Abstract: A connecting element including an annular sleeve that has a self-supporting inner wall and a flexible outer wall, and a space between the inner and outer walls for introducing a preferably hardenable free-flowing filling medium into the connecting element to expand the connecting element radially outwardly to contact surfaces of adjacent pipe structures. A feed opening is provided in one of the inner wall and the outer wall to provide access to the space between the walls to permit introduction of the filler material. The connecting element is particularly suitable for sealing the joint between a multi-walled main pipe and a branch pipe extending from the main pipe.

Abstract: A tube winding apparatus includes a drum having a jacket formed by elongated cylindric members. A number of these members, namely the circumferential rollers, is motor driven basically by the normal drive of the winding apparatus. Such supports the tube and web drive and the feeding or advancing of the tube.

Abstract: In the method for placing a plastic tube having a predetermined inherent stiffness into existing openings or through-passages a hardenable material, usually a hardenable synthetic resin, is applied onto the wall of the tube before placing the latter into the opening or through-passage. This hardenable material hardens completely only after a certain time period, i.e. after the tube has been brought into its desired position, to thereby increase the original inherent stiffness of the plastic tube. The device for carrying out the method includes apparatus for applying the stiffening material onto the wall surface of the tube.

Abstract: A profiled band that includes two longitudinal edges of which one is provided with a groove and a parallel extending rib is allocated to the other one, which mentioned parts form a locked seam when the band is wound to a pipe, which seam is mechanically held in its operational position. The band is specifically suitable for an in situ production of wound pipes having a helically extending seam.