The fire resistance limit of Xuanyuan Gate refers to the time from fire exposure to loss of stability, integrity or thermal insulation when building components are subjected to fire resistance test according to the time temperature standard curve. The fire doors in China are divided into Class A, Class B and Class C according to the fire resistance limit to meet the requirements of different levels of buildings. The fire endurance of Class A fire door is 1.2h, that of Class B fire door is 0.9h, and that of Class C fire door is 0.6h.
The scope of use of various fire doors is specified in accordance with GB50045-95 (Code for Fire Protection Design of High rise Civil Buildings) and GB50016-2006 (Code for Fire Protection Design of Buildings); When opening doors, windows and openings on the firewall, Class A fire doors shall be provided. When opening doors on partitions with a fire resistance limit of no less than 2.0h, Class B fire doors shall be used. However, the fire endurance of fire doors and firewalls differ greatly. The fire performance of fire doors in the time after their fire endurance is unknown, which will form a fire hazard.
The product standards for fire doors GB12955-91 (General Technical Conditions for Steel Fire Doors) and GB14101-93 (General Technical Conditions for Wood Fire Doors) also have corresponding provisions and requirements for the design and installation of fire doors. The production of fire doors shall be carried out according to the requirements of the current national standards for fire doors. The door leaf of Class A fire doors is 45-55mm thick, filled with aluminum silicate fiber wool inside, the door leaf of Class B fire doors is 40-50mm thick, filled with aluminum silicate fiber wool and rock wool inside, and the door leaf of Class C fire doors is about 40mm thick, filled with fire boards and rock wool inside. The key to the fire resistance of fire doors is often the internal filler materials.
The fireproof performance of fireproof doors in Britain, France, the United States and Japan is generally lower than that of China, but the requirements of developed countries such as Europe and America for fireproof doors have other advantages. The American standard NFPA and UL10 only require the fire resistance and heat insulation of the first 30 minutes for fire doors, with the temperature not exceeding 232 degrees, and the integrity ranging from 0.5 to 3.0 hours. The inspection method is not only to test according to the standard temperature rise curve, but also to test through the actual fire, so as to obtain a performance-based fire door design scheme, which is more practical. Malaysia Standard MS1073 also has basically similar requirements. British standard BS476 divides fire doors into fully insulated fire doors and semi insulated fire doors. The requirements for fire resistance and thermal insulation time of fire doors are not high, such as 20min, 30min, but the fire resistance integrity requirements meet the corresponding design time requirements, such as 2.0h, 3.0h, or even 4.0h
At present, the Consumer Science Research Institute of the Ministry of Public Security is revising (General Technical Conditions for Steel Fire Doors) and (General Technical Conditions for Wood Fire Doors). The principle of revision is that the revised standards are more practical. Fire doors are classified as Class A fire doors and Class B fire doors. Class A fire doors are also called fully insulated fire doors. Fire doors that can meet both fire integrity and fire insulation within the specified time are used in important places, such as fire doors for nuclear power plants and fire doors for important parts. The fire resistance rating can be divided into 1.0h, 1.5h, and 2.0h. Class B fireproof door is also called semi insulated fireproof door. Its fire resistance and thermal insulation are only required to be 0.5h, and its fire integrity is 0.5h, 1.0h, 1.5h, 2.0h, 2.5h, 3.0h, 4.0h. As the fire door is used as the access door, it can basically meet the evacuation of people at the fire site within 0.5h after the fire, and combustible materials are generally not allowed to accumulate near the fire door, so the fire door will not cause a fire hazard if it is not insulated after 0.5h. The Xuanyuan door fire door installed on the firewall can prevent the spread of fire and complement the role of the firewall