Spiral duct installation is a critical phase, with the main work of ventilation and air conditioning engineering focusing on duct installation. Therefore, it is essential to master the technical characteristics of multifunctional silencer pipes, familiarize with construction drawings, understand the correlation between this trade and civil engineering and other specialized trades, verify the elevation, axis, reserved holes, and embedded components of the duct system to ensure they meet installation conditions. Stock up on various auxiliary materials for installation, prepare lifting equipment and other tools for installation, and mark and position the duct system.
The duct assembly process involves transporting finished or prefabricated ducts to the installation site, conducting on-site inspections and reviews, and then arranging them by number. Once the dimensions and angles of all parts of the duct system are confirmed to be accurate, the assembly work begins. Connections between duct sections are made using flanges, with a requirement for airtight interfaces to prevent any leakage.
The length of the duct to be hoisted should be determined based on the building conditions, the wall thickness of the duct, the hoisting method, and the equipment available. The assembled duct can use the flanges at both ends as reference points, with the middle flange as the measurement point, to check if the connection is straight. Adjustments should be made if there are significant deviations. Before hoisting, inspect the supports and hangers for the duct, the hoisting equipment, and the chosen support and hoisting points for correctness and stability. Thoroughly check before lifting, ensuring that the rod, pulleys, ropes, etc., are securely fastened, the ties are reliable, and all unsafe factors in the hoisting area are cleared. During lifting, first perform a trial lift. When the duct is 200-300mm off the ground, stop the lift and conduct a comprehensive check of the hoisting equipment. Confirm that everything is correct before continuing to lift to the desired height. Only after the duct is securely fastened to the supports and hangers should the ropes be untied and the hoisting equipment removed.
After the horizontal main pipe is leveled, aligned, and securely fastened to supports and hangers, the installation of branch pipes can proceed. The vertical pipes can be installed before the horizontal main pipe is set up. The spacing between supports should not exceed 4 meters, and each vertical pipe should have at least two fastening pieces. For horizontal duct installation, the allowable deviation in levelness should not exceed 3 millimeters per meter, with a total deviation not to exceed 20 millimeters. For vertical duct installation, the allowable deviation in verticality should not exceed 2 millimeters per meter, with a total deviation not to exceed 20 millimeters.
