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Device Structure and Function of 70 ° Fire Damper

Release Time：2021-07-15

The following six rules shall be followed when the 70 ° degree fire damper is installed:
First, the 70 ° fire damper can be interlocked with the ventilator and exhaust fan.
Second, it is necessary to check whether the operation organization of the valve is intact and whether the action is sensitive and effective before the valve is installed.
Three, the operation of the valve organization side should be not less than 200mm net space to facilitate maintenance.
Four, fire dampers should be installed in the air duct section close to the wall or floor, fire dampers on both sides of the partition wall of the fire compartment should not be more than 200mm from the wall appearance, and non-combustible data should be used for pipelines and insulation materials within 2.0m on both sides of the fire dampers.
Five, the fire damper fuse piece should be installed in the side of the greater risk of fire.
Six, the fire damper should be set up alone, the fire damper to avoid the fire when the deformation of the pipeline affects its function.

Fire damper is normally open and closed at 70 ℃,150 ℃ or 280 ℃. It is generally installed at the place where the air duct passes through the firewall and structural deformation joint to play the role of fire control. It can set the output electric signal. When the temperature exceeds 70 ℃,150 ℃ or 280 ℃, the valve is closed and the linkage feed (supplement) fan is closed.
The fire damper is installed in the air duct system of the central air conditioner. The working principle is to use the temperature control of the extremely fusible alloy installed on the valve, and the effect of gravity and the spring mechanism. When a fire occurs, the flame invades the air duct, and the high temperature causes the fusible alloy on the valve to melt, or the memory alloy to deform to make the valve automatically close. It is used for occasions where the air duct and the fire zone run through.
On the air duct of the air conditioning system, the purpose of installing the fire damper is to cut off the conveying air flow quickly when a fire damper disaster occurs to prevent the fire from spreading. When a fire occurs, the air duct is affected by the surrounding temperature and the temperature rises. When the fire causes the air duct to reach a certain temperature, the fusible sheet melts, and the valve plate originally connected by the fusible sheet is immediately disconnected from the fusible sheet to prevent the airflow from passing through, the installation of electrical signals and interlocking devices on the fire valve can make the valve plate send a signal when it is closed, so that the fan stops running.

fire valve installation position:
(1) On the main air duct of the air outlet of air conditioning equipment (fresh air unit, air conditioning unit, etc.).
(2) When the air duct crosses the fire compartment.
(3) When the air duct crosses the expansion settlement joint of the building structure.
(4) When the air duct cannot be avoided, the fire damper passes through a flammable workshop or room.
Fire damper can be divided into self-weight plate type, fire control valve and other types, can be manually reset, the action temperature of the fusible sheet is 70 ℃.
A complicated air supply and smoke exhaust system has complicated pipelines. In the air supply system, the air sent by the blower must be distributed to each branch pipe through the main pipe. In the exhaust or smoke exhaust system, the air or smoke is collected from each branch pipe to the main pipe and then enters the exhaust fan for exhaust. Then, no matter in the air supply system or the smoke exhaust system, if there is no obstruction, the air supply volume and smoke exhaust volume cannot be controlled, there is a lot of air supply and smoke exhaust in the parts that do not need air supply or smoke exhaust, while the parts that need air supply or smoke exhaust do not send air, smoke exhaust or only a small amount of air supply and smoke exhaust. In order to cut off the pipeline of the smoke exhaust part without air supply or smoke exhaust, this requires a valve device.