of operating element. This extra force affects seat and plug and changes space between them and in this way, fluid discharge can be controllable.