Besides the functions of ordinary doors, fire doors also have the functions of fire prevention and smoke isolation. Class A fire doors (fire resistance limit of 1.2h) should be installed when it is necessary to pass between the fire zones of the building. Once a fire breaks out in the building, it can prevent or delay the spread of the fire to a certain extent.
The fire retardant door of commercial buildings should be light, beautiful and durable in addition to certain fire resistance standards. Fire doors can be divided into Class A, Class B and Class C fire doors according to their fire resistance limits. Its structure and quality have a direct impact on its fire-proof and smoke-proof performance. The fire-proof standards of fire doors are mainly whether the stability and integrity of the doorways are destroyed and whether they lose their fire-proof function.
According to NFPA and IBC specifications, the "fire door" is any combination of fire doors, doors, hardware and other accessories that can jointly provide a certain degree of fire protection for the opening.
According to the national standard CNS 11227/A3223 fire door heating test results, if the fire door specimen meets the following conditions (1) to (5), it can be regarded as meeting the requirements of Class A (with heat resistance) fire door, and if it only meets the following conditions (1) to (4), it can be regarded as meeting the requirements of Class B (without heat resistance) fire door.
1. No deformation, damage, shedding, peeling, etc. that are considered harmful by fire protection have occurred.
2. No flame reaching the unheated surface of the specimen and cracks and holes harmful to fire prevention were produced.
3. Any part of the periphery (door leaf) of the test body in the heating test has no more than half of the thickness of the door leaf.
4. No combustion flame is produced on the unheated surface of the test specimen in the heating test.
5. In the heating test, the temperature of the high non-heating surface of the test sample does not exceed 260℃.
To sum up, within a certain period of time, the complete door wholesale set, including door leaves, door mullions and hardware fittings, can meet the requirements of fire resistance, flame shielding and heat insulation, that is, it can relatively maintain the basic performance of being stable, preventing fire smoke from penetrating and blocking heat source conduction in a fire scene. No matter what kind of material it is, it must be tested by the laboratory designated by the Ministry of Economic Affairs.