Specifications, Installation Specifications and Purchase Guide of Galvanized Air Ducts

 

As the core component of building ventilation systems, galvanized air ducts are widely used in commercial, industrial and public facility fields due to their excellent performance. This article will systematically analyze its technical parameters, installation standards and purchase key points, providing practical references for engineering design and construction.

 

I. Technical Parameters and Application Scope

Galvanized air ducts are cold-rolled from galvanized steel sheets. The pipe diameter ranges from Ø80 to Ø2000 mm, the steel sheet thickness is 0.5 - 2.0 mm, and the standard section length is 4 m. Customized production is supported. Its typical application scenarios include:

-Commercial Places: Fresh air systems and smoke exhaust pipes in hotels, shopping malls and office buildings.

-Industrial Facilities: Ventilation and dust removal systems in chemical fiber factories, electronic workshops and pharmaceutical clean rooms.

-Public Works: Air circulation systems in subway tunnels, civil air defense basements and medical institutions.

 

II. Core Performance Advantages

1.Structural Stability: High-strength galvanized steel sheets combined with the lock-seam forming process ensure the rigidity of the pipes, and the pressure-bearing capacity meets the requirements of medium and high-pressure systems.

2.Aerodynamic Optimization: The smooth inner wall reduces the wind resistance coefficient by 15% - 20%, reducing the energy consumption of the fan and suppressing secondary noise.

3.Construction Convenience: On-site cutting, hole-making and assembly are supported. The flange connection adopts a snap-spring structure, increasing the installation efficiency by more than 40%.

4.Long-term Anti-corrosion: The double protective layer (zinc layer + zinc-rich epoxy paint) passes the 240-hour neutral salt spray test, and the service life exceeds 20 years.

 

III. Key Installation Technical Specifications

1.Support Spacing Requirements

   - Horizontal Installation: When the diameter ≤ 400 mm, the bracket spacing ≤ 4 m; when > 400 mm, the spacing ≤ 3 m.

   - Vertical Installation: The spacing between fixed points ≤ 4 m, and at least 2 load-bearing brackets should be set for a single pipe.

   - For special systems (such as clean air-conditioning), all-thread suspension rods with shock-absorbing gaskets should be used.

2.Flange Assembly Standards

   - The four corners of the angle steel flanges are welded with a 45° chamfer, and the inner diameter is 2 - 3 mm larger than the outer diameter of the air duct.

   - The bolt hole spacing ≤ 120 mm, and the distance from the corner ≤ 30 mm to ensure the interchangeability of the flanges.

   - After the flanges are riveted with the air duct, the flanging width is 6 - 7 mm, and the flatness deviation ≤ 1 mm.

3.Avoidance Principle

   The brackets should be more than 200 mm away from air outlets, valves and other regulating devices to avoid airflow disturbance. Flexible connection nodes should be added in seismic fortification areas.

 

IV. Key Points for Purchase Decision

1.Parameter Matching: Calculate the pipe diameter according to the air volume, and select the steel sheet thickness according to the system pressure (≥ 0.5 mm for low-pressure systems, ≥ 1.0 mm for high-pressure systems).

2.Process Inspection: Focus on checking the tightness of the lock-seam, the flatness of the flanges (the gap detected by a feeler gauge ≤ 0.5 mm) and the integrity of the coating.

3.Cost Control: The quotation for regular specifications on e-commerce platforms is about 5 - 50 yuan per meter. For project procurement, it is recommended to have the samples reviewed by a third-party testing institution.

 

V. Maintenance and Upgrade Suggestions

During daily use, the airtightness of the joints should be checked regularly, and it is recommended to clean the internal dust every 3 years. For renovation projects, BIM technology can be used to preview the pipe layout scheme to avoid conflicts with mechanical and electrical pipelines.

 

Through scientific selection and standardized construction, galvanized air ducts can significantly improve the energy efficiency ratio of the ventilation system and reduce the full-life cycle maintenance cost. It is recommended to give priority to manufacturers with ISO 9001 certification during project implementation, and keep the material inspection reports as the acceptance basis.