Fire resistant ventilation duct - has inner and outer tubes formed from layers of aluminium and plastic foam

摘要

Ventilation duc comprising two tubes (1, 2) sliding one inside the other, each tube consisting of layers of aluminium alternating with layers of cellulose material and cellular thermoplastic material, the layers of aluminium being on the outside of the outer tube and the inside of the inner tube. Straight sections are easily joined together and the joint is sealed with adhesive tape preferably made of aluminium covered with heat resistant adhesive. Bends (20) have the same external diameter as the outer tube (2) and the same internal diameter as the inner tube (1) and have several outer layers of aluminium. The duct has high fire resistant properties.