Recommend Instructions; one way is to exhaust port of the exhaust valve and damper modules cancel purposes outlet into a single louvers; second method is to put a normally closed damper on each electric charge of the smoke was changed normally open 280 degrees to close the damper, control module replaced by a general monitoring module. Both methods achieve the same fire damper manufacturer specifications, and the actual control is also very reliable. Damper-off damper principle of the system according to the requirements, the system is disabled and normal operation is in the open state, such as in the piped gas temperature is below the selected fusible metal melting point of the damper, normal operation state, the valve is open. Only when operating conditions beyond the normal use of the state, it automatically closes the valve, to the role of security. Damper model, Chen Yu-conditioned (certification), fire dampers supplied by Wu Cheng Chen-yu air-conditioning Limited. Wu Cheng Chen-yu air-conditioning Co. (www.wccykt.com) is an industry leader in Shandong Dezhou, fans, ventilation equipment, over the years, the company implement the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs . Chen Yu-conditioned in leadership with the staff warmly welcome all inquiries negotiations to create Chenyu air conditioning better future.