METAL PIPE, IN PARTICULAR PIPE FOR CONVEYING OIL AND GAS, COMPRISING A METAL COATING IN A TRANSITION REGION

Abstract

A metal pipe and a system of pipes, and a method of producing the same. The pipe is for conveying oil and gas. The pipe includes a metal coating in a transition region. The metal coating of the transition region obviates a subsequent coating of the inner surface of the transition region after connecting two pipes using a welding process in order to form a pipeline.

Claims

1. Metal pipe, in particular pipe for conveying oil and gas, comprising a pipe body (1) with an inner and outer surface (6, 7) and two pipe joints (3), a transition region (2) being arranged at the corresponding end of the pipe body (1) and the inner surface (6) of the pipe body (1) having at least a partial base coating (5) between the two transition regions, wherein the transition region (2) is coated on the inner surface (6) of the pipe body (1) with a weldable metal material with anti-corrosion and/or anti-abrasion properties, wherein the at least partial base coating (5) on the inside (6) of the pipe body (1) partially covers the metal coating (4) of the transition region (2), and wherein the base coating (5) is a sprayed-on metal base coating (5).

2. Metal pipe according to claim 1, characterized in that the metal coating (4) of the transition region (2) consists of a metal material, preferably of a weldable, stainless material, more preferably of the material 2.4856.

3. Metal pipe according to any of the preceding claims, characterized in that the metal coating (4) has a variable thickness (d) in the transition region (2), preferably a thickness (d) that increases toward the pipe joint (3).

4. Metal pipe according to any of the preceding claims, characterized in that the metal coating (4) in the transition region (2) has an average thickness (d) of 0.1 mm to 2 mm, preferably an average thickness (d) of 0.1 mm to 1 mm, even more preferably an average thickness (d) of 0.2 mm to 0.4 mm.

5. Metal pipe according to any of the preceding claims, characterized in that the pipe joint (3) has a coating (4) that is at least partially made of metal, preferably the pipe joint is made of the same material as the metal coating (4) of the transition region (2).

6-7. (canceled)

8. Metal pipe according to any of the preceding claims, characterized in that the length (L) of the pipe body (1) is greater than 10 m.

9. Metal pipe according to any of the preceding claims, characterized in that the pipe body (1) has an inner diameter (D) of more than 150 mm, preferably of more than 250 mm.

10-11. (canceled)

12. System of at least two metal pipes according to any of claim 1 to 5, 8, or 9, characterized in that: the metal pipes are connected to one another by a weld seam (10); and at least two pipes welded to one another have a continuous coating (4, 5) on the inner surface (6) with anti-corrosion and/or anti-abrasion properties.

13. System of at least two metal pipes according to claim 12, characterized in that the metal pipes are welded to one another by a weld seam (10) made from the metal coating material.

14. Method for producing a metal pipe according to any of claims 1 to 5, 8, or 9, a coating being applied multiple times to the inner surface (6) of the pipe body, characterized in that the transition region (2) of the pipe body (1) is coated with a metal material with anti-corrosion and/or anti-abrasion properties by means of build-up welding; and a base coating (5) is applied to the inner surface (6) of the pipe body (1), which covers the inner surface (6) of the pipe body (1) and partially covers the metal coating (4) of the transition region (2).

15. Method for producing a metal pipe according to claim 14, characterized in that a metal material, preferably a weldable, stainless material, more preferably the material 2.4856, is used for the metal coating (4) of the transition region (2).

16. Method for producing a metal pipe according to either claim 14 or claim 15, characterized in that a metal coating (4) is applied in the transition region (2) with a variable thickness (d), preferably with a thickness (d) that increases toward the pipe joint (3).

17. Method for producing a metal pipe according to any of claims 14 to 16, characterized in that the metal coating (4) is applied in the transition region (2) with an average thickness (d) of 0.1 mm to 2 mm, preferably with an average thickness (d) of 0.1 mm to 1 mm, even more preferably with an average thickness (d) of 0.2 mm to 0.4 mm.

18-24. (canceled)

25. Method for producing a metal pipe according to any of claims 14 to 17, characterized in that: a build-up weld is applied in the form of a ring in the as yet uncoated pipe at the pipe ends on the inside; the build-up weld has anti-corrosion and/or anti-abrasion properties; and the pipe is provided with the base coating material from the inside, with part of the build-up weld also being provided with the layer of the base coating in an overlapping manner.

26. Method for producing a system of at least two metal pipes according to any of claims 1 to 5, 8, or 9, characterized in that the pipe joints (3) are welded together, preferably with the material of the metal coating.

Description

[0028] The following four figures are attached to the description of the invention:

[0029] FIG. 1: Section through pipe with coating

[0030] FIG. 2: Section through pipe with coating of the pipe joint

[0031] FIG. 3: Section through pipe with coating in a recess

[0032] FIG. 4: Section through two connected pipes without a weld

[0033] FIG. 5: Section through two connected pipes with a weld seam

[0034] The invention is described in detail below with reference to the cited figures in the form of embodiments. In all figures, the same technical elements are denoted by the same reference signs.

[0035] FIG. 1 shows a section through a metal pipe according to the invention for the passage of oil or gas. The pipe body 1 consists for example of a carbon steel and forms the structure of the metal pipe. A transition region 2, which is provided with a metal coating 4, is arranged at the end of the pipe body 1. The metal coating 4 has a thickness d that increases toward the pipe joint 3. A base coating 5, in this case for example a plastics material layer, is applied to the inner surface 6 of the pipe body 1, the plastics material layer 5 partially covering the metal coating 4. The offset in the metal coating 4 allows for an almost edge-free inner surface 6 of the entire pipe.

[0036] FIG. 2 shows a section through a pipe with a metal coating 4 of the transition region 2 and an additional metal coating 4 of the pipe joint 3. The metal coating 4 is designed continuously so that an L-shape results in the sectional view. In the transition region 2, the metal coating 4 is designed to rise continuously to the pipe joint 3. The pipe joint 3 is coated with a constant thickness d. The inner edge 61 of the metal coating 4 is chamfered accordingly to form a partial V groove 8.

[0037] FIG. 3 shows a section through a pipe with a metal coating 4 of the transition region 2 in a recess 23 of the pipe body 1 and an additional metal coating 4 of the pipe joint 3. The metal coating 4 of the pipe joint and transition region 2 is designed to be continuous, so that an L-shape results in the sectional view. In the transition region 2, the base coating 5, in this case for example a sprayed-on metal coating, partially covers the metal coating.

[0038] FIG. 4 shows a section through two pipes according to the invention arranged next to one another. The two pipe joints 3 are in contact with one another, so that a continuous coating is formed. The chamfered edges of the metal coating 4 form a V groove on the inner and outer edges 61, 71. Furthermore, the mutually adjacent pipe joints 3 each have a complementary groove and spring connection 11, one part being coated or formed by the metal coating 4 of the pipe joint 3.

[0039] FIG. 5 shows the section from FIG. 3 with a corresponding weld seam 10 in the two V grooves 8 on the inner and outer edge 61, 71 for connecting the two pipes to form a pipeline.

TABLE-US-00001 TABLE 1 Reference signs Number Description  1 Pipe body  2 Transition region 21 Heat-affected zone 22 Coverage region 23 Recess  3 Pipe joint  4 Metal coating  5 Base coating  6 Inner surface 61 Inner edge  7 Outer surface 71 Outer edge  8 Part V groove  9 Part J groove 10 Weld seam 11 Groove and spring pipe body d Thickness L Length D Diameter