The coating surface of hot-dip galvanized tray tray of air insulated tray shall be uniform, free of defects such as burr, over burning, ash hanging, scar and local galvanization, without zinc tumor affecting installation, and the coating of thread shall be smooth; Bolted connections shall be screwed in. The spraying bridge shall be flat, smooth, uniform, free of peeling and bubbles.
The weld surface of the bridge shall be uniform and free of defects such as missing welding, crack, slag inclusion, burn through and arc pit. The specifications of various bends and accessories shall be suitable for the engineering layout conditions and shall be matched with pallets and ladders; The specifications of supports and hangers shall be configured according to the specifications of trays and ladders, and shall meet the requirements of load. Determine the position from the beginning to the end according to the construction drawing, mark the direction along the drawing, find the horizontal, vertical and curved connection, snap lines or draw lines along the bridge direction on the walls, ceilings, floors, beams, plates, columns, etc., and draw the positions of supports, hoists and brackets with uniform span.
1. The steel used for the installation of supports and hangers of air insulated bridge shall be straight without significant distortion. After blanking, the length deviation shall be within 3mm, and the notch shall be free of curling and burr.
2. The steel support and hanger of air insulated bridge shall be welded firmly without significant deformation. Before welding, the support and iron parts with a thickness of more than 4mm shall be beveled, the weld shall be uniform and flat, the weld length shall meet the requirements, and there shall be no defects such as crack, undercut, air hole depression and missing welding.
3. The air insulated bridge shall select the corresponding expansion bolt and drill bit according to the load borne by the support; The length of the selected drill bit shall be greater than the length of the expansion casing. The drilling depth shall be based on the standard after all the casing is embedded in the wall or roof, and the surface shall be flush. The debris in the drilled hole shall be removed first, and then the expansion bolt shall be knocked into the hole with a wooden hammer. It shall be ensured that the casing is flush with the building surface, the bolt end is exposed, and the screw thread of the bolt shall not be damaged during knocking. After embedding the bolts, fix the supports or hangers directly on the metal expansion bolts with nuts and corresponding washers.