Spiral ducts in the market are generally divided into three categories based on material: galvanized spiral ducts, stainless steel spiral ducts, and composite spiral ducts. Among them, stainless steel air ducts have the best quality and strong applicability, but they are expensive. The most widely circulated spiral duct on the market currently is galvanized sheet. Galvanized sheet spiral air duct is basically the characteristic of stainless steel spiral air duct, but its price is relatively only two-thirds or even lower than that of stainless steel air duct. Composite spiral ducts are generally used in places where the external environment is relatively ordinary and the requirements for ducts are not too high. Due to the easy chemical reactions of iron sheets in various environments, corrosion and rusting can occur. Zinc hardly changes in dry air. In humid air, a dense alkaline zinc carbonate film forms on the surface of zinc. Spiral ducts are mainly coated with a layer of zinc on the iron sheet of the duct to provide protection for the iron sheet. After passivation treatment, dyeing or coating with light protectants, the protective and decorative properties of zinc coatings can be significantly improved.

Spiral ducts have the following characteristics:

1. Galvanized threaded air ducts have a smooth appearance, without zinc nodules or burrs, and are silver white in color;

2. Galvanized threaded air ducts are easy to install and have fewer connection points;

3. Galvanized threaded ducts have low ventilation resistance and low ventilation noise;

4. Galvanized threaded air ducts have good strength and rigidity;

5. The thickness is controllable and can be freely selected within 5-107 μ m;

6. No hydrogen embrittlement, no temperature hazards, and can ensure that the mechanical properties of the material remain unchanged;

7. Can replace some processes that require hot-dip galvanizing;

8. Good corrosion resistance, with a neutral salt spray test lasting up to 240 hours;

9. Completed by hot-dip galvanizing method, suitable for various strong corrosive environments such as strong acid, alkali mist, etc;

10. We can design and customize various specifications of air ducts according to customer requirements.

Compared with traditional handmade white iron pipes, the mechanism of spiral air ducts has the following advantages:

(1) Good sealing performance.

(2) Both strength and rigidity are good.

(3) Low ventilation resistance, low ventilation noise, and round pipes are superior to square pipes.

(4) Easy installation with few connection points.

(5) High grade, beautiful appearance.