Hooped tube dimensioning method

• US 20030024628A1
• Filed: 07/25/2002
• Published: 02/06/2003
• Est. Priority Date: 08/01/2001
• Status: Active Grant

• Current Assignee: Institut Francais Du Petrole
• Original Assignee: Institut Francais Du Petrole
• Inventors: Guesnon, Jean, Gaillard, Christian
• Granted Patent: US 6,895,806 B2
• Time in Patent Office: Days
• US Class Current: 156/143
• CPC Class Codes: B29C 53/58 helically
• CPC Class Codes: B29C 63/10 around tubular articles
• CPC Class Codes: B29C 70/32 on a rotating mould, former or core
• CPC Class Codes: B29C 70/865 completely encapsulated
• CPC Class Codes: B29L 2023/22 Tubes or pipes, i.e. rigid bent tubes not for use as pipe couplings B29L2023/004
• CPC Class Codes: F16L 11/10 with reinforcements not embedded in the wall F16L11/11 takes precedence
• CPC Class Codes: Y10T 428/1393 Multilayer [continuous layer]

Abstract

A method of dimensioning a hooped tube intended to carry a fluid under pressure. The hooped tube consists of a metal tube and of a reinforcing element wound around the metal tube so as to hoop the tube. In a first stage, the method consists in determining, according to a first series of criteria, the characteristics of the metal tube without the hooping reinforcement that is wound around it at the end of the manufacture process. The first series of criteria includes the resistance to all the mechanical stresses applied to the hooped tube, i.e. compressive, bending, collapse and tensile stresses, with the exception of the radial stresses due to the internal pressure. In a second stage, the method consists in determining the hooping characteristics so as to obtain a determined prestress field in the wall of the hooped tube.

Claims

1. ) A method of dimensioning a hooped tube intended to carry a fluid under pressure, the hooped tube comprising a metal tube and a reinforcing element wound around said tube, the method comprising the following stages:

determining the material and the dimensions of said metal tube according to the mechanical stresses applied to said tube, with the exception of the radial stresses due to the internal pressure,

determining the tension T applied to the element during winding, and the number of winding layers n in order to obtain a determined prestress field in the wall of the hooped tube.

2. ) A method as claimed in claim 1, wherein T and n are so determined that the prestress field in the hooped tube is such that, at the working pressure, the stresses in said metal tube are less than two thirds of the yield limit of said metal tube and the tension in said element is less than one third of the rupture tensile strength of said element.

3. ) A method as claimed in any one of claims 1 and 2, wherein T and n are so determined that the prestress field in the hooped tube is such that, at the testing pressure, the stresses in said metal tube are less than the yield limit of said metal tube and the tension in said element is less than half the rupture tensile strength of said element.

4. ) A method as claimed in any one of the previous claims, wherein tension T is adjusted according to the winding diameter of the reinforcing element.

5. ) A method as claimed in any one of the previous claims, wherein the reinforcing element is made of carbon fibers coated with a polyamide thermoplastic material.

6. ) Application of the method as claimed in any one of the previous claims for manufacturing an auxiliary line element of a drilling riser element.

7. ) Application as claimed in claim 6, wherein said auxiliary line is one of the following lines:

kill line, choke line, booster line and mud return line.