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Specification for the manufacture and installation of phenolic air ducts

Specification for the manufacture and installation of phenolic air ducts


Specification for the manufacture and installation of phenolic air ducts

1. The side length of the rectangular duct made of phenolic aluminum foil composite duct should be 120≦L≦3000, and the ratio of the long side to the short side should not be greater than 4:1.

When making the air duct, in order to ensure the strength of the air duct after it is made, one side of the adhesive part should be kept with 20mm aluminum foil for edge protection during cutting.

The surface of the air duct should be flat, the two ends should be parallel, and there should be no obvious deformation, blistering, and no damage to the aluminum foil.

2. F-type flanges should be used for the connection of air ducts. Adhesive should be applied to the splicing part. Attention should be paid to the splicing of air ducts: positioning first and then pasting. The bonding surface should be clean. After the glue is dry to a certain extent, splicing, align the joints, ensure that all sides are vertical, use a spatula to press and stick firmly, and apply sealant to the inner seams of the air duct to seal to prevent air from contacting the insulation foam.

3. There is at least a 25mm wide lap joint with the adjacent surface, and be careful not to create wrinkles when tightening. Where there are large curved surfaces or gaps, it can be sealed with glass glue. When pasting the aluminum foil tape, the two sides in contact with the tape should be clean and smooth. Flatten the tape with a spatula to squeeze out the air. The bonding at the seam should be tight and firm.

4. Where the outer aluminum skin is cut off, it must be sealed with pressure-sensitive tape, and the surface of the part to be bonded must be kept clean and dry. When the flange is broken, add a short pipe. When sealing, use a scribe ruler to get the tape to adhere neatly, and use a spatula to make sure all air under the tape is squeezed out.

5. All seams must be in one line.

The duct corner reinforcement is to paste galvanized right-angle gaskets with a thickness of more than 0.75mm on the four corners of the duct. The width of the right-angle gasket is equal to the thickness of the duct plate, and the side length is not less than 55mm.

The connection between the main air duct and the branch air duct: the direct opening on the main air duct to connect the branch air duct can use a 90° connector or other special connector, and sealant should be applied to the four corners of the connector.

For the connection between the main air duct and the flexible air duct, attention should be paid to placing the annular stop on the composite board, and then pulling the edge to fix it.

phenolic air ducts

6. Phenolic air duct hoisting:

1) The support and hanger of the extra-wide special air duct shall be specified according to the design or current specifications.

2) The blanking of the support and hanger is machined, and the gas welding cutting port should be ground.

3) The boom should be straight and the thread should be complete and clean. The boom extension can be spliced by the following methods:

① The lap joint is used for continuous welding on both sides, and the lap joint length is not less than 6 times the diameter of the boom.

② When using threaded connection, the length of the screw screwed into the connecting nut should be greater than the diameter of the boom and there should be measures to prevent loosening.

4) The rectangular air duct is installed horizontally at the maximum allowable installation distance, and its load-bearing crossarm, the diameter of the boom and the maximum spacing of the hanger must comply with the regulations.

5) When the air duct is vertically hoisted: the bracket spacing should be less than or equal to 2.4m, and each riser bracket should not be less than 2.

6) When the length of the air duct is more than 10m, a reinforced support to prevent the swing of the air duct should be provided. A single straight pipe should have at least 2 fixed points, and each system should not be less than 1. After the air duct is installed, the support and hanger should be evenly stressed without obvious deformation.

7) The position of the boom should be accurate, the shaft should be vertical, the cross arm should be flat, and the various booms, hangers and accessories used to support the hanger should be rust-proofed before installation.

8) 3~5mm wear-resistant rubber plate (shock pad) should be added to the contact surface of the cross arm and the air duct.

9) When the air duct passes through the fireproof and explosion-proof floor or ground that needs to be closed, a pre-embedded pipe or protective pipe with a wall thickness of not less than 1.6mm should be installed. Flexible material plugged.

10) There should be protection measures such as anti-leakage when the air duct goes out of the roof.

11) The air duct interface shall not be installed in the wall or floor. When the air duct is installed according to the wall or floor, the distance from the wall or floor should be greater than 150mm.

12) When installing the air duct, the supports, hangers and brackets should be arranged at equal distances, but they cannot be placed at the air vents, air valves, inspection doors and measuring holes. The distance between the hanger at the end of the air duct and the end of the air duct shall not be greater than 400mm.

13) The air outlet section with high pressure should be provided with more than 2 reinforcement supports.

14) The combustion performance of PVC connectors should reach the flame-retardant B1 level.

Phenolic air duct hoisting

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