Abstract: The invention relates to a method and a coating device for applying a cladding layer onto the inner side of a carrier layer during the production of a multilayer heavy-duty pipe, with a pressure-exerting unit having a force application unit. A stable application of the cladding layer is achieved by having the coating device comprise a rolling tool with the pressure-exerting unit and the force application unit, and by providing the pressure-exerting unit with at least one pressure roller having a diameter that is smaller than the inside diameter of the heavy-duty pipe to be produced, and with at least one support element acting diametrically counter thereto with a supporting force in the operating state.

Abstract: A method for producing a multilayer large pipe having an outer support layer and at least one inner liner layer.

Abstract: The invention relates to a method and a coating device for applying a cladding layer onto the inner side of a carrier layer during the production of a multilayer heavy-duty pipe, with a pressure-exerting unit having a force application unit. A stable application of the cladding layer is achieved by having the coating device comprise a rolling tool with the pressure-exerting unit and the force application unit, and by providing the pressure-exerting unit with at least one pressure roller having a diameter that is smaller than the inside diameter of the heavy-duty pipe to be produced, and with at least one support element acting diametrically counter thereto with a supporting force in the operating state.

Abstract: A method for producing a steel tube, wherein a steel sheet is formed into tubular body having a round cross section in a bending process, welded in a subsequent welding process along longitudinal edges facing each other for producing a continuous longitudinal seam, and then subjected to a stress-relieving treatment. The production quality is improved, with reduced production time, because the stress-relieving treatment is performed in a process for concentrically truing along the circumference in at least one segment relative to the longitudinal axis thereof, while cold forming by compression (FIG. 1). The mechanical technological properties of the material are also thereby improved.