Let me explain how the quality of explosion-proof doors is ensured.

　　Explosion-proof doors are moisture- and water-resistant; those with a closed-cell porosity exceeding 90% are hydrophobic materials that do not increase their thermal conductivity upon moisture absorption and are completely leak-proof. Polyurethane is a flammable, self-extinguishing material formulated with flame retardants, with a softening point of over 250°C—decomposing only under extreme high temperatures. Moreover, during combustion, polyurethane forms a carbonized layer on the foam surface, which helps to isolate the foam and effectively inhibits flame spread. Additionally, polyurethane does not emit harmful gases at elevated temperatures. Chemical explosion-proof doors exhibit low thermal conductivity and excellent thermal performance: when the door density is 35–40 kg/m³, the thermal conductivity is only 0.018–0.024 W/(m·K), roughly half that of EPS, one of today’s most common insulation materials. Upon selecting a manufacturer for installation, the manufacturer is required to perform secondary design work. We maintain our own construction teams for both explosion-proof doors and windows, meticulously attending to every detail—from receipt of the drawings to material cutting and fabrication. The panel material used in explosion-proof doors can withstand fire for more than four hours at 1,000°C, meeting stringent non-combustibility standards. The new-generation explosion-proof doors address the shortcomings of older models—unreliable sealing and susceptibility to weather conditions—thereby fully satisfying the design requirements for such doors. Fire-rated doors are designed in accordance with acoustic principles and relevant standards, ensuring compliance with both fire-resistance requirements for public spaces and sound-insulation needs in everyday use. These doors feature a double-layer composite structure made of galvanized steel (or stainless steel), with a porous, fire-resistant, sound-absorbing material filling the core; the door thickness ranges from 60 to 80 mm.

　　Explosion-proof doors are designed to withstand pressures within this range, thereby providing the necessary protective function to prevent casualties and property damage. Following an incident, the door can continue to operate normally as long as the applied force does not exceed the preset threshold; however, when the critical force is reached, the door will deform while still maintaining its structural integrity, effectively preventing personnel from being trapped or confined. The door also features essential airtight isolation to inhibit direct convective exchange between the isolated space and the external atmosphere, thus minimizing contamination of the protected enclosure from the outside environment. In addition, explosion-proof doors are equipped with self-closing and emergency egress functions, making them an integral safety feature.

　　What aspects should be paid attention to in the daily maintenance of explosion-proof doors?

　　The material and thickness of the blast-resistant door formwork shall not be altered arbitrarily; design standards must be strictly adhered to. For blast-resistant doors manufactured by qualified producers, except for the aluminum panel beneath the groove, integral partitioning is prohibited; only single-lock joints are permitted, and joint locations must comply with design requirements. Additionally, the outer sides of the bolt holes around the blast-resistant door shall be countersunk to reduce the opening resistance of the blast-resistant door within the blast-resistant window.

　　In short, cast-aluminum explosion-proof doors can indeed deliver true explosion-proof performance, offering design solutions that are more attuned to everyday life, providing more comprehensive protection for our daily routines, and enabling us to enjoy a happier, more secure lifestyle.

　　That’s all for today’s briefing. If you’re looking to customize or procure explosion-proof doors, please feel free to contact me.