Long-span cable trays Long-span cable trays can be divided into stepped, tray, and trough. The cascade bus bridge has good ventilation performance, is not dustproof and may interfere. The surface treatment of the tray-type cable tray can be divided into three types: galvanized, electrostatic sprayed and hot-dip galvanized according to user needs. It can be treated as a special anti-corrosion in heavy corrosive environment. The trough type and tray type cable tray have dustproof and anti-interference performance. The trough cable tray is a fully enclosed cable tray with a cover plate and using the smallest number of connecting bolts. It is most suitable for laying computer cables, communication cables, thermocouple cables, and control cables for other highly sensitive systems. It has very good effects on shielding interference of control cables and protection of cables in highly corrosive environments.