The installation steps and precautions for cable trays are detailed as follows:
Installation steps:
Positioning and laying out: Determine the starting and ending positions according to the construction drawing, mark the direction along the drawing, find horizontal, vertical, and curved lines, use powder line bags or draw lines along the bridge direction to snap or draw lines on walls, ceilings, floors, beams, slabs, columns, etc., and draw the positions of supports, hangers, and brackets evenly across the span.
Pre embedded iron parts or expansion bolts:
The self-made processing of embedded iron parts should not be less than 120mm × 80mm × 6mm, and the diameter of the anchored round steel should not be less than 10mm.
Closely cooperate with the construction of civil engineering structures, tightly adhere the embedded iron parts to the formwork, and fix the anchoring round steel to the steel bars inside the structure by binding or welding; After the concrete formwork is removed, the embedded iron parts should be exposed on the surface, and the brackets, hangers or brackets should be welded on top for fixation.
Installation of supports and hangers:
According to the principle of fixing every 1.5 meters, mark the installation hole positions on the ceiling or wall, drill holes, and knock in expansion pipes to tighten them. Install a set of hangers at the other end of the straight section using the same method.
Use nylon wire to pull through the installation cable trays of the front and rear hangers, and tighten the nylon wire tightly. Use nylon thread as a reference line to adjust the suspension bracket installed in the middle.
The distance between the fixed positions of hangers and cable trays at the beginning, branches, corners, joints, and the support and hanger at the inlet and outlet boxes shall not exceed 0.5 meters.
Detailed introduction of cable tray installation steps, what issues should be noted?
Installation of steel trough:
The connection of the trunking should be continuous without interruption, and each section of the trunking should have at least two fixed points. There should be fixed points at corners, branches, and ends, and they should be tightly attached to the wall for fixation.
The connection of the straight section of the steel groove should be made using a connecting plate, with a half round head screw threaded from the inside out and fastened with a flat washer and spring washer nut. The gap at the connection should be tight and level. The groove cover should be complete, flat, and free of warping.
The screws or other fasteners used to fix or connect cable trays should have their ends smoothly connected to the inner surface of the cable tray after tightening.
When connecting corners and branches of steel troughs, flexible connections such as bends, two-way connections, three-way connections, and four-way connections should be used, and sealing plates should be installed at the end of the steel trough.
Notes:
Appearance inspection: When transporting the bridge to the construction site, relevant documents such as the factory certificate of conformity, provincial and municipal quality supervision reports, and technical appraisal documents of the product should be submitted. For hot-dip galvanized cable trays, the surface should be uniform and free from phenomena such as overburning, hanging dust, and incomplete zinc plating. The surface of the electrostatic spray painted bridge should be smooth and flat, without bubbles, peeling, or distortion. The hairless spine bridge should be welded evenly on the surface, without defects such as solder leaks, cracks, burn through, etc.
Installation position: When laying the bridge horizontally, the height should generally not be less than 2.5m. When laying multiple layers, heat dissipation and maintenance space should be reserved, and the clear distance should comply with relevant regulations.
Installation of supports and hangers: The steel used for supports and hangers should be straight and without significant distortion. The installation of supports and hangers should comply with the relevant technical standards for horizontal laying. The support span should be 1.5-3m for vertical laying, and the fixed spacing should not exceed 2m. The height difference between two adjacent bridge supports should not differ by 10mm, and the vertical centerline deviation should not exceed 20mm.
Environmental factors: Cable trays are not suitable for parallel installation below pipelines transporting corrosive liquids or above pipelines transporting corrosive gases. When the bridge is built parallel to the heating pipeline, it should not be less than 500mm when there is insulation material for the heating pipeline, and not less than 1000mm when there is no insulation material. The bridge is not suitable for installation on the parallel surface above the heating pipeline. When it cannot be prevented from being installed on the parallel surface above the heating pipeline, it should not be less than 1000mm, and effective insulation measures should be taken in between.
Following the above steps and precautions can ensure the safety, stability, and effective installation of cable trays.