Cable passage sheath in fire deflecting partition wall - has foam material inflating at high temp. in areas not stiffened by ring

摘要

A tubular sheath passing through a hole in the wall, with end faces sealed with insulating materials, is used in the fire-deflecting cable passage through partition walls, or similar. The insulation can comprise fireproof substances which foam up with gastight effect in high temperatures. There are spaced stiffening zones on the sheath, at an interval from its end faces, in closed peripheral ring form, with higher bend and tension-resistant rigidity than the other parts. In the non-stiffened zones only, the sheath is inflatable under the influence of the foaming insulating material. The stiffened zones may be in seam form, at partition wall thickness distances apart.