What is the difference between the standard grades of fire rated doors, A, B and C?
According to the fire resistance limit, the international standard of fire doors is divided into three grades A, B and C.
1. Class A fire door. Its fire resistance is 1.2 hour , generally full steel door. A line of fire doors for the purpose of preventing fires from expanding in the event of fire.
2. Class B fire doors. Its fire endurance is 0.9h, it is a full steel door, a small glass window is opened on the door, and the glass is made of 5mm thick wired glass or fire-resistant glass. Class B fire doors have the main purpose of preventing fires from the openings during fires. C wood fire doors with good performance can also reach Class B fire doors.
3. Class C fire door. His fire resistance is 0.6h, it is a full steel plate door, a small glass window is opened on the door, and the glass is made of 5mm thick wire glass. Most wooden fire doors are in this range.
According to materials, fire doors are divided into two types: wooden fire doors and steel fire doors.
1. Wooden fire door. That is, the surface of the wooden door is coated with a refractory paint, or the decorative fireproof rubber sheet is used for veneering to meet the fireproof requirements. Its fire performance is slightly worse.
2. steel fire doors. That is, it is made of ordinary steel plate, and refractory materials such as rock wool are filled in the door leaf interlayer to meet the fireproof requirements.