High pressure tube and method of manufacturing the same

Abstract

Tube having a length of more than 10 m suitable for high-pressure applications with internal pressure of 2 bar or more, and which is not afflicted with disadvantages exhibited by tubes produced by conventional drawing or cold pilger milling methods. The tube has a wall thickness equal to or larger than the internal diameter, an axial length of 12 m or more, a tensile strength Rm of 850 N/mm2 or more, and a mean roughness index Ra of the inner wall surface of 0.8 μm or less. Furthermore, a method of manufacturing such a tube forms a hollow into a tubular intermediate in a first forming step according to the cold forming method, the tubular intermediate thus obtained is annealed, and the annealed tubular intermediate is formed into a tube in a second forming step according to the cold forming method.

Dependencies are inferred from the claim text.