The coating surface of the hot-dip galvanized tray of the air insulated bridge shall be uniform, free of defects such as burr, overburning, ash hanging, scar, local galvanizing, etc., and shall not have zinc nodules that affect the installation, and the coating of the thread shall be smooth; Bolted connections shall be screwed in. The painted bridge shall be flat, smooth, uniform, without peeling and bubbles. The weld surface of the bridge shall be uniform, and there shall be no defects such as missed welding, crack, slag inclusion, burnthrough, crater, etc.
The specifications of various bends and accessories shall be suitable for the engineering layout conditions and shall be matched with the tray and ladder; The specifications of supports and hangers shall be selected according to the specifications of trays and ladders, and shall meet the load requirements. Determine the position from the beginning to the end according to the construction drawing, mark the direction along the drawing, find out the horizontal, vertical, and bending, use chalk bags or draw lines along the bridge direction to snap or draw lines on the wall, ceiling, floor, beam, plate, column, etc., and draw the positions of supports, hangers, and brackets evenly.
1. The steel used for the installation of supports and hangers of air insulated bridge shall be flat and straight without significant distortion. The length deviation after blanking shall be within 3mm, and the notch shall be free of curling and burr.
2. The steel support and hanger of the air insulated bridge shall be welded firmly without significant deformation. The support and iron parts with a thickness of more than 4mm shall be beveled before welding. The weld shall be uniform and flat. The length of the weld shall meet the requirements, and there shall be no cracks, undercuts, air holes, dents, missed welding and other defects.
3. The air insulated bridge shall select the corresponding expansion bolts and drill bits according to the load borne by the support; The length of the selected drill bit should be greater than the length of the expansion casing, and the depth of the hole should be based on the standard after the casing is completely buried in the wall or roof, and the surface should be flush. The debris in the hole shall be cleaned first, and then the expansion bolt shall be knocked into the hole with a wooden hammer. The casing shall be flush with the building surface, and the bolt end shall be exposed. The screw thread of the bolt shall not be damaged when knocking. After embedding the bolts, use nuts and corresponding washers to fix the bracket or hanger directly on the metal expansion bolts.