Dimensions (Width × Height, unit: mm): (1) Height 50 Series: 100×50, 150×50, 200×50, 300×50, 400×50 (2) Height 100 Series: 100×100, 150×100, 200×100, 300×100, 400×100, 500×100, 600×100, 800×100 (3) Height 150 Series: 200×150, 300×150, 400×150, 500×150, 600×150, 800×150, 1000×150 (4) Height 200 Series: 300×200, 400×200, 500×200, 600×200, 800×200, 1000×200, 1200×200 (5) Extra‑long Span / Special Widened Cable Tray for Power Plants: 1000×100, 1000×150, 1000×200, 1200×200 Plate Thickness (unit: mm): 1.0/1.2/1.5/2.0/2.5/3.0/3.5 Ⅰ. Product Definition: Fire-resistant large-span cable tray (GB model DJ-F series, subdivided into DJ-T-F ladder type, DJ-P-F tray type, and DJ-C-F channel type). The base material is made of thickened Q235B high-strength steel plates, with double-layer crimped side plates and multiple longitudinal reinforcing ribs on the bottom plate to enhance bending rigidity. After all straight through, bent through, and accessories are integrally molded, they are first hot-dip galvanized for corrosion protection and priming, and then sprayed with an expansive fire-resistant coating. The high-end, high-fire-resistant models adopt a double-layer steel plate clamped with aluminum silicate fire-resistant cotton composite structure. The product combines four core characteristics: ultra-large support span, heavy-load bearing capacity, long-term corrosion resistance, and fire-resistant and flame-retardant properties. It differs from conventional 2m standard fire-resistant trays: the standard single section is 6m, the conventional support span is 3/6m, and the reinforced customized model can reach 9~12m. The full-load deflection is strictly controlled to be ≤ span L/200, with a safety factor of ≥1.5. It is specifically designed for long-distance heavy-load fire-fighting wiring projects in open factories, road crossings, equipment crossings, tunnel pipe galleries, etc. II. Two Major Production Processes (1) Coated Standard Model (General Industrial Projects) – Enhanced Forming: The standard configuration for the panel is 2.0/2.5mm thickness, with a width of over 600mm, and 3.0~4.0mm thickened steel plates for spans of 6m; the side panels feature double-layer bending and edge rolling, while the bottom panel is integrally stamped with multiple continuous longitudinal reinforcement ribs; the ladder-type model is densified with 150mm ladder rungs to enhance load-bearing capacity; the 6m full panel is prefabricated without segmentation, and includes lifting, grounding, and connection holes, with a complete set of 6m long irregular-shaped parts provided. Base corrosion protection: Overall hot-dip galvanizing treatment, with a zinc layer thickness of ≥65μm, metallurgically bonded for rust prevention, suitable for outdoor, humid and corrosive environments. Fire-resistant coating: Multi-layered fire-resistant coatings are applied both internally and externally, and then dried and cured at high temperatures. The dry film thickness for F60 is ≥0.8mm, while for F90/F120, it is ≥1.2~1.5mm. Fireproofing principle: When exposed to fire at 200~300℃, the coating expands 5~10 times, forming a honeycomb-like dense carbonized thermal insulation layer. This layer isolates high temperatures and blocks heat conduction, ensuring that the cable remains continuously energized for a specified fire-resistant duration in case of a fire. II Double-layer composite high-fire-resistant type (specifically designed for tunnels, high-rise shafts, and pipe racks) features a double-layer steel plate structure for the side panels, with a high-density aluminum silicate refractory insulation cotton filled in the interlayer. This significantly enhances the thermal insulation performance, achieving a stable fire resistance limit of 90~120 minutes. It is suitable for enclosed, high-fire-resistant, and critical fire main lines for personnel evacuation. III. Complete set of supporting fireproof large-span accessories and straight-through accessories: Extended and thickened fireproof connecting pieces, Grade 8.8 fireproof galvanized bolts, grounding braided jumper wires; special-shaped turning pieces: 6m integrated horizontal bends, 45° bends, vertical up and down bends, tees, crosses, reducers; functional accessories: 6m long fireproof cover plates, metal divider plates, fireproof partition boards; support system: thickened load-bearing fireproof support arms, extended columns, seismic support and hangers (mandatory for tunnels, shafts, and substations). IV. Six Core Advantages 1. Ultra-large Support Span, Significantly Reducing Comprehensive Construction Cost Standards. For a 6m span, supports are only set up at both ends. Compared to a 2m ordinary fireproof cable tray, the amount of support arms and columns is reduced by more than 60%, reducing steel structure drilling and high-altitude lifting labor. In areas where the factory building spans equipment and roads, there is no need for intermediate columns, which does not obstruct the equipment passage. Although the unit price of the cable tray body is high, the total cost of supports + labor is reduced by more than 30%. 2. Thickened and reinforced structure, ultra-high heavy-duty, long-term non-deflection deformation double-layer crimping + multi-channel longitudinal reinforcement mechanical structure, 6m span rated uniform load 300~1000kg/m, full-load sag strictly controlled within specification limits; capable of carrying multi-circuit heavy-duty high-voltage fire protection cables, with no twisting or permanent deformation under long-term heavy load, and excellent seismic performance. 3. Hot-dip galvanizing + fire-resistant double-layer protection, suitable for harsh environments. The thick zinc layer on the bottom layer is resistant to rainwater, high salt spray, mild acids and alkalis, and high humidity, while the outer layer of expanded fire-resistant coating meets fire-resistant requirements for firefighting. Coastal power plants, chemical plants, wastewater treatment plants, and open-air pipe racks can simultaneously address the dual needs of corrosion prevention and fire resistance, with a service life of 20 to 30 years and no need for frequent maintenance in the later stages. 4. The six-meter ultra-long single section significantly enhances construction efficiency. With a single-piece integrated design, the number of splicing joints is reduced by 2/3, minimizing the risks of grounding discontinuities, smoke leakage through gaps, and water leakage. The speed of high-altitude long-distance through-lifting construction is increased by 50%, effectively shortening the project duration. 5. Three structural options are available, covering ladder, tray, and trough structures for full-scene fire protection wiring. It can accommodate both high-power fire protection power cables and enclosed shielded wiring for instruments and weak current communication. A single large-span system meets all the strong and weak current fire protection backbone wiring needs in the factory area. 6. The fire resistance is complete and uniform, successfully passing the fire safety inspection. The entire set of cable trays, covers, bends, and supports have undergone simultaneous fireproofing treatment, with no local shortcomings in fire resistance. We can provide a full set of third-party EI30/EI60/EI90/EI120 fire safety inspection reports, meeting the rigid requirements of fire safety regulations for high-rise buildings, tunnels, and civil air defense. Ⅴ. Applicable Scenarios: 1. Large steel structure factories and logistics warehouses: open roofs without columns, with dense and heavy-duty main fire protection high-voltage cables; 2. Chemical plants, oil refineries, wastewater treatment plants, coastal power plants, and offshore wind power platforms: high salt spray corrosion environment + dual requirements for fire resistance and fire protection; 3. Urban utility tunnels, highway tunnels, underground cable trenches, and overhead fire protection lines crossing roads in factory areas; 4. Substations, photovoltaic/wind farms, and metallurgical blast furnace areas: large amounts of 10kV high-voltage fire protection cables laid centrally; 5. Airports, high-speed rail stations, and large exhibition venues: high-altitude long-distance fire protection main cables with a height of over 8m; 6. Equipment-intensive factory areas, where cross-equipment fire protection wiring areas cannot be provided with additional support columns in the middle. VI. Key Points of Construction and Installation Specifications 1. Support arms, columns, and connecting bolts must all be equipped with thickened fire-resistant large-span specialized components. It is prohibited to mix ordinary thin fire-resistant components to avoid insufficient load-bearing capacity and electrochemical corrosion. 2. For the high-altitude lifting of six-meter-long trays, two-point synchronous lifting shall be adopted to prevent unilateral twisting and deformation. For spans >6m, intermediate load-bearing support columns must be added. 3. Each section of the tray along the entire line shall be installed with grounding braided jumper wires. Additional repeated grounding shall be provided for tunnels, high-rise shafts, and chemical substations to ensure continuous equipotential conduction. 4. For the laying of strong and weak electrical cables in the same tray/trough with large spans, metal dividers must be installed for complete isolation. For outdoor, dusty, pipe racks, and shafts, 6m-long fireproof cover plates shall be provided throughout. 5. For spans of six meters and above, as well as high-voltage fire protection main lines, seismic support hangers shall be provided according to specifications. 6. Immediately apply fireproof patching paste to the cut, ground, and drilled sections during on-site cutting, grinding, and drilling to fully restore the fireproof and thermal insulation layer. 7. After installation, the full-load deflection of the tray shall be reviewed. The sagging amount shall not exceed 1/200 of the span. If the standard is exceeded, support points shall be densified. 8. Special fireproof sealing materials shall be provided for trays passing through walls and floor holes to block the longitudinal spread of flames and smoke along the tray.