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

Abstract: A method for producing a multilayered large pipe out of an outer pipe which forms a supporting layer, and at least one inner pipe, which forms a lining layer and is bent from a lining sheet and welded along a longitudinal seam or is seamless, including the following sequence of method steps: preparing a wavy inner pipe which is bent from the lining sheet with a continuously rounded wavy contour extending transverse to a longitudinal axis of the large pipe and with wave troughs and wave crests extending continuously over a length of the wavy inner pipe where the maximum outer diameter of the wavy inner pipe is smaller than the inner diameter of the outer pipe; inserting the wavy inner pipe into the outer pipe; and expanding the wavy inner pipe by an expansion force acting in a radially outward direction until it assumes an almost round form and, after removal of the expansion force, is clamped in a nonpositive way in the outer pipe, and subsequent relaxation.

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

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.

Abstract: The invention relates to a method for producing a steel tube, wherein a steel sheet (4) is formed into tubular body (1.2) having a round cross section in a bending process (a), welded in a subsequent welding process (b) along the 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, in that the stress-relieving treatment is performed in a process (c) 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.

Abstract: The present invention provides a method for performing a diagnostic operation in motor vehicles, a method for operating a motor vehicle, a electronic control unit, and an electronic testing device, that differs from conventional methods and/or control units and/or testing devices by at least one characterizing feature and that it is novel relative to the known methods and/or devices.

Abstract: A vehicle including a device for determining vehicle operational data and for determining distance traveled by the vehicle. A memory is provided for storing the operational data together with the distance traveled as paired values for subsequent diagnostic and maintenance purposes. Signals representative of engine rotational speed, transmission input rotational speed, and torque transmitted by the clutch are sensed for determining clutch performance loss values, and the performance loss values are stored in the memory as paired values along with the vehicle distance traveled.