Industrial manufacture is achieved through continuous rolling of a sheet metal strip (137mm), the spiral seam is a mechanical 4-ply lock (RL-1 SMACNA), with no welded, soldered or riveted seams to distort material or mar coated surfaces.

The fittings are fabricated with transversal, hermetic standing seam (like L-4 SMACNA) and the longitudinal are overlapped (RL-3 SMACNA) and fastened with spot welding and sealed with silicone amongst others. The standard coupling between the fittings and round ducts are beaded sleeve joint (RT-1 SMACNA fitting male – duct female), existing van stone flange joint bolted (RT-2 SMACNA) or fast fit clamp amongst others.

It has an ideal shape thanks to its circular section that obtains the maximum area with the minimum perimeter possible, allowing important economies in the installation. Its fabrication complies with the international technical standards of SMACNA.


  • All the production process is done in the factory and it arrives ready to install.
  • Smaller and more precise delivery times (according to available stock)
  • Lower installation costs as its easier and quicker. No specialized labor or tools are required.
  • Lower weight, thanks to its greater structural resistance making installation easier.
  • Reduces high frequency noise problems originated in the ducts walls.
  • Excellent presentation, avoiding the extra costs of a ceiling.
  • Re-usable in case of moving or system expansion.
  • Waste disappears through ordering exact amounts.
  • Less amounts of joints and supports.
  • Measurements to control air flows are easier to do.
  • Interior cleaning is more effective and economical when required.
  • Lower operation costs, thanks to lower friction losses, heat gains and leaks.
  • Important savings (21% average) in thermal insulation when required.
  • Lower transport costs allowing nesting of some diameters in others.
  • Better performance per kilo or m2 installed, thanks to its efficient circular section ( average savings 35%)
  • Easy and total control of inventories.
  • Simple method of quantifying the cost of the required amounts.
  • Factory guarantee