Friction stir welded pipes

Patent metadata

Field	Value
Publication number	US-9341287-B2
Application number	US-201414187777-A
Country	US
Kind code	B2
Filing date	Feb 24, 2014
Priority date	Feb 24, 2014
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

Fluid conveying pipes and processes of forming such pipes using friction stir welding. The fluid conveying pipes are formed from a pipe section that includes a first barrel coaxially and concentrically disposed within a second barrel. The first barrel and the second barrel are each formed from one or more sections or plates where longitudinal extending facing edges of the plates are friction stir welded (FSW) together along a seam(s) that extends longitudinally from the first end to the second end thereof. A plurality of the pipe sections can be connected together end to end using circumferential FSW seams to form a pipe.

First claim

The invention claimed is:

1. A fluid conveying pipe, comprising:
a pipe section that includes:
a first barrel coaxially and concentrically disposed within a second barrel, the first barrel and the second barrel each including an interior surface, an exterior surface, a first end and a second end;
the interior surface of the first barrel forming a fluid passageway that extends along a longitudinal axis, and the exterior surface of the first barrel is spaced from the interior surface of the second barrel to form a gap therebetween;
a spacer disposed within the gap to space the first barrel from the second barrel; and
wherein each of the first barrel and the second barrel are formed from at least two plates, and further comprising a plurality of friction stir welded seams that extend from the first end to the second end of each of the first barrel and the second barrel, the plurality of friction stir welded seams connecting the at least two plates to one another to form the first barrel and the second barrel.

2. The fluid conveying pipe of claim 1 , wherein the first barrel and the second barrel are formed from aluminum, aluminum bronze, titanium, steel, copper and alloys thereof, or plastic.

3. The fluid conveying pipe of claim 1 , wherein the spacer comprises a foam material disposed within and substantially filling the gap between the first barrel and the second barrel.

4. The fluid conveying pipe of claim 1 , wherein the spacer comprises a plurality of spacer elements disposed in the gap, the spacer elements are circumferentially spaced from one another, and each spacer element is in contact with the exterior surface of the first barrel and the interior surface of the second barrel.

5. The fluid conveying pipe of claim 1 , wherein the first barrel and the second barrel are substantially cylindrical.

6. The fluid conveying pipe of claim 3 , wherein the foam material is open cell, syntactic foam or closed cell foam.

7. The fluid conveying pipe of claim 4 , further comprising one or more of air or other gases, and water or other near incompressible/incompressible fluid filling the gap, and the pipe section is buoyant.

8. The fluid conveying pipe of claim 1 , wherein the pipe section is formed from at least one extruded plate that defines at least a portion of the first barrel, at least a portion of the second barrel, and at least a portion of the spacer.

9. The fluid conveying pipe of claim 1 , further comprising two of the pipe sections connected to one another end to end so that the fluid passageways are coaxial to one another.

10. The fluid conveying pipe of claim 9 , wherein the two pipe sections are connected to one another by a connecting ring, the connecting ring has one end that is friction stir welded circumferentially to the first end of the first barrel and to the first end of the second barrel of a first one of the two pipe sections, and the connecting ring has an opposite end that is friction stir welded circumferentially to the second end of the first barrel and to the second end of the second barrel of a second one of the two pipe sections.

11. The fluid conveying pipe of claim 10 , wherein the connecting ring is configured to allow the two pipe sections to flex relative to each other.

12. The fluid conveying pipe of claim 10 , wherein the connecting ring has a radial thickness that is greater than a radial thickness of the two pipe sections measured between the interior surface of the first barrel and the exterior surface of the second barrel.

13. The fluid conveying pipe of claim 10 , wherein:
for the first pipe section, the one end of the connecting ring is disposed between the first barrel and the second barrel at the first end thereof, there are first butt-lap joints between the one end and the first barrel and the second barrel, and the circumferential friction stir weld is at the first butt-lap joints; and
for the second pipe section, the opposite end of the connecting ring is disposed between the first barrel and the second barrel at the second end thereof, there are second butt-lap joints between the opposite end and the first barrel and the second barrel, and the circumferential friction stir weld is at the second butt-lap joints.

14. A method of forming a fluid conveying pipe, comprising:
forming a pipe section by:
forming an inner barrel and an outer barrel separately from one another by friction stir welding adjacent longitudinal edges on one or more plates to create on each of the inner barrel and the outer barrel a friction stir welded seam that extends longitudinally from a first end to a second end of each of the first barrel and the second barrel; and
the inner barrel and the outer barrel each include an interior surface and an exterior surface, and arranging the inner barrel coaxially and concentrically within the outer barrel with a gap therebetween, and providing a spacer in the gap that spaces the inner barrel from the outer barrel.

15. The method of claim 14 , comprising forming the pipe section by friction stir welding adjacent longitudinal edges on a plurality of extruded pipe segments, each extruded pipe segment includes inner walls, outer walls and the spacer integrally formed as a one-piece construction.

16. The method of claim 14 , wherein using a spacer to space the inner barrel from the outer barrel comprises disposing a foam material between the inner barrel and the outer barrel to substantially fill the gap between the inner barrel and the outer barrel.

17. The method of claim 14 , wherein using the spacer to space the inner barrel from the outer barrel comprises disposing a plurality of spacer elements between the inner barrel and the outer barrel, the spacer elements are circumferentially spaced from one another, and each spacer element is in contact with the exterior surface of the inner barrel and the interior surface of the outer barrel.

18. The method of claim 14 , comprising forming each of the inner barrel and the outer barrel from at least two plates; and for each of the inner barrel and the outer barrel, friction stir welding adjacent longitudinal edges of at least two plates to connect the at least two plates and create on each of the inner barrel and the outer barrel a plurality of friction stir welded seams that extend longitudinally from the first end to the second end of each of the inner barrel and the outer barrel.

19. The method of claim 14 , further comprising forming two of the pipe sections, and connecting the two pipe sections to one another end to end so that the fluid passageways are coaxial to one another.

20. The method of claim 19 , further comprising connecting the two pipe sections to one another by a connecting ring; friction stir welding one end of the connecting ring circumferentially to the first end of the inner barrel and to the first end of the outer barrel of a first pipe section of the two pipe sections, and friction stir welding an opposite end of the connecting ring circumferentially to the second end of the inner barrel and to the second end of the outer barrel of a second pipe section of the two pipe sections.

21. The method of claim 20 , wherein the connecting ring is configured to allow the two pipe sections to flex relative to each other.

22. The method of claim 20 , wherein:
for the first pipe section, disposing the one end of the connecting ring between the inner barrel and the outer barrel at the first end thereof, with first butt-lap joints between the one end and the inner barrel and

Assignees

• Lockheed Corp

Inventors

• Eller Michael R
• Brown Randy J
• Pham Duy N
• Jansen Eugene C
• Owen Trevor
• Miller Kevin

Classifications

• F16L59/143

  Pre-insulated pipes · CPC title

• B23K2101/06

  Tubes · CPC title

• F16L11/18

  Articulated hoses, e.g. composed of a series of rings · CPC title

• B23K20/129

  specially adapted for particular articles or work · CPC title

• F03G7/05

  Ocean thermal energy conversion, i.e. OTEC · CPC title