The method involves using an outer force-absorbing pipe (1) made of carbon steel with standard length, 6-12 m, and a material thickness of approximately 15-40 mm, dependent upon the work pressure in the conduit. The pipe lengths are welded together to form a suitable length of up to approximately 1000 m. Welding takes place on both the outside and the inside. The inside of the pipes is then coated with a corrosion-inhibiting and friction-reducing composition (5), preferably wax, and a suitable distance material (4). An inner pipe (2) is made of stainless steel of the type 654 SMO (RTM) produced by Avesta Sheffield AB which is very corrosion and wear-resistant. It is produced from a strip-form body wound to pipe shape and along its length is formed a ridge (3) or ridges. Tractive and pressure forces are used for placing the inner pipe in the outer. Radially outwardly directed pressure is then applied to the inner pipe inner surface, pressing the pipe exterior into the wax and distance material. At the same time, the ridges are pressed outwards.
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