Fittings with redundant seals for aircraft fuel lines, fuel tanks, and other systems

• US 7,533,850 B2
• Filed: 12/12/2005
• Issued: 05/19/2009
• Est. Priority Date: 06/09/2005
• Status: Expired due to Fees

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Shelly, Mark A., Van Kampen, Benjamin P., Carns, James A., Cutler, Theron L.
• Primary Examiner(s): Collins; Timothy D
• Application Number:
  US11/301,131
• Publication Number:
  US 20060278760A1
• Time in Patent Office: 1,254 Days
• Field of Search: 244/135.R, 244/135.A, 244/135.C, 244/136, 244/135.B, 285/136.1, 285/139.1, 285/139.2, 285/139.3, 285/204, 285/211
• US Class Current: 244/135.00R
• CPC Class Codes: B64D 39/06 Connecting hose to aircraft; Disconnecting hose therefrom
• CPC Class Codes: F16L 2201/30 Detecting leaks
• CPC Class Codes: F16L 39/005 for concentric pipes
• CPC Class Codes: F16L 5/06 by means of a swivel nut compressing a ring or sleeve
• CPC Class Codes: F16L 5/08 by means of axial screws compressing a ring or sleeve

Abstract

Fittings with redundant seals for aircraft fuel lines, fuel tanks, and other systems are disclosed. A fitting in accordance with one embodiment can be positioned adjacent to an aperture in a fuel tank wall having an inner surface and an outer surface. The fitting can include a first member having a flange and a barrel. The barrel can further include a passageway. A first flange seal can be positioned at a face of the flange and can be sealably coupled to a surface, for example, the tank wall. A second flange seal can be disposed outwardly from the first flange seal against the surface. The fitting can further include a second member (e.g., a sensor) positioned within the passageway of the barrel. The fitting can further include first and second barrel seals positioned between the barrel and the second member.

Claims

1. An aircraft system, comprising

a fuel tank having a tank wall with an inner surface, an outer surface, and an aperture extending from the inner surface to the outer surface;

and

a fluid-tight fitting positioned in the aperture, the fitting including;

a first member having a flange and a barrel, the flange being aligned generally parallel with the tank wall, the barrel having a first portion extending through the tank aperture and a second portion extending away from the tank, the barrel further having a passageway;

a fastener connected to the first portion of the barrel;

a first flange seal between the flange and the tank wall;

a second flange seal between the flange and the tank wall, the second flange seal being disposed generally radially outwardly from the first flange seal;

a second member positioned within the passageway of the barrel;

a first barrel seal positioned between the second member and barrel; and

a second barrel seal positioned between the second member and the barrel.

2. The system of claim 1 wherein the second member includes a sensor.

3. The system of claim 1 wherein the second member has an internal passageway coupled to the passageway of the barrel.

4. The system of claim 1 wherein the fluid-tight fitting is a first fluid-tight fitting, and wherein the fuel tank is coupled to a fuel line having an inner conduit and an outer conduit disposed outwardly from the inner conduit, and wherein the outer conduit has an outer conduit aperture, and wherein the system further comprises a second fluid-tight fitting in fluid communication with the outer conduit aperture, the second fluid-tight fitting having a barrel portion sealably coupled to the outer conduit with a third barrel seal and a fourth barrel seal.

5. The system of claim 4 wherein the second fluid-tight fitting includes a sensor, and wherein the sensor is in fluid communication with the outer conduit, but not the inner conduit.

6. The system of claim 1 wherein a potential leak path is located between the first member and the second member and wherein the first barrel seal is positioned at a first location along the potential leak path, with the second barrel seal positioned at a second location along the potential leak path, the second location being spaced apart from the first location, the second seal providing a redundant seal in the event of a failure of the first seal.

7. The system of claim 1, wherein:

the inner surface of the fuel tank is adjacent to an inner region of the fuel tank and the outer surface of the fuel tank is adjacent to an outer region of the fuel tank; and

the fastener is accessible from the inner region of the fuel tank, but not the outer region, and wherein the second member includes a pressure sensor accessible from the outer region of the fuel tank but not the inner region, the second member being removable from the first member from the outer region of the fuel tank, but not from the inner region.

8. The system of claim 1 wherein the first and second flange seals include O-rings disposed annularly relative to each other.

9. The system of claim 1 wherein the first and second barrel seals include O-rings disposed axially relative to each other.

10. An aircraft system, comprising:

an aircraft fuel line having an aperture and a flow axis generally transverse to the aperture at the aperture; and

a fluid-tight fitting positioned at the aperture, the fitting including;

a first member having a flange with a flange face, and a barrel with a passageway;

a first flange seal at the flange face, the first flange seal being positioned to sealably couple to a surface disposed generally radially outwardly from the aperture;

a second flange seal at the face of the flange, the second flange seal being disposed generally radially outwardly from the first flange seal and being positioned to sealably couple to the surface;

a second member positioned within the passageway of the barrel;

a first barrel seal positioned between the barrel and second member; and

a second barrel seal positioned between the barrel and the second member.

11. The system of claim 10 wherein a potential leak path is located between the first member and the second member and wherein the first barrel seal is positioned at a first location along the potential leak path, with the second barrel seal positioned at a second location along the potential leak path, the second location being spaced apart from the first location, the second seal providing a redundant seal in the event of a failure of the first seal.

12. The system of claim 10 wherein the fuel line includes an inner conduit positioned annularly within an outer conduit, and wherein the passageway of the barrel is in fluid communication with the inner conduit but not the outer conduit.

13. The system of claim 10 wherein the fuel line includes an inner conduit positioned annularly within an outer conduit, and wherein the passageway of the barrel is in fluid communication with the outer conduit but not the inner conduit.

14. The system of claim 10 wherein the second member positioned within the passageway of the barrel includes a sensor.

15. A method for installing a fluid fitting in an aircraft fuel system, comprising:

coupling a first member of a fluid fitting proximate to an aperture in a wall, the wall separating a first region from a second region, with the aperture extending through the wall from the first region to the second region, the wall being a wall of at least one of (a) an aircraft fuel tank and (b) an aircraft fuel line having a flow axis generally transverse to the aperture at the aperture;

securing the first member relative to the wall;

placing a flange of the first member proximate to the wall in the second region, with a first flange seal and a second flange seal positioned between the flange and the wall, the second flange seal being generally radially outwardly from the first flange seal;

inserting a second member of the fitting into a passageway of the first member, the passageway being in fluid communication with the first region; and

sealing an interface between the second member and the passageway with a first barrel seal and a second barrel seal.

17. The method of claim 15 wherein:

the wall includes a wall of a fuel tank, with the first region being within the fuel tank and the second region being external to the fuel tank;

securing the first member includes securing the first member from a position within the fuel tank;

sealing a flange includes sealing the flange with a first O-ring seal and a second O-ring seal positioned annularly outwardly from the first O-ring seal;

inserting a second member includes inserting a second member that includes a pressure sensor;

sealing an interface between the second member and the passageway includes sealing the interface with a third O-ring and a fourth O-ring spaced axially apart from the third O-ring along the passageway.

18. The method of claim 15 wherein coupling the first member includes coupling the first member to a fuel tank.

19. The method of claim 15 wherein coupling the first member includes coupling the first member to a fuel line.

20. The method of claim 15 wherein coupling the first member includes coupling the first member to a fuel line having an inner conduit and an outer conduit disposed annularly around the inner conduit, with the passageway being in fluid communication with the inner conduit but not the outer conduit.

21. The method of claim 15 wherein coupling the first member includes coupling the first member to a fuel line having an inner conduit and an outer conduit disposed annularly around the inner conduit, with the passageway being in fluid communication with the outer conduit but not the inner conduit.

22. The method of claim 15, further comprising sealing an interface between the flange and the wall with the first flange seal until the first flange seal fails, and sealing the interface between the flange and the wall with the second flange seal after the first flange seal fails.

23. The method of claim 15, further comprising sealing the interface between the second member and the passageway with the first barrel seal until the first barrel seal fails, and sealing the interface between the second member and the passageway with the second barrel seal after the first barrel seal fails.

16. The method of example 15, further comprising removing the second member of the fitting from the passageway without accessing the first region.