Abstract: A method is provided for joining the ends of steel pipes having male and female ends. The pipe is inserted with the male end into the pipe with the female end and a circular seam is welded, which is disposed at the inside of the female pipe for solidly connecting the pipe with the male end to the pipe with the female end. The male end is preferably provided with a ball section and the female end correspondingly with a ball shaped socket for allowing the pipe to be angled at the connection points. The invention provides the advantage that in automatic welding no large head holes have to be dug out.

Abstract: A method of and device for producing multi-layer pipes by helically winding a plurality of bands loosely arranged one above the other, which are individually withdrawn from a supply, straightened out, trimmed, and in the form of a band loop are conveyed to the forming station at the respective angle of lead-in corresponding to the respective pipe diameter, whereupon the layers are together welded to form a pipe strand which is subsequently cut into individual pipes. All bands are supplied and advanced independently of the irregularities of the respective longitudinal band edge shape in steadily straight lead-in directions, and all band edges are machined together to a possible maximum width in coordination with each other whereupon the bands are driven together while the welding gap is controlled in conformity with their band edge shape merely by pivoting the pipe.