METHOD FOR PRODUCING A LARGE MULTILAYER PIPE

摘要

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.

主权项

1. A method for producing a multilayered large pipe out of an outer pipe (1), which forms a supporting layer and is welded or seamless and thus closed on a casing side, and at least one inner pipe (2) 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 the wavy inner pipe (20) which is bent from the lining sheet or is seamless and is closed on the casing side, with a continuously rounded, wavy contour (22) extending transverse to a longitudinal axis of the large pipe and with wave troughs (21) and wave crests (23) extending continuously over a length of the wavy inner pipe (20), where a maximum outer diameter (ODL) of the wavy inner pipe (20) is smaller than an inner diameter (IDT) of the outer pipe (1); inserting the wavy inner pipe (20) into the outer pipe (1); and expanding the wavy inner pipe (20) 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 (1), and subsequent relaxation.