class B fire door

Understanding Class B Fire Doors: Technical Specifications and Insights from Guangdun Door Industry Co., Ltd.

As a leading player among fire door manufacturers, Guangdun Door Industry Co., Ltd. brings extensive academic expertise and industry experience to the production of Class B fire doors. These essential safety features play a critical role in fire protection, ensuring the safety of buildings and their occupants.

Key Technical Parameters of Class B Fire Doors

1. Fire Resistance Performance: Class B fire doors are designed to have a fire resistance duration exceeding 1.00 hour, adhering to the A1.00 (Class B) fire resistance requirements. All technical indicators meet the standards set by GB12955-2008, ensuring comprehensive compliance.
2. Filling Materials: The filling materials used in these doors conform to the A1 level of combustion performance outlined in GB8624-2006, as well as meeting the ZA2 level of smoke toxicity specified in GB/T20285-2006.
3. Material Composition: Our Class B fire doors are crafted from high-quality cold-rolled steel plates provided by Baosteel in Shanghai. The door leaf is made of two 0.8mm thick steel plates, while the frame boasts a thickness of 1.5mm and an overall leaf thickness of 50mm. The cover seam plate must be securely connected and should not obstruct the door’s normal operation.
4. Seal and Finish Quality: Proper fire sealing materials are integrated into the gaps between the door frame and the door leaf, ensuring compliance with GB16807 standards. The exterior finish should be smooth and free from noticeable dents or mechanical damage, with coatings applied uniformly.
5. Lock and Hinge Integrity: Fire locks, hinges, sequence controllers, and fire bolts must be certified by national testing authorities, ensuring that their fire resistance meets specified requirements. Additionally, fire door closers are required to be installed and tested for compliance with GA93.
6. Thermal Performance: Class B fire doors must maintain a fire insulation performance where the average temperature rise on the unexposed side does not exceed 140℃, with a maximum rise of 180℃. The integrity of the door must also be intact, with no flames lasting over 10 seconds on the unexposed side, ensuring that no ignition of any insulating material occurs.
7. Thermal Insulation Coefficient: The thermal transmission coefficient (K) is set at 2.3 W/(㎡·K), underscoring the energy efficiency of our doors while maintaining fire safety standards.

Conclusion

At Guangdun Door Industry Co., Ltd., we prioritize the production of high-quality Class B fire doors that meet stringent standards and provide optimal safety. Our commitment to excellence is reflected in our rigorous testing procedures and adherence to national regulations. As the market continues to evolve, we remain dedicated to leveraging our academic foundation and innovative technologies to enhance the fire safety materials industry.

For those seeking reliable fire-rated doors, our Class B fire doors exemplify the balance of durability, safety, and compliance. Trust Guangdun Door Industry Co., Ltd. to deliver top-tier fire door solutions tailored to your needs.