What type of structure does a fireproof cable tray have

Fireproof cable trays are designed with fire-resistant cores, reinforced structures, and protective coatings to ensure cable safety and operational reliability under high-temperature conditions.Core Structure and MaterialsFireproof cable trays typically use fire-resistant boards or epoxy-based intumescent coatings as the primary protective layer. These materials form a dense, insulating char under high temperatures, significantly reducing heat transfer to the cables inside, and preventing flame propagation . The core fire-resistant layer is usually 5–12 mm thick, non-combustible, and has low thermal conductivity, providing protection for 60 minutes or more depending on the fire rating . To enhance structural stability, many designs incorporate internal metal reinforcement plates or ribs. These reinforcements prevent deformation, maintain long-span installation stability, and improve load-bearing capacity, ensuring the tray can support heavy cable loads even under fire conditions . Thin-walled steel with reinforcing ribs can reduce weight by 20–40% while increasing bending stiffness .Fire Protection CoatingsAdditional fireproofing can be achieved with fire protection coatings or tapes, such as FLAMMOTECT-A or DG-CR 0.7, which provide a protective shield against flames, UV radiation, moisture, and chemicals . These coatings ensure that cables remain functional during a fire, supporting critical power and communication systems.Design ConsiderationsTray Shape: Arc-shaped trays are used for curved installations, reducing cable stress and improving aesthetics .Ventilation: Integrated ventilation grilles prevent heat accumulation, reducing cable aging and maintaining system reliability .Material Selection: Indoor trays often use painted steel or galvanized steel, while outdoor or corrosive environments may require stainless steel, aluminum alloy, or fiberglass-reinforced plastic .Firestopping and InstallationFireproof cable trays must comply with firestopping standards at wall or slab penetrations. Openings should be sealed with fire-rated boards, firestop packs, mastic, or mineral wool, ensuring no visible cracks or voids. Large openings may require a fire-resistant backing plate, and gaps around cables should not exceed 1 cm² with a minimum packing thickness of 24 cm . Proper layout and positioning facilitate maintenance and ensure reliable fire protection.ApplicationsThese fireproof cable trays are widely used in nuclear power facilities, industrial plants, high-rise buildings, hospitals, and offshore installations, where fire safety and operational continuity are critical . By combining fire-resistant cores, structural reinforcement, protective coatings, and proper firestopping, fireproof cable trays provide a robust solution for maintaining cable integrity and safety in high-risk environments.