The GJB2805B-2021 standard specifies the following technical requirements for ventilation doors (ventilation airtight doors, airtight ventilation windows, etc.):

Performance Requirements

• Airtightness Performance: The airtightness of ventilation doors must meet the Grade 8 requirement of the GB/T7106-2019 standard, meaning that under a pressure of 10Pa, the air infiltration rate per unit area should be ≤0.5m3/(m2·h).

• Anti-Theft Performance: The anti-theft rating of ventilation doors should be Level 1, with an overall anti-destruction capability of no less than 25 minutes.

Materials and Structure

• Door Body Material: The main frame of the ventilation door should be made of steel profiles with sufficient strength and reliable welding. Under the action of a single person using ordinary tools, the welding points should not crack, and the local plastic deformation of the frame should not exceed 2cm.

• Grille Design: If the ventilation door is equipped with a grille, it should be made of 16x16mm square steel profiles, with a single grid size not exceeding 250x60mm or 120x130mm, and welded using vertical-long, horizontal-short staggered and evenly distributed welding.

• Door Sealing Plate: Use 4mm Q235 steel plate profiles with sufficient strength and toughness, ensuring reliable welding without cracking at the welding points.

• Anti-Rodent Mesh: Use 10x10x1.5mm galvanized steel mesh or stainless steel mesh profiles.

Ventilation and Airtight Functions

• Ventilation Structure: The ventilation door can be designed with adjustable louvers or other forms. The blades are inclined at 45°, and an internal stainless steel insect screen is installed. When closed, the louvers are driven by manual or electric devices to close, achieving complete airtightness with the help of sealing strips.

• Airtight Design: The sealing structure of the ventilation door may adopt a multi-layer sealing system, such as double or triple sealing strips, placed at the contact surfaces of the door frame and door leaf, as well as the edges of the ventilation opening moving parts, forming a環(huán)形密封腔 (annular sealing cavity) to ensure no air infiltration when closed. The edges of the door leaf can be machined with grooves to embed elastic sealing strips,配合門框的凸臺設(shè)計 (matching the raised design of the door frame) to form a "mortise-and-tenon" seal, enhancing the airtightness等級 (grade).

Locks and Fixing

• Bolt Requirements: Use ?25 Q235 round steel profiles with a cross-sectional area of no less than 490mm2 and an effective extension length of no less than 30mm. The bolt should function in three directions: top, bottom, and opening side. A lockable bolt should be installed on the inner side of the door.

• Padlock Requirements: The door padlock should be installed in a concealed location on the inner side of the door. Locking and unlocking are performed through a lock hole on the ventilation door. The lock hole size should not exceed 100mmx150mm, with the nearest distance to the padlock center being no less than 250mm, and a lockable small door should be installed. Within a 200mm radius around the padlock, an additional protective steel plate with a thickness of no less than 3mm should be installed.

Installation Requirements

• Fixing Method: The door frame should be fixed to the wall using expansion bolts ≥12mm (spacing ≤500mm) or by welding to預(yù)埋鋼板 (embedded steel plates), ensuring a牢固連接 (firm connection) between the door body and the building structure to prevent overall disassembly.

• Sealing Treatment: The gap between the door frame and the wall should be filled with fire-resistant sealant,兼顧氣密與防火性能 (balancing both airtightness and fire resistance).