The fire damper is a valve used to block the passage of smoke and flames from the fire zone, and to meet the requirements for fire resistance stability and integrity within a time limit. In order to reduce the loss caused by fire to a small extent, it is necessary to adopt useful fire prevention and smoke control measures to control the extension of the fire. The reasonable setting of fire dampers in ventilation, air conditioning, and smoke control systems has played an important role.

The purpose of installing a fire damper in the air duct of an air conditioning system is to quickly block the conveyed air flow in the event of a fire and avoid the extension of the fire. When a fire occurs, the temperature of the air duct increases due to the influence of the ambient temperature. When the fire causes the air duct to reach a certain temperature, the fusible piece will melt, and the valve plate originally connected by the fusible piece will then be disconnected from the fusible piece, blocking the passage of air flow. In order to stop continuous air supply to the system, electrical signals and interlocking devices are installed on the fire damper, which can cause the valve plate to announce a signal when closed, causing the fan to stop working.

In addition, the fire damper also has the effect of preventing smoke and fire. In the air supply system, it is necessary to distribute the air sent by the forced draft fan through the main pipe to the branch pipe; In the smoke exhaust system, the smoke flows from the branch pipe to the main pipe and then enters the smoke exhaust fan for exhaust. When a fire breaks out in a building, in the ventilation and air conditioning systems, in order to prevent the fire from extending through the air supply system, when the temperature of the gas in the air supply system reaches 70 ℃, the fire damper organizes a fuse action, and the valve is also quickly closed to block the passage of smoke and fire extending along the air duct. Similarly, in the smoke exhaust system, when a fire occurs, the smoke exhaust valve is opened to exhaust smoke. In order to cut off the activity of high-temperature smoke in the smoke exhaust pipe and prevent the fire from extending to another fire compartment, when the temperature of the exhaust smoke reaches 280 ℃, the smoke exhaust fire damper and the fuse on the smoke exhaust port act, and it is necessary for the valve to automatically close to prevent smoke exhaust. It can be seen that the fire damper and smoke exhaust valve achieve the smoke isolation and fire resistance effect of "on" and "off".