Method for producing a steel underwater pipe that is able to carry a corrosive fluid

Patent metadata

Field	Value
Publication number	US-2024255076-A1
Application number	US-202418602757-A
Country	US
Kind code	A1
Filing date	Mar 12, 2024
Priority date	Sep 10, 2018
Publication date	Aug 1, 2024
Grant date	—

Abstract

A method for producing a steel underwater pipe for carrying a corrosive fluid, includes the successive steps: applying a layer of corrosion-resistant steel alloy on a terminal part of the internal wall of each pipe element from its end to be welded; the application of a plastic coating, on the internal wall of each pipe element; covering only a first part of the layer of metal alloy, a terminal part of the layer of metal ally on the side of the end to be welded of each pipe element not being covered by the plastic coating; the coaxial insertion and the crimping of a compression ring against the terminal part of the plastic coating; and the assembly by welding directly together the ends of two pipe elements by a corrosion-resistant steel alloy weld.

First claim

1 . A pipe element comprising:
a layer of corrosion-resistant steel alloy on a terminal part of length L 1 of an internal wall of said pipe element from a first to be welded; a protective coating of plastic material applied directly on the internal wall of said pipe element; and covering a first part of length L 2 of said layer of corrosion-resistant steel alloy, a second part of length L 3 of said layer of corrosion-resistant steel alloy on a side of said first end to be welded of said pipe element not being covered by said protective coating of plastic material, a compression ring of corrosion-resistant steel alloy inserted inside the pipe element comprising:
(a) a first annular part of length L 4 comprising an outer side face which is corrugated, over a part at least of its length L 4 , said first annular part being crimped against a pressure side face of at least one terminal part of said protective coating of plastic material covering said first part of said layer of corrosion-resistant steel alloy, and
(b) a second annular part of length L 5 less than L 3 , continuing said first annular part, applied against a part of said second part of the layer of corrosion-resistant steel alloy not covered by said coating of plastic material, said second annular part of said compression ring extending from and against an end of said coating of plastic material until a free end of said compression ring closest to the first end to be welded of the pipe element, welded against said second part of said layer of corrosion-resistant steel alloy not covered by said protective coating of plastic material.

2 . The pipe element according to claim 1 , wherein,
a first part of the pressure side face of the layer of corrosion-resistant steel alloy intended to be covered by a terminal part of said protective coating of plastic material is machined for corrugation, in part at least, and said compression ring comprises at least:
(a) one first annular part, the outer side face of which is corrugated in part at least, able to cover said terminal part of said protective coating of plastic material, in line with at least the corrugated part of the first part of the layer of corrosion-resistant steel alloy of which the pressure side face is covered by the terminal part of said protective coating of plastic material, said first annular part extending in line with the second part of the layer of corrosion-resistant steel alloy not covered by said coating of plastic material, and
(b) one said second annular part the pressure side surface of which is of conical shape connecting the pressure side surface of the first annular part and the surface of the second part of the layer of corrosion-resistant steel alloy not covered by said coating of plastic material, at the end of said second annular part of the compression ring welded against said second part of said layer of corrosion-resistant steel alloy not covered by said protective coating of plastic material.

3 . The pipe element according to claim 1 , wherein a second end of said pipe element is arranged not to be welded and is provided without said compression ring, the second end comprises a rigid tubular junction sleeve of thermoplastic material, a first longitudinal end of said sleeve being in sealed contact or being formed in a continuous piece with the other end of said coating of plastic material inside said pipe element, a second end of said sleeve protruding by a length L 0 outside the other end of said pipe element.

4 . The pipe element according to claim 3 , wherein said second end of said sleeve protruding outside the second end of said pipe element is inserted inside another pipe element in sealed contact, with the end of a coating of plastic material set back by a length L 0 inside said other pipe element relative to the end of said other pipe element assembled by steel alloy welding with said pipe element.

5 . A pipe element that is able to carry corrosive fluids, an internal wall of which is partially lined by a protective coating of plastic material of a liner type wherein an assembly by welding directly together ends of at least two pipe elements is provided for, wherein a method for making the pipe element comprises successive steps:
a) applying a layer of corrosion-resistant steel alloy on a terminal part of length L 1 of the internal wall of each pipe element from a first end to be welded; b) machining on the pressure side surface of the layer of corrosion-resistant steel alloy, c) applying a protective coating of plastic material directly on the internal wall of each pipe element; and covering a first part of length L 2 of said layer of corrosion-resistant steel alloy, a second, adjacent part of length L 3 of said layer of corrosion-resistant steel alloy on a side of the first end to be welded of each pipe element not being covered by said protective coating of plastic material, d) coaxially inserting of a compression ring of corrosion-resistant steel alloy inside said terminal part of each pipe element and the crimping of a first annular part of length L 4 of said compression ring against the pressure side face of the terminal part of said protective coating of plastic material covering a first part of said layer of corrosion-resistant steel alloy, and the welding of a free end of a second annular part of said compression ring against a second part of said layer of corrosion-resistant steel alloy not covered by said protective coating of plastic material, said first annular part of the compression ring comprising an outer side face which is corrugated, over a part at least of its length said second annular part of said compression ring continuing said first annular part, said second annular part being applied against a part of said second part of the layer of corrosion-resistant steel alloy not covered by said coating of plastic material and extending over a length L 5 less than L 3 , from and against the end of said coating of plastic material until said free end of said compression ring closest to the first end to be welded of the pipe element, and e) assembling by welding directly together the ends to be welded of two pipe elements by a corrosion-resistant steel alloy weld;
wherein, before step e), finish machining is also carried out of the end of the pipe to form a chamfer allowing receiving a weld bead during step e) of end-to-end assembly by welding;
wherein the pipe element obtained in step 1) and useful in step 2) comprises:
a layer of corrosion-resistant steel alloy on a terminal part of length L 1 of the internal wall of said pipe element from the first end to be welded;
a protective coating of plastic material applied directly on the internal wall of said pipe element; and covering a first part of length L 2 of said layer of corrosion-resistant steel alloy, a second part of length L 3 of said layer of corrosion-resistant steel alloy on the side of said first end to be welded of said pipe element not being covered by said protective coating of plastic material,
a compression ring of corrosion-resistant steel alloy inserted inside the pipe element comprising:
(i) a first annular part of length L 4 comprising an outer side face which is corrugated, over a part at least of its length L 4 , said first annular part being crimped against the pressure side face of at least one terminal part of said protective coating of plastic material covering said first part of said layer of corrosion-resistant steel alloy, and
(ii) a second annular part of length L 5 less than L 3 , continuing said first annular part, applied against a part of said second part of the layer of corrosion-resistant steel alloy not covered by said coating of plastic material, said second annular part of said compression ring extending from and against the

Assignees

• Saipem Sa

Inventors

• Hallot Raymond

Classifications

• B23K2101/10

  Pipe-lines · CPC title

• F16L58/1018

  the protective layer being fixed by means of anchoring devices · CPC title

• F16L1/26

  Repairing or joining pipes on or under water · CPC title

• F16L58/1009

  the coating being placed inside the pipe · CPC title

• F16L1/161

  the pipe being composed of sections of short length · CPC title