280 degrees damper must be closed at a high temperature, it will signal back to the controller via input module round dampers, then control exhaust fan to stop. Prevent the fire from spreading to other fire district through exhaust pipes. On the exhaust fan inlet manifold should be set when the flue gas temperature exceeds 280 ℃ can turn itself off when the smoke damper fire damper, and should be interlocked with the exhaust fan, so that the flue gas exhaust pipe when the temperature exceeds 280 ℃ can itself off, to prevent smoke spread to other parts. Otherwise, turn off the exhaust fans only, can not prevent the spread of smoke and fire through the pipeline. Exhaust valves, with the above, each unit different names put smoke dampers, some based on its operating temperature is called the exhaust valves, and some based on its use of nature called the damper, but only for the common damper device side blown fuse metal into that kind of 280 degrees. Automatic smoke damper (Metro Engineering) Fire subway ventilation and air conditioning systems, exhaust valve having automatic fire alarm equipment and gas extinguishing system linkage control functions. Each automatic smoke dampers with two independent electric damper control signal 150 ℃, respectively, by EMCS, gas consumption system to monitor, control signals are DC24V ± 10% signal. Each automatic smoke dampers have six independent feedback signal (three open place, three off place) feedback signals are normally open dry contact signal. Damper 70 ℃, rich ventilation equipment (certified), the damper is provided by Dezhou rich ventilation plant. Dezhou rich ventilation plant (www.frtfsb.com) (www.frtfsb.com) is an industry leader in Shandong Dezhou, fans, ventilation equipment, over the years, the company implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, the maximum Limits to meet customer needs. Rich ventilation equipment in leadership with the staff warmly welcome all inquiries negotiations to create rich, ventilation a better future.