Standard classification of fire doors: What's the difference between A, B and C?

The standards of fire doors are divided into three grades: A, B and C. Their difference is that according to the fire resistance limit and thermal insulation performance, the first-class fire door is not less than 1.5 hours, the second-class fire door is not less than 1 hour, and the third-class fire door is not less than 0.5 hours.

The fire time of fire doors is mainly determined by fire boards. In this respect, the performance of fire boards used in Class A fire doors is generally better than that of Class B fire doors, so the overall performance is stronger than that of Class B fire doors. In addition, Class A fire doors are especially suitable for those occasions that require fine grinding before electroplating, excellent vibration, mirror polishing with hand tools, mirror polishing in electric heating tube and so on. Such as vibration polishing of various furniture hardware fittings, cutting and polishing of hand tools, surface vibration polishing of daily products and self-painted fittings, etc.

According to the new national standard GB_ 12955-2008, which came into effect on June 65438+1October 65438, 2009, the accredited laboratory designated by the Economic Department of the Ministry of Fire Protection is called the fire door. The fire door defined by NFPA and IBC codes in the United States is "any combination of door leaves, door frames, hardware and other accessories that can provide a certain degree of fire protection for the opening."

Extended data:

The new national standard GB_ 12955-2008 introduces the concepts and requirements of local and non-insulated fire doors from international and foreign standards, and the classification of fire doors is changed from simple insulated fire doors to completely insulated fire doors (Grade A), locally insulated fire doors (Grade B) and non-insulated fire doors (Grade C).

At the same time, the fire resistance limits of the original class A, B and C fire doors are adjusted to 1.5h, 1.0h and 0.5h, which enriches the types of fire door products in China and increases the choice of practical application. For applications that only require partial insulation or fire integrity of fire doors, you can choose partial insulation or non-insulation fire doors.

The new standard also stipulates that fire-proof and heat-insulating materials that are harmless to human body should be used when the door leaves are filled with materials to reduce the impact on human health.

These regulations not only make the setting of fire doors more reasonable, but also reduce the production cost and raw material consumption of fire doors. Meet the requirements of environmental protection and building a conservation-oriented society. At the same time, the new standard also increases the contents and requirements of steel-wood thermal insulation fire doors and other materials thermal insulation fire doors, which provides technical basis for the application of new materials and technologies and the production inspection of new fire doors, and expands the development space of fire door manufacturers.

References:

Baidu encyclopedia-fire door