A METHOD FOR FORMING A CLOSED CANAL IN A PIPE WALL, AND SUCH A PIPE

摘要

A method for the manufacture of a pipe (1) for use in petroleum exploitation, the manufacturing process comprising roll-forming of a steel plate (11) to form a hollow (0') with a longitudinal gap for being welded to form said pipe (1), the method characterized by the following steps: * said steel plate (11) having lateral edge surfaces (221, 222), in which along on or more of said lateral edge surfaces (221, 222) are formed longitudinal grooves (22, 22') thus forming first bridge parts (23, 23') comprising a first lateral edge surface (221i, 222i) along a first side of said groove (22, 22'), and thus forming a second lateral edge surface (221y, 222y) on a second side of said groove (22, 22'); welding of said first bridge parts' (23, 23') first lateral edge surfaces (221i, 222i), thereby joining said grooves (22, 22'), joining said second lateral edge surfaces (221y, 222y) to form a lid (3) to cover said grooves (22, 22') to form a canal (2) in the wall of said pipe (1).