VentilFlex® and VentilFlex® RKV

In its still soft state, the VentilFlex tube is pulled in the ventilation duct to be lined, where being inflated with steam, it takes up the shape of the duct and gets irreversibly hardened thus forming a heat and corrosion resistant, air-tight composite liner tube with the hardness of steel.

Thanks to the following features, VentilFlex® is suitable for lining and construction of air engineering ducts:

  • does not burn, does not conduct fire
  • does not corrode
  • perfectly air-tight
  • is of high hardness and lightweight
  • can vary in diameter
  • its boundary can be circle, square or other shapes
  • can line ventilation ducts up to 80 m without joints
  • can be painted without primer
  • does not emit any material hazardous to health

The connection pieces, curves are made of metal.

At ventilation equipment, distinction is made between systems of extraction and aspiration.
At the aspiration systems, stricter health protection and air tightness requirements apply.

The results of air engineering qualification procedure carried out in the VTT Technical Research Centre of Finland are the following:


From the air tightness aspect, VentilFlex® is of class D, which (apart from the special class E) is considered to be the highest class.