Abstract: A welded joint between pipes and pressure bearing elements, such as tube plates, pressure tanks, accumulators, or the like. The pipes and elements have a lip-shaped extension in the joint region. The joint connection is effected in this joint region by a full through-weld which is substantially free of crevices. The joint connection of pipe-to-element lies within the region where the pipe penetrates the element. A free space remains below the element lip between the pipe and the element. The space which is located above the element lip, and which is defined or bordered by the element lip, the pipe, and a centering bushing or sleeve known per se, is filled up with welding material. The centering bushing serves only as a temporary aid during the welding operation and is removed, e.g. is bored out, after the welding operation has been completed.

Abstract: A method of connecting a pipe to a pressure conveying element, especially a pipe plate, a pressure container, and a collector, according to which the pressure conveying element is within the region of its intended connection with the pipe provided with lips. After the pipe provided on its inside and outside with a lip has been introduced into the pressure conveying element, the pipe is at its outer lip connected to the lip of the element by a complete through weld. Subsequently a centering bushing is introduced into the pipe and is clamped therein so that the outer surface of the centering bushing together with the inner surface of a bore in the conveying element--which bore is substantially coaxially arranged with regard to the pipe--forms a flat annular trough, whereupon the space between the outside surface of the centering bushing and the inner surface of the trough is filled with welding material.

Abstract: Method and apparatus for differentially rolling-in tubes into plates and walls, especially of heat exchangers, according to which the magnitude of the expansion of the tube section to be rolled-in into the respective wall or plate is predetermined, is ascertained and maintained during the rolling-in action. The magnitude of the tube expansion for connection of the tube to the respective plate or wall is adjustable in conformity with a program and has different values over the rolling-in length of the tube.