In modern buildings,where fires are common,fire-resistant steel doors,with their superior fire resistance and structural stability,have become a critical line of defense for protecting lives and property.These fire-resistant doors utilize cold-rolled thin steel plates for the door frame,door leaf frame,and front panel.They are filled with harmless fire-resistant insulation and equipped with fire-resistant hardware,creating a barrier that combines strength and insulation.
According to national standards,fire-resistant steel doors are classified by fire resistance limit into three categories:Class A(1.5 hours),Class B(1 hour),and Class C(0.5 hours).Class A doors are commonly used in core areas such as fire escapes and equipment rooms,while Class B doors are more common in stairwells and elevator vestibules.Class C doors are used in auxiliary spaces such as duct shafts.For example,in a 30-story residential building,the installation of Class A steel fire doors in the stairwell successfully prevented the spread of fire in a simulated fire test,giving residents 45 minutes of golden escape time.
Its structural advantages are reflected in three aspects:First,the composite design of the steel frame and filling material ensures the door maintains structural integrity even at high temperatures;second,the combination of sealing grooves and fire-resistant expansion strips,which expand 2-3 times at temperatures reaching 100°C,completely sealing the gap;and third,high-temperature hardware components,such as locks and hinges,have melting points exceeding 950°C,ensuring normal opening and closing during fires.Furthermore,surface treatments such as thermal transfer printing or powder coating ensure both corrosion resistance and aesthetics.