Abstract: A process for the producing of pipes, in particular large pipes, by the UOE process, in which the pipes are sized by cold expansion after internal and external seam welding. In order to render the strength characteristics and deformation characteristics substantially homogeneous in the circumferential direction of the pipe and in order to adjust determined characteristics in a directed manner, the pipes are conditioned by a combined application of cold expansion and cold reduction. The sequence and degree of expansion and reduction, respectively, are established depending on the required profile.

Abstract: A double-wall hollow body comprises an inner hollow body and a cooperating outer hollow body. The outer hollow body is frictionally attached to the inner hollow body, and is radially spaced from the inner body so that an annular space is formed between the two bodies. Acoustic-damping insulating material is contained within the annular space, and forms an interlayer between the inner and outer bodies. An end of the double-wall hollow body is formed by respective ends of the inner and outer hollow bodies that rest directly against each other without insulating material. The inner hollow body is separated over an entire circumference from the outer hollow body by the insulating interlayer. Various methods of manufacturing the foregoing double-wall hollow body are also described. For instance, to apply the insulating material to the inner hollow body, such body may be heated and then rolled into the insulating material.

Abstract: Hollows are hydraulically widened as their ends are closed by sealing heads which include inflatable sealing rings bearing against the hollow at a pressure that is always in excess of the widening pressure applied to the hollow.

Abstract: A mold for continuous casting of slab ingots is constructed to have wide sides which extend lower than the narrow sides leaving gaps below the bottom edges of the narrow mold sides in which rolls are placed for engaging the emerging narrow side of the ingot held in the same level still by the wide sides of the mold. The force exerted by these rolls upon the ingot is related to the thickness thereof.