Stainless steel spiral air ducts are circular ventilation ducts made from high-quality stainless steel sheets using advanced spiral lock-forming technology. Due to their excellent corrosion resistance, high strength, and superior airtight performance, they are widely used in ventilation, smoke exhaust, and process piping systems with high requirements for cleanliness, corrosion resistance, or high temperature resistance.

 

In terms of sheet thickness and strength, the thickness of the air duct must be comprehensively determined based on the system's working pressure and pipe diameter. High-pressure or negative-pressure systems have stricter requirements for sheet thickness. When the diameter or long-side dimension of the air duct is large, to meet the strength requirements for resisting high negative pressure, the length of a single section is usually required not to exceed 1 meter, the reinforcement spacing should be no more than 1 meter, and flange connections should be adopted to ensure the overall structure is stable and reliable.

 

The choice of connection technology depends on the sheet thickness. For sheets with a thickness of 1 mm or less, lock-seam or riveting is applicable; when exceeding 1 mm, argon arc welding must be used, and gas welding is strictly prohibited. The welding material must match the stainless steel base metal, and after welding, welding slag and spatter must be thoroughly cleaned to ensure a smooth inner wall. Especially in oil fume exhaust systems, the flange and the duct body must use full welding technology to achieve complete sealing.

 

If carbon steel flanges or fasteners are used, their surfaces must undergo anti-corrosion treatments such as chrome plating or galvanizing to prevent electrochemical corrosion and ensure the long-term operational stability and service life of the system.

 

Quality acceptance shall implement corresponding standards according to the system category. The allowable air leakage rate of metal circular air ducts is generally 50% of that of rectangular air ducts. During acceptance, product qualification certificates should be verified, and on-site re-inspection should be conducted if necessary to ensure that their strength and tightness meet the design requirements.

 

Stainless steel spiral air ducts have several significant advantages: excellent corrosion resistance, suitable for humid, corrosive gas, or high-cleanliness environments; high strength and long service life; smooth inner walls, low wind resistance, low operating energy consumption, and low noise; neat and beautiful appearance, easy to clean and maintain. They are an efficient and reliable ventilation duct solution.

 

Their design, production, and installation must strictly comply with relevant technical specifications to ensure safe, efficient, and long-term operation of the system, meeting various ventilation and exhaust needs.