An expansion tank is a small vessel or tank that is used to reduce the excessive pressure of closed water heating system or domestic water heating, cooling system and air condition. Expansion tanks are also used in many other types of systems such as steam water supply expansion system, fire water supply system, frequency conversion water supply system, boiler water feeding system etc.
Expansion tank consist of a main body, bladder, water inlet and outlet valves and air inlet valves. Its body is made up of either steel or baked-enamel coating carbon steel.
Expansion tanks are installed in water supply valves of the system. It reduces the thermal pressure in water heating system when water gets heats this will prevent the pressure from getting to high. The expansion tank is filled with compressed air before it is released from the factory and its compressibility cushion shock will absorb the excess pressure. If expansion tank is not installed it may cause damage to inlet and outlet valves and water heating system too.