Product Principle: Edit installed in the central air-conditioning duct system works extremely fluxing temperature control, by the action of gravity and spring mechanism closes the valve. When a fire occurs axial fan fire dampers, fire dampers duct invasion, high temperature melting fusible alloy valves, or to make memory alloy is deformed so that the valve automatically closes airflow duct for the occasion with the fire district through regulation Valve Instructions .doc Rating: 5/5 10 .pdf manual air flow control valve Rating: 0/5 151 more library-related documents >> axial fan ventilation dampers _ Plumper (certified) _ Qinhuangdao damper by Dezhou Plumper provide ventilation plant. Dezhou Plumper ventilation plant (www.frtfsb.com) (www.frtfsb.com) is a leader in 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.