A Double Leaf Fire Rated Door is a double-leaf fire door system composed of two door panels of unequal width, primarily used in building areas requiring high efficiency in personnel traffic, fire integrity, and space separation. These doors typically use steel plates as the main structural material, forming a stable door core through multi-layer composite filling and overall compression molding. Under fire conditions, they can maintain structural integrity and fire resistance for a specified period. The double-door structure significantly increases the passage width compared to single doors, suitable for stretchers, equipment, or multiple people passing through simultaneously. The unequal width design allows for opening only the main door panel in daily use, reducing energy consumption and management costs. As an important component of building fire protection systems, Double Leaf Fire Rated Doors usually form a complete system with the door frame, door closer, lock body, and observation window, meeting the regulatory requirements for building fire compartments, evacuation routes, and functional space isolation. Their core design focuses not on aesthetic appearance, but on consistently and reliably performing the fire separation function under high temperature, smoke, and pressure conditions, and remaining consistent with the overall building fire safety strategy.

1. Structural Stability

The Double Leaf Fire Rated Door features a monolithic steel plate door leaf structure, with common steel plate thicknesses ranging from 0.8 to 1.2 millimeters.  Combined with multi-point welding and reinforcing ribs, it maintains door leaf flatness even in high-temperature environments. Standard fire resistance tests show that structural deformation is controlled to within 5 millimeters in environments above 800 degrees Celsius, effectively preventing door leaf failure and ensuring continuous compliance with fire resistance integrity standards, meeting the structural stability requirements for fire-rated doors in buildings.

2. Fire Resistance Performance

This Double Leaf Fire Rated Door typically achieves a 60-minute or 90-minute fire resistance rating.  During standard fire furnace tests, the average temperature rise on the non-fire side of the door does not exceed 140 degrees Celsius, and the maximum single-point temperature rise does not exceed 180 degrees Celsius. Through the thermal resistance combination of the steel plate and fire-resistant core material, it effectively blocks the transmission of flames and high temperatures, ensuring that the fire compartment is not penetrated within the specified time.

3. Closing Control

The door system can be equipped with a hydraulic door closer, commonly with closing force levels of EN3 to EN5, and a closing speed controlled within 3 to 7 seconds. Even under frequent opening conditions, it ensures that the door leaf automatically resets and closes completely, reducing the risk of fire failure due to human negligence. This feature gives the Double Leaf Fire Rated Door continuous and reliable active closing capability in fire safety strategies.

4. Integrated Observation

The door leaf can integrate a fire-resistant observation window, commonly using fire-resistant glass with a thickness of 20 to 25 millimeters.  During fire resistance tests, it can achieve the same fire resistance integrity as the door body for over 60 minutes. The observation window typically has a light transmittance of greater than 70%, providing visual passage judgment without compromising fire resistance performance, helping to improve safety management efficiency during use, and maintaining the consistency of the overall fire protection system.

5. Sealing Control

The door body can be equipped with high-temperature resistant sealing strips, commonly with an expansion ratio of 5 to 10 times, which automatically expand at temperatures above 180 degrees Celsius to form a smoke barrier. Smoke leakage tests show that the leakage rate is controlled to no more than 3 cubic meters per minute per square meter, effectively limiting smoke diffusion. This sealing system allows the Double Leaf Fire Rated Door to provide both smoke and fire isolation from the initial stages of a fire.

1. Medical Passageways

In main hospital corridors or at the junctions of functional zones, Double Leaf Fire Rated Doors can accommodate the wide passage requirements for stretchers and medical equipment. The clear opening width of double doors typically exceeds 1000 mm, reducing resistance to the movement of personnel and equipment. Stable door closure helps to quickly create fire compartments in the event of a fire, ensuring the continuity of evacuation routes in medical areas and meeting the fire compartment design requirements of medical buildings.

2. Laboratory Spaces

Laboratory areas have high requirements for safety isolation, and Double Leaf Fire Rated Doors can be used for fire separation between hazardous experimental areas and public corridors. The steel door body's impact resistance can withstand the mechanical loads generated by daily trolley and equipment movement, and it is not easily deformed during long-term use. Stable fire separation capabilities help reduce the risk of accident spread and improve the overall safety level of the experimental environment.

3. Clean Rooms

In the functional separation of clean rooms, these fire-rated doors can work in conjunction with the building's fire protection and clean room management systems. The door surface coating can withstand more than 5000 cycles of cleaning with cleaning agents, maintaining surface integrity over the long term. As a Double Leaf Fire Rated Door, its fire resistance and space isolation functions work in parallel, helping to maintain the safe operation and management order of the clean room.

4. Public Buildings

Large public buildings often have fire compartment nodes, and double-leaf fire doors are suitable for areas with high pedestrian traffic. The double-door structure can disperse traffic pressure during peak hours, while the unequal width design reduces the opening area during off-peak hours. The stable fire barrier capability makes Double Leaf Fire Rated Doors a key component in public building fire protection systems.

5. Technical Rooms

At the entrances of technical spaces such as machine rooms and electrical rooms, these fire-rated doors can be used as fire separation and daily maintenance access. The steel plate door body provides physical protection for internal equipment and delays the spread of fire under fire conditions. Through reasonable configuration, Double Leaf Fire Rated Doors can effectively support the safe operation and risk control of building equipment areas.

Daily cleaning:

Use a soft dry or slightly damp cloth to wipe the surface of the Double Leaf Fire Rated Door. Avoid using detergents containing corrosive chemicals to avoid damaging the surface coating. The door frame and hardware should also be cleaned regularly to ensure that there is no dust and stains accumulated on the surface to maintain the overall appearance and good working condition of the door.

Check the door closer:

Check the operation of the Double Leaf Fire Rated Door door closer regularly to ensure that it can work properly. Check whether the mounting bolts of the door closer are loose. If they are loose, tighten them in time. At the same time, check whether the oil level of the door closer is sufficient. If necessary, add special lubricating oil according to the requirements of the product manual to ensure the service life and performance of the door closer.

Check the lock:

Check the flexibility and reliability of the Double Leaf Fire Rated Door lock regularly to ensure that the lock tongue can be retracted and retracted normally and the lock core rotates smoothly. If the lock is found to be stuck or difficult to open, add an appropriate amount of lubricating oil in time, or contact a professional for repair. At the same time, check whether the lock is installed firmly regularly to prevent the normal use of the lock from being affected by looseness.

Check the door frame and hardware:

Check whether the Double Leaf Fire Rated Door door frame is firmly installed and whether it is loose or deformed. For hardware, such as hinges and handles, check whether they are loose or damaged. If there is a problem, replace or repair it in time. Lubricate and maintain the hardware regularly to extend its service life and ensure the normal opening and closing of the door.

Check the fire seal:

The fire seal is an important fireproof component of the Double Leaf Fire Rated Door. Check it regularly to see if it is intact. If the seal is found to be aging, deformed or falling off, replace it with a new one in time to ensure the fireproof performance of the door. At the same time, when installing the seal, ensure that it fits tightly with the door frame and door leaf without any gap.

Check the overall structure regularly:

Check the overall structure of the Double Leaf Fire Rated Door regularly, including the door leaf, door frame, filling material, etc. Check whether the door leaf is deformed or damaged, whether the door frame is firm, and whether the filling material is loose. If any problems are found, they should be repaired or replaced in time to ensure the fire resistance and overall stability of the door, providing reliable protection for the safety of the building.