(20 17) air valve is the control and adjustment mechanism of distribution network, and only the air valve with control function is ().

Air valve is the control and adjustment mechanism of air distribution network. There are check valves, fire valves, smoke exhaust valves and so on. The check valve controls the flow direction of the airflow to prevent the airflow from flowing backwards; The fire damper is fully opened and closed under normal conditions. In case of fire, the airflow is cut off to prevent the fire from spreading through the air duct and closed at 70℃. The smoke exhaust valve is normally closed, fully opened when exhausting smoke, and opened at 80℃ to eliminate indoor smoke.