Types of spiral duct:
Spiral air duct is generally divided into three categories according to material in the market: galvanized spiral air duct, stainless steel spiral air duct and composite spiral air duct. Among them, the stainless steel air duct has the best quality and strong applicability, but the price is high. At present, the most widely circulated spiral air duct in the market is galvanized sheet. Galvanized sheet spiral air duct is basically the characteristic of stainless steel spiral air duct, but the price is only two-thirds or even lower than that of stainless steel air duct. Composite spiral air duct is generally used in places with common external environment and low requirements for air duct. Features: because the iron sheet is prone to chemical reaction in various environments, resulting in corrosion and rust. Zinc hardly changes in dry air. In humid air, a dense basic zinc carbonate film will be formed on the zinc surface. The spiral air duct is mainly coated with a layer of zinc on the iron sheet of the air duct to protect the iron sheet. The protective and decorative properties of zinc coating can be significantly improved after passivation, dyeing or coating with light protective agent.