Smoke damper normally closed (NC, open electrical signal processing dampers, 280 degrees fuse closed, fire dampers, or manually shut down) are commonly used in exhaust systems, exhaust fan can be installed at the inlet of a fire When the control is turned by the consumer control room, can be turned off when the chain closes the exhaust fan. Damper performance standards: product standards GB15930-1995 "fire damper test method" engineering standards GB50045-95 "fire protection design of tall buildings" GB50016-2006 "architectural design code for fire protection" GB50243-2002 "Construction Quality Acceptance of Ventilation and Air Conditioning Engineering "Product Name: __ off the air flow control valve regulating valve _ leafy leafy electric off valve Product Code: DFT damper, Yanda air conditioning, new dampers supplied by Wu County Yanda air-conditioning plant. Damper, Yanda air conditioning, new damper is Wu County Yanda air-conditioning plant (www.wcydkt.com) (www.wcydkt.com) this year introduced a new upgrade, the above picture is for reference only, please dial this page Phone or pictures on obtain the latest information, contact: Wu Yusong.