Angle iron flange air duct

Overview of angle iron flange air duct

Angle iron flange air duct is a type of air duct connection made of angle iron for the flange of galvanized steel sheet air duct. Generally, large air ducts have flanges, while small air ducts do not have flanges. Its advantage is to save materials and reduce engineering investment; Low air leakage, reduced energy consumption, and saved operating costs. Ordinary ones can use A3 angle iron (the size depends on the air duct and there are national standards), while stainless steel angle iron can be used for stainless steel air ducts. The production process adopts welding and requires the angle iron to be straight. A3 requires anti-corrosion treatment and precise size requirements. It can be 3-5mm larger than the air duct, which is conducive to connecting with the air duct. The most important thing is that the screw holes must be made accurately, which is conducive to the installation and connection of the air duct.

The finished product of angle steel flange galvanized air duct has a straight surface and a standard and beautiful appearance, laying a good foundation for convenient and fast installation on the construction site. The common plate flange air duct, also known as the non flange air duct, is made in a faster, more convenient, and smaller air leakage rate than traditional rectangular air ducts.

Application

The product is widely used in large shopping malls, office buildings, subway stations, large supermarkets, modern factories for fire smoke exhaust and ventilation, air conditioning and ventilation, dust exhaust and ventilation, etc.

Performance characteristics

Its advantage is to save materials and reduce engineering investment; Small air leakage, reduced energy consumption, and saved operating costs, which is highly welcomed by construction companies. Developed countries such as the United States and Europe have been using flange free connections for air ducts since the 1990s, and this process has been widely applied in various engineering projects.

Installation of air ducts

When installing angle steel flange air ducts, the following points should be noted:

1. When the size of the large side of the air duct is above 1000mm, angle steel, flat steel, steel pipe, Z-groove, reinforcement bars, threaded screws, etc. can be used for internal and external reinforcement of the duct.

2. When the size of the large edge of the angle steel flange air duct is between 630-1000mm, it should be directly reinforced by pressing steel bars on the production line. The arrangement should be regular, the spacing should be uniform, and there should be no obvious deformation on the plate surface.

3. The reinforcement of angle steel or reinforcing bars should have a height less than or equal to the height of the air duct flange, arranged neatly, and evenly spaced.

4. The pipe is supported and reinforced with threaded screws, and its special gasket is placed on the inner wall of the external insulation air duct.

5. When the cross-sectional area of the air duct is greater than 1250 * 630, in order to maintain the perpendicularity of adjacent walls, it is advisable to use 90 ° C diagonal supports to reinforce the four corners inside the air duct.

6. When the length of medium and high pressure system ducts is greater than 1250mm, reinforced frames should be used for reinforcement.

Galvanized angle iron flange air duct

3.2.1 The production of galvanized air ducts with angle iron flanges shall meet the following requirements:

The thickness of the sheet metal for rectangular ducts and their accessories should not be less than the specifications in Table 3.2.1-1.

Table 3.2.1-1 Thickness of Ordinary Steel Plate or Galvanized Steel Plate Duct Sheet (mm)

2. The splicing of galvanized steel plates or color coated steel plates should be done by biting or riveting, and there should be no cross shaped splicing joints. The coated surface of the color coated steel plate should be located on the inside of the air duct, and damage to the coated layer should be avoided during processing. Damaged parts should be repaired.

3. Welding air ducts can be done in three forms: lap joint, corner joint, and butt joint. The position of the weld seam is shown in Figure 3.2.1. Before welding the air duct, rust and oil should be removed. The weld seam should be well fused and flat, with no defects such as cracks, weld beads, penetrating slag inclusions, or pores on the surface. The deformation of the welded plate should be corrected, and welding slag and spatter should be removed completely. Ducts with a wall thickness greater than 1.2mm can be connected to flanges using continuous welding or flanged intermittent welding. The pipe wall and flange inner port should be tightly attached, and the weld seam should not protrude from the flange end face. The length of the intermittent weld seam should be between 30-50mm, and the spacing should not exceed 50mm. Figure 3.2.1 Welding position of the air duct weld seam

The connection between the dust removal system duct and the flange should use full welding on the inside and intermittent welding on the outside, and the end face of the duct should be no less than 5mm from the flange interface plane.

5. The reinforcement of air ducts shall comply with the following regulations:

1) Thin steel plate flange air ducts should be rolled with reinforcing ribs, and the protruding part of the reinforcing ribs should be located on the outer surface of the air duct, with uniform spacing and no obvious deformation on the plate surface.

2) When the flange strength of the air duct is lower than the specified strength, external fixing frames and internal supports can be used for reinforcement. The distance between the reinforcement piece and one end of the air duct connecting flange should not exceed 250mm

3) The height of the externally fixed profile should be equal to or less than the height of the air duct flange, and the spacing should be uniform and symmetrical. The connection with the air duct should be firm, and the spacing between bolts or rivet points should not exceed 220mm. The four corners of the externally fixed frame should be connected as a whole.

4) The arrangement of support reinforcement inside the air duct should be neat, with even and symmetrical spacing. Special gaskets should be installed at the stress (pressure) surfaces of the air duct at both ends of the support. When using pipe sleeve internal support, the length should be equal to the length of the air duct connection.

5) The stiffness level and reinforcement spacing of rectangular ducts should be selected and determined according to Tables 3.2.1-2, 3.2.1-3, 3.2.1-4, 3.2.1-5, and 3.2.1-6.