The spiral air duct is manufactured by using the steel strip coil, using the air duct molding machine to bite the bone shape at one time, rolling it into a circular tube along the spiral involute track, pressing the seam together, and finally cutting it according to the required length. Since it was put on the market, because of its excellent performance and low operating cost, it has been widely used in shipbuilding, ventilation, air conditioning, purification, bridge dust removal, airport, tunnel and other construction industries.

送冷風和送熱風更常見的方式是空調的管道，需要保溫。還可在內部粘貼保溫材料，使風管具有美觀的螺旋狀外觀，并可避免吊頂，降低工程造價。螺旋風管的制造自動化程度高，生產速度非常快。一般風管每分鐘可產生20～40米，是由于其原材料鍍鋅帶鋼低于整體鍍鋅鋼板，其工廠化生產和標準標準化使成本低于矩形風管。

The most common way to supply cold air and hot air is the pipe of central air conditioning, which needs thermal insulation. It can also paste thermal insulation materials inside to make the air duct have a beautiful spiral appearance, avoid ceiling and reduce the project cost. The manufacturing of spiral air duct is highly automated and the production speed is very fast. Generally, the air duct can produce 20-40 meters per minute, because the price of its raw material galvanized strip steel is lower than that of the overall galvanized steel plate, and its factory production and standardization make the cost lower than that of rectangular air duct.

螺旋風管選用技術設備后，如果配備與其他工序相對應的加工設備，各工序空調風管的加工進度和質量都會有較大提升，但加工工藝仍為多工序分離加工，仍需大量人力在多臺設備上旋轉，空調風管的加工規劃、加工力和質量仍停留在較低階段。可喜的是，選用普通板式法蘭連接技術后，空調風管的加工工序不僅少了，還省去了許多人工操作工序，仍需下料、切角、壓筋、普通板式法蘭成型、咬角縫、組裝等工序。

After selecting advanced technical equipment for spiral air duct, if equipped with processing equipment corresponding to other processes, the processing progress and quality of air duct in each process will be greatly improved, but the processing process is still multi-process separation processing, and a lot of manpower is still needed to rotate on multiple equipment, and the processing planning, processing power and quality of air duct in air conditioning still remain at a low stage. Fortunately, after selecting the common plate flange connection technology, the processing procedures of the air conditioning duct are not only less, but also many manual operation procedures are saved. There are still processes such as blanking, corner cutting, rib pressing, common plate flange forming, undercut joint, assembly, etc.

接頭為周向，接頭強度遠高于徑向直接頭，所以在1.5倍工作壓力下能保證接頭處無裂紋，因為其原材料鍍鋅帶鋼低于整片鍍鋅鋼板，其工廠化生產和標準標準化使成本低于矩形風管;另外，由于其支吊架需求量小，安裝工作量小，所以總成本低。由于矩形風管四角易發生湍流，有用流動面積減小，空氣流動性好，有用流動面積大，產品的二次噪聲因強度大而小。因此，風管振動引起的低頻噪聲更小，空氣流動性能好，系統壓降小，日常運行系統耗電少。

The joint is circumferential, and its strength is much higher than that of the radial straight head, so there is no crack at the joint under 1.5 times of working pressure, because its raw material galvanized strip steel is lower than the whole galvanized steel plate, and its factory production and standardization make its cost lower than the rectangular air duct; In addition, the total cost is low due to the small demand for its supports and hangers and the small installation workload. Because the four corners of the rectangular air duct are prone to turbulence, the useful flow area is reduced, the air flow is good, the useful flow area is large, and the secondary noise of the product is small due to the high intensity. Therefore, the low-frequency noise caused by air duct vibration is smaller, the air flow performance is good, the system pressure drop is small, and the daily operation system consumes less power.