Caleffi 502640 Air Vent (1/2in)

Automatic radiator air vent valve is designed to remove any air trapped inside the heat emitters both during the filling of the system and in normal operation. The automatic air discharge happens when the hygroscopic cellulose fibre discs are dry. As air is vented and water contacts the hygroscopic discs, they increase their volume by 50% which cause the discharge vent to close.

Float type automatic air vent designed to vent air that is released from the water while being heated.