What are the fireproof spraying techniques for cable tray and the standard thickness of the coating?

Cable trays are classified by material into steel, aluminum alloy, stainless steel, etc.

The surface treatment of cable tray products includes cold galvanizing, hot-dip galvanizing, spray coating, fireproof paint, baking paint, etc. It is divided into tray body, accessories, spare parts, supports and hangers, etc. according to the usage part.

Below, the editor will introduce the fireproof spraying process and coating standard thickness to everyone.

The installation of cable trays should be based on electrical construction drawings, and the direction of cable trays should be measured. Standard products and factory prefabricated components should be used. The cable tray should be segmented reasonably, and the connection position between the two sections should not pass through walls or cross floor holes.

Cable trays need to be covered in indoor and outdoor environments where dust, combustible dust, or sun protection is prone to accumulate. In outdoor environments where it often rains, ridges and drainage holes should be installed to prevent water accumulation in cable trays.

Fire resistant cable trays are divided into three fire resistance levels: NI~NIII. The time required to maintain normal cable operation is 1 hour for NI, 45 minutes for NII, and 30 minutes for NIII. The above are the fire resistance time standards for fire-resistant cable trays.

When laying fire-resistant cable trays horizontally with heat pipes without insulation measures, the parallel spacing should be at least 1000mm, and the minimum spacing for cross laying should be 500mm. The minimum spacing for cross laying fire-resistant cable trays with heat pipes with insulation measures should be 300mm, and the minimum spacing for horizontal laying should be 500mm.

The fireproof spraying process for cable trays includes spraying fireproof coatings and spraying fireproof thermosetting powders. According to the requirements of the bridge tray standard for fire protection layer, the standard thickness of the coating should be greater than or equal to 60um. If the technical standards and specifications for bridge engineering specify the thickness of the coating, it should be sprayed and accepted according to the specified standard thickness.