The automatic vent valve is a device that automatically removes air by the opening and closing mechanism in the valve body. It is easy to install, small in size, and avoids the trouble of manual operation and management. It is widely used in hot water heating system. At present, most of the automatic vent valves use floating ball opening and closing mechanism. When the valve is full of water, the floating ball will rise and the exhaust port will close automatically. When the air volume in the valve increases, the water level decreases, floating ball drops by its own weight, and the exhaust port is opened to exhaust. The automatic vent valve often fails due to the blockage of dirt in the water, so it needs to be removed for cleaning or replacement. Therefore, a globe valve, gate valve or ball valve need to be installed before the vent valve.

This valve is open all year round, and only temporarily closed when the exhaust valve fails and needs maintenance.