Patent ID: 8366351
Filing Date: 2013-02-05
Classification: F16L,Y10T

Abstract:
1. A method of making steel undersea pipes designed to convey corrosive fluids including water, the method comprising: 1) acting in a workshop on land to assemble together respective ends of at least two unitary pipe elements by means of first welds so as to form pipe strings; and 2) acting at sea from a laying ship to assemble together respective ends of said strings by means of second welds so as to form a pipe; wherein: in step 1), said strings are made from at least two end unitary pipe elements, each of which has a first end designed to constitute one of the two ends of a said string, an anti-corrosion cladding made of stainless steel or of a corrosion-resistant alloy extending over the inside surface made of carbon steel of each said end unitary pipe element over a first length (l prior to step 2), at least one first partial lining of the inside surface of said string is implemented by means of a tubular liner made of a flexible plastics material that is applied against said inside surface of the string, each said first lining covering each said carbon-steel first weld between the respective ends of the unitary pipe elements of the same string whose inside surface is made of the same carbon steel not clad with said stainless steel or with said corrosion-resistant alloy; and in step 2), said first ends are assembled together by second welds consisting of anti-corrosion welds performed with the same said stainless steel or with the same said corrosion-resistant alloy.