由广东省商业制冷设备公司机械厂和广州市消防科学技术研究所联合研制,广州市南粤防火门厂生产的SL系列钢质防火门,经一年多来的研制和试产,产品经国家防火建筑材料质量监督检测中心检测,该门的耐火极限为75分钟,符合GB7633—87防火门甲级标准。由广 Developed jointly by Guangdong Commercial Refrigeration Equipment Company Machinery Factory and Guangzhou Fire Science and Technology Research Institute, the SL series of steel fire doors produced by Guangzhou Nanyue Fireproof Door Factory has been developed and tested for more than one year. The products have been fireproofed by the state. The building material quality supervision and inspection center detected that the fire resistance limit of the door is 75 minutes, which is in line with GB7633-87 Fire Door A standard. By wide