Flexible pipe e.g. for undersea oil flow line has two corrugated metal layers made from spiral-wound strip with crests and troughs

摘要

The flexible pipe has an inner impermeable metal tube (1), a shield (2), an optional polymer sealing sleeve (3), reinforcing layers (4, 5) and an outer protective sleeve (6). The metal tube is in two coaxial layers made from spiral-wound corrugated metal strip with three crests and two troughs, wound so that the crests of one winding fit into the troughs of another and welded together. The strip is wound so that its corrugations lie at an angle of over 80 degrees to the axis of the pipe.