Fire damper is a valve installed in ventilation, air conditioning, and smoke exhaust ducts, and its working principle is based on temperature sensing. When the temperature of the flue gas inside the pipeline reaches the preset melting temperature (usually 70 ℃ or 280 ℃), the fusible alloy or memory alloy in the fire damper will deform or melt, triggering the valve's closing mechanism. In addition, fire dampers can also be opened and closed by electric or manual means.

Preventing the spread of fire: Fire dampers can quickly close when a fire occurs, cutting off the path of the fire spreading through pipelines and preventing further expansion of the fire.
Preventing the spread of smoke: The closure of fire dampers can effectively prevent the spread of toxic smoke, creating favorable conditions for personnel evacuation and firefighting rescue.

According to different usage scenarios and functions, fire dampers can be divided into various types, including but not limited to the following:
70 ℃ fire damper:
Function: Mainly used for smoke prevention and air supply systems, in conjunction with air supply fans. When the temperature inside the air supply duct reaches 70 ℃, the fire damper automatically closes to prevent the spread of fire and smoke through the duct.
Features: The blades are usually in the open state and automatically close in case of a fire. It has an automatic reset function (manual reset is required).
280 ℃ fire damper (smoke exhaust fire damper):
Function: Mainly used in smoke exhaust systems, in conjunction with smoke exhaust fans. When the temperature inside the smoke exhaust duct reaches 280 ℃, the fire damper automatically closes and the smoke exhaust fan stops to prevent damage to the fan caused by high-temperature smoke.
Features: The blades are usually in the open state and automatically close in case of a fire, requiring manual reset. Some products also have temperature (smoke) electrical signal linkage function, which can be linked with the fire control system.
Fire control valve:
Function: Installed on ventilation and air conditioning system ducts with fire prevention requirements, used to regulate air volume and prevent the spread of fire.
Features: The blades are usually in the open state, and the air volume can be adjusted as needed. When the temperature inside the pipeline reaches 70 ℃, the fire control valve automatically closes and outputs a closing signal.
Smoke and fire control regulating valve:
Function: Installed on ventilation and air conditioning system pipelines with smoke and fire prevention requirements, used for smoke (temperature) signal linkage to close valves and prevent the spread of smoke and fire.
Features: The blades are usually in the open state and have a smoke (temperature) electrical signal linkage closing function. When a fire signal is received, the valve automatically closes and outputs a closing signal. At the same time, the valve also has the function of adjusting the air volume in stages of 90 ° five equal parts.

Installation location: Fire dampers should be installed at critical locations of ventilation, air conditioning, and smoke exhaust ducts, such as through firewalls, floor slabs, machine room partitions, etc. The smoke exhaust fire damper should be installed at the connection between the smoke exhaust fan inlet main pipe or smoke exhaust branch pipe and the vertical air duct.
Setting requirements:
Normally open and normally closed: Depending on the usage scenario, the fire damper can be set to either normally open or normally closed. Normally, the blades of the normally open fire damper are in the open state and automatically close in case of a fire; Normally, the blades of a normally closed fire damper are in a closed state, and in the event of a fire, it is powered on and opened by the control center.
Linkage control: For fire dampers that require linkage control, they should be connected to the fire control system to achieve linkage with automatic fire alarm systems, smoke exhaust fans, etc.

Regular inspection: Regularly inspect the fire damper to ensure that it is in good working condition. The inspection includes checking whether the valve is flexible in opening and closing, whether the sealing components are intact, and whether the melting alloy or memory alloy is damaged.
Cleaning and maintenance: Clean and maintain the fire damper to remove impurities such as dust and oil, and prevent them from affecting the normal opening and closing of the valve.
Replace damaged parts: If the components of the fire damper, such as melting alloy, memory alloy, seals, etc., are found to be damaged or aged, they should be replaced in a timely manner to ensure their normal function.