1. Fireproof bridge is mainly used for laying indoor and outdoor overhead cable trench and tunnel construction, such as power cable, control cable and lighting wiring within 10kV. The fireproof bridge is mainly composed of glass fiber reinforced material, inorganic adhesive composite fireproof board, metal skeleton composite material and other fireproof substrates, and the outer layer is coated with fireproof coating. The fire-proof bridge is not easy to burn in case of fire to prevent the spread of fire. The fireproof bridge has excellent fire prevention and fire resistance practical effect, and has the characteristics of fire prevention, oil resistance, corrosion resistance, non toxicity, convenient overall installation and so on. The fireproof coating has the characteristics of thin coating, high fire resistance and strong adhesion.

2.镀锌电缆桥架主要用于潮湿和寒冷的、腐蚀环境。根据生产工艺的不同，可分为热镀锌和电镀锌(即冷镀锌)两种。此外，它们在过程中略有不同。

2. Galvanized cable tray is mainly used in humid, cold and corrosive environment. According to different production processes, it can be divided into hot galvanizing and electro galvanizing (i.e. cold galvanizing). In addition, they are slightly different in the process.

热镀锌电缆桥架的工艺流程：将钢制零件或铸件浸入熔融锌液中，在其表面形成锌铁合金或锌及锌铁合金镀层的工艺流程和方式。

Process flow of hot-dip galvanized cable tray: immerse steel parts or castings in molten zinc to form zinc iron alloy or zinc and zinc iron alloy coating on its surface.

冷镀锌电缆桥架工艺流程：钢材表面化学清洗处理后，放入含氧化锌的电镀液中。一个DC电极与钢相连，另一个与电镀液中的锌板相连。通电后，锌以分子状态被置换到钢的表面。如果加入光亮剂钝化，会呈现云状光亮涂层。

Process flow of cold galvanized cable tray: after chemical cleaning of steel surface, put it into electroplating solution containing zinc oxide. One DC electrode is connected to the steel and the other is connected to the zinc plate in the electroplating solution. After energization, zinc is replaced to the surface of steel in molecular state. If the brightener is added for passivation, the cloud like bright coating will appear.

电镀锌应用于钢结构的防锈效果通常不是很好，主要是因为镀锌量达不到，镀锌不对称，一般两三年左右就会生锈，质量差的暴露在湿冷环境中十几天就会生锈。热浸镀锌层厚，耐腐蚀性强。冷镀锌层比热镀锌层光亮，但较薄，防锈能力弱。

The antirust effect of electro galvanizing applied to steel structures is usually not very good, mainly because the amount of galvanizing is not enough and the galvanizing is asymmetric. Generally, it will rust in about two or three years, and the poor quality will rust in more than ten days after exposure to wet and cold environment. The hot-dip galvanized layer is thick and has strong corrosion resistance. The cold galvanized layer is brighter than the hot-dip galvanized layer, but it is thinner and has weak anti rust ability.