Steel fire doors are a common fire protection facility used to stop the spread of fire and protect the safety of people. The fire resistance of steel fire doors refers to the time they can withstand in a fire, and is one of the important indicators for assessing the quality of steel fire doors. Generally speaking, the fire resistance time of steel fire doors varies according to the material, structural design and installation of the fire doors.
First of all, the material of steel fire doors has a key impact on its fire resistance time. Common steel fire door materials include cold rolled steel plate, stainless steel plate, etc. The fire resistance of the material depends on the melting point and thermal conductivity of the material. Generally speaking, steel has a high melting point, which can prevent the flame from entering the door in a short period of time, thus prolonging the fire resistance time of the fire door. Stainless steel material will form a dense oxide skin at high temperature, which can effectively retard heat conduction and improve the fire resistance of fire doors.
Secondly, the structural design of steel fire doors also has an important impact on its fire resistance time. The fire door is generally composed of steel frame, fireproof filling material, fireproof door fan and door lock and other components. The structural design of the steel frame should take into account that the gap between the door leaf and the door frame should be as small as possible, so as to reduce the penetration of flame and smoke. The fireproof filling material is generally made of fireproof materials such as fireproof silicate board or asbestos board, which have good flame-retardant properties and can effectively resist heat conduction and flame spread. The surface of fire-resistant door leaf is covered with fire-resistant paint or fire-resistant coating, which can improve the fire-resistant effect of the door leaf. The door locks should also adopt fireproof locks to ensure that the fire doors always remain closed during fire.
In addition, the installation of steel fire doors also directly affects their fire resistance time. The installation of fire doors should comply with relevant fire safety codes and standards, including the installation position of fire doors, fixing methods and sealing seam treatment and other requirements. Improper installation may cause the gap between the door and the door frame to be too large, resulting in easy penetration of flame and smoke, thus shortening the fire resistance time of the fire door. Therefore, the installation process should be carried out in strict accordance with the specifications, and the construction quality should be tested and accepted.
It should be noted that the fire resistance time of steel fire doors can not be determined solely from the material, structure and installation factors, but also need to consider the impact of other factors, such as fire, outside temperature and ventilation. Different levels of steel fire doors correspond to different fire resistance time, generally can be divided into A level, B level, C level, etc. A level fire door can generally withstand fire for more than 2 hours, B level fire door is generally more than 1 hour, C level fire door is generally more than 0.5 hours.
In conclusion, the fire resistance time of steel fire doors in fire depends on several factors, including materials, structural design and installation. Reasonable material selection, scientific design and correct installation can improve the fire resistance performance of fire doors and ensure the time window for safe evacuation of people. Therefore, when selecting and installing steel fire doors, these factors should be fully considered and the appropriate fire door level and fire resistance time should be selected according to actual needs.
