Technical specifications for the installation of air duct supports and hangers and key points for air duct connection

1. Installation of supports and hangers 1. The supports and hangers should be installed symmetrically along the center line of the duct, and the hangers should be fixed safely and reliably. The welded parts should be painted. 2. When installing the vertical pipe clamp, the top pipe clamp should be fixed first, from top to bottom. 3. The duct is long. When installing it in a row of brackets, first install the two ends, and use the brackets at both ends as the reference. The middle brackets are installed by the wire drawing method. 4. When installing horizontally, the long side is ≤400 mm and the spacing is ≤4 meters; the long side is >400, and the spacing is ≤3 meters; the supports and hangers for spiral ducts are 5 meters and 3.75 meters respectively. 5. When the length of the main and trunk ducts exceeds 20 meters, fixed points should be set to prevent swinging, and each system should not be less than 1. When the duct is installed vertically, the spacing between the supports and hangers is ≤4 meters, and a single one has at least two fixed points. 6. The supports and hangers shall not be set at the air outlet, valve, inspection door and automatic control mechanism, and the distance from the air outlet should be greater than 200 mm. 7. The corner of the clamp bracket should be straight, the arc of the circular air duct should be uniform, and the clamp should be close to and hold the air duct tightly. 2. Connection of air duct 1. The flange sealing gasket should be made of airtight and elastic materials. The flange gasket should minimize the joints. The joint form should be stepped, and the joints should be coated with sealant. 2. When connecting the flanges, first pad the gasket, then align the two flanges, put on a few bolts and tighten the nuts without tightening them, then use a sharp punch to insert it into the screw holes that are not bolted, pry the two screw holes straight, and tighten the bolts until all the bolts are put on. When tightening the bolts, they should be tightened crosswise and evenly. 3. After the air duct is connected, check whether the air duct connection is straight based on the flanges at both ends. 4. The bolts for the flange connection of stainless steel air ducts should be made of stainless steel of the same material. If ordinary ones are used, they should be sprayed with paint. 5. Galvanized bolts are used for the connection of aluminum plate air ducts, and galvanized washers are placed on both sides of the flange. 6. For the flange connection of non-metallic ducts, the end faces of the two flanges should be parallel and tight, and galvanized washers should be added on both sides of the flange bolts. III. Installation of ducts 1. Technical requirements: the horizontality of the exposed installation is ≤3mm per meter, and the total deviation is ≤20mm; the verticality is ≤2mm per meter, and the total deviation is ≤20mm; for concealed installation, the position should be correct and there should be no obvious deviation. 2. Installation sequence: first the main pipe and then the branch pipe. Installation method: determined according to the actual situation. It can be connected to a certain length on the ground, and then hoisted as a whole. Generally, it can be extended to about 10-12 meters. The duct can be hoisted to the bracket with a chain or a lift (for heavier ducts), or the duct can be placed on the bracket section by section and connected section by section. 3. When the duct passes through the fireproof and explosion-proof wall or floor that needs to be closed, a pre-buried pipe or protective sleeve should be set, and the thickness of the steel plate should not be less than 1.6mm. Between the duct and the protective sleeve, a non-combustible and harmless flexible material should be used to seal. 4. The joints of composite material air ducts should be firm, without holes or cracks. After the air duct system is installed, it should be tested for tightness according to the system type.