Flexible conduit

• US 20040216795A1
• Filed: 03/10/2004
• Published: 11/04/2004
• Est. Priority Date: 04/30/2003
• Status: Active Grant

• Current Assignee: Nexans Incorporated (Nokia Corporation)
• Original Assignee: Nexans Incorporated (Nokia Corporation)
• Inventors: Lange, Stephan, Schippl, Klaus
• Granted Patent: US 6,840,284 B2
• Time in Patent Office: Days
• US Class Current: 138/112
• CPC Class Codes: F16L 59/125 Helical spacers
• CPC Class Codes: F16L 59/141 in which the temperature of the medium is below that of the ambient temperature rigid pipes of wood F16L9/006; vacuum insulation F16L59/065

Abstract

A flexible conduit for conveying cryogenic fluids has a metal inner tube and a metal outer tube. A strip-shaped spacer member is made of a material of low thermal conductivity, which is spirally wound on the inner tube such that it contacts both the inner and outer tubes. The strip-shaped spacer member is twisted about its own axis and includes a metal that is stable with respect to high-energy radiation and has a thermal conductivity of less than 25 W/m·K and a tensile strength of more than 240 MPa.

Claims

1. Flexible conduit for conveying cryogenic fluids, having a metal inner tube, and a metal outer tube, said flexible conduit comprising:

a strip-shaped spacer member made of a material of low thermal conductivity which is spirally wound on said inner tube such that said spacer member contacts both said inner tube and said outer tube wherein said strip-shaped spacer member is twisted about its own axis and includes a metal that is stable with respect to high-energy radiation and has a thermal conductivity of less than 25 W/m-K and a tensile strength of more than 240 MPa.

2. Flexible conduit in accordance with claim 1, wherein said spacer member includes titanium sheet.

3. Flexible conduit in accordance with claim 1, wherein said spacer member includes a nickel-base alloy that contains more than 15 wt. % chromium.

4. Flexible conduit in accordance with claim 1, wherein the width of said spacer member is 0.01-0.3 D, where D is the outside diameter of said inner tube.

5. Flexible conduit in accordance with claim 1, wherein the wall thickness of said spacer member is 0.001-0.03 D, where D is the outside diameter of said inner tube.

6. Flexible conduit in accordance with claim 1, wherein the length of lay of the twist is 3-10 D, where D is the outside diameter of said inner tube.

7. Flexible conduit in accordance with claim 1, wherein said inner tube is a corrugated stainless steel tube.

8. Flexible conduit in accordance with claim 1, wherein said outer tube is a corrugated stainless steel tube.