Radially outward orbital welding technique as a joining method used for inner tube to fitting connections in double wall tube configurations

Patent metadata

Field	Value
Publication number	US-2020384584-A1
Application number	US-201916433389-A
Country	US
Kind code	A1
Filing date	Jun 6, 2019
Priority date	Jun 6, 2019
Publication date	Dec 10, 2020
Grant date	—

Abstract

A process of welding fittings to ends of a double wall pipe comprising forming a first welded joint between an inner pipe and an inner receiver of a first fitting; forming a second welded joint between an outer pipe and an outer receiver of the first fitting; forming a third welded joint between the outer pipe and an outer receiver of a second fitting; and forming a fourth welded joint between the inner pipe and an inner receiver of the second fitting.

First claim

What is claimed is:

1 . A process of welding fittings to ends of a double wall pipe comprising:
forming a first welded joint between an inner pipe and an inner receiver of a first fitting; forming a second welded joint between an outer pipe and an outer receiver of said first fitting; forming a third welded joint between said outer pipe and an outer receiver of a second fitting; and forming a fourth welded joint between said inner pipe and an inner receiver of said second fitting.

2 . The process according to claim 1 , wherein said fourth welded joint comprises a welded lap fillet joint or a full penetration groove welded joint.

3 . The process according to claim 1 , further comprising:
placing an assembly of said second fitting and said inner pipe and outer pipe into a fixture; said fixture comprising:
a set of collets configured to retain said assembly of said second fitting and said inner pipe and outer pipe;
a backing plate coupled to said set of collets, said backing plate being fluidly coupled to said second fitting; and
a conduit fluidly coupled to said backing plate;
said conduit configured to fluidly couple a gas source to said backing plate.

4 . The process according to claim 3 , wherein said gas source comprises an inert shielding gas, further comprising:
flowing the inert shielding gas through the conduit to a groove formed in said backing plate; flowing the inert shielding gas from said groove through said second fitting into a chamber formed between said inner pipe and said outer pipe to protect said fourth welded joint.

5 . The process according to claim 1 , further comprising:
installing said fixture within an orbital welding device; and aligning a welding electrode with said inner pipe and an inner receiver of said second fitting.

6 . The process according to claim 3 , further comprising:
clamping said assembly of said second fitting and said inner pipe and outer pipe in a biasing member formed by said set of collets and said backing plate.

7 . The process according to claim 1 , further comprising:
sealing said fourth welded joint between said inner pipe and an inner receiver of said second fitting by using an arc energy to melt either a full or a partial thickness of the fitting with the inner pipe.

8 . A welding fixture comprising:
a set of collets configured to retain an assembly of a second fitting and an inner pipe and an outer pipe; a backing plate coupled to said set of collets, said backing plate being fluidly coupled to said second fitting; and a conduit fluidly coupled to said backing plate; said conduit configured to fluidly couple a gas source to said backing plate.

9 . The welding fixture according to claim 8 , further comprising:
a groove formed in said backing plate, said groove fluidly coupled to said conduit and fluidly coupled to said second fitting.

10 . The welding fixture according to claim 8 , wherein said fixture is configured to mount into an orbital welding device.

11 . The welding fixture according to claim 10 , wherein said orbital welding device includes a housing supporting an orbital welding head and adaptor configured to mount a welding electrode proximate an inner diameter of a joint between said inner pipe and an inner receiver of said fitting.

12 . The welding fixture according to claim 11 , wherein said welding electrode is configured to form a welded lap fillet joint between said inner pipe and said inner receiver of said fitting.

13 . The welding fixture according to claim 12 , wherein said welding electrode is positioned relative to said inner pipe inner diameter and configured for making a radially outward weld in a gap between the inner pipe and the fitting, wherein said gap is sealed by melting either a full or a partial thickness of the fitting with the inner pipe.

14 . A process of joining a double walled pipe with a fitting comprising:
placing an assembly of a fitting and an inner pipe and an outer pipe into a fixture, wherein said fitting and said outer pipe have a first welded joint; mounting said fixture into an orbital welding device; positioning a welding electrode relative to an inner diameter of said inner pipe proximate an inner receiver of said fitting; and forming a second welded joint between said inner pipe and said inner receiver.

15 . The process of claim 14 , wherein said second welded joint is formed with a radially outward weld in a gap between the inner pipe and inner receiver of the fitting.

16 . The process of claim 14 , wherein said second welded joint comprises a welded lap fillet joint or a full penetration groove welded joint.

17 . The process of claim 14 , wherein said fixture comprises:
a set of collets configured to retain said assembly of said fitting and said inner pipe and outer pipe; a backing plate coupled to said set of collets, said backing plate being fluidly coupled to said fitting; and a conduit fluidly coupled to said backing plate; said conduit configured to fluidly couple a gas source to said backing plate; flowing the inert shielding gas through the conduit to a groove formed in said backing plate; and flowing the inert shielding gas from said groove through said fitting into a chamber formed between said inner pipe and said outer pipe to protect said second welded joint.

18 . The process of claim 14 , further comprising:
making said second weld as a radially outward weld in a gap between the inner pipe and the inner receiver of the fitting, wherein said gap is sealed by melting either a full or a partial thickness of the inner receiver of the fitting with the inner pipe.

19 . The process of claim 14 , wherein said second weld comprises one of an orbital welding technique or a manual gas tungsten arc welding technique.

Assignees

• United Technologies Corp

Inventors

• Kaniowski Pawel
• Kaczor Piotr
• Wozniak Robert
• Lin Wangen
• Sanchez Christopher A

Classifications

• B23K9/0026 Primary

  specially adapted for particular articles or work · CPC title

• B23K2101/04

  Tubular or hollow articles · CPC title

• B23K9/16

  making use of shielding gas · CPC title

• B23K9/0282

  for welding tube sections · CPC title

• B23K37/0276

  for working on or in tubes (B23K37/0211 takes precedence) · CPC title