EP2156085A2

EP2156085A2 - Flexible piping with undulating pipe and external mechanical protection

Info

Publication number: EP2156085A2
Application number: EP08805647A
Authority: EP
Inventors: Caroline Ginter
Original assignee: TUBEST FLEXIBLE SOLUTIONS
Current assignee: BOA FLEXIBLE SOLUTIONS
Priority date: 2007-06-07
Filing date: 2008-06-04
Publication date: 2010-02-24
Also published as: WO2009004183A2; FR2917149B1; CN101680578A; WO2009004183A3; FR2917149A1

Abstract

The invention relates to a flexible piping (101) for conveying fluids, that comprises an inner undulated pipe (102) around which are provided a pressure resistance braid (109) having a tubular shape and made of an adapted material as well as an external mechanical protection (1 13) having a tubular shape. The flexible piping further includes an anti-abrasion sheath (1 17) provided around the external mechanical protection (1 13).

Description

Flexible tubing with corrugated pipe and external mechanical protection

The present invention relates to a flexible tubing used in the field of industry, particularly in the field of energy for the transport of dangerous fluids or not.

It is already known to equip including gas turbines with flexible pipes of this type. For this, each flexible tubing can simply be made of a flexible pipe inserted in a sheath made of stainless steel.

It has also been proposed a more elaborate flexible tubing having a reinforced protection against stresses exerted from the outside and likely to damage it. Such a flexible tubing is usually constituted by a corrugated pipe around which are successively connected, on the one hand, one or two tubular-shaped pressure-resistant braids made of stainless steel, and on the other hand, an external mechanical protection of also tubular shape.

According to an even more elaborate version of such a flexible tubing, described in the patent application FR 2,883,356 in the name of the applicant, a tubular-shaped anti-friction braid can be positioned between the corrugated pipe and the holding braid. pressure, and a damping sheath can be positioned between this pressure-resistant braid and the external mechanical protection.

When these tubings with external protection of the prior art are placed in a high vibration environment such as for example on a gas turbine, it was found that the external protection could quickly undergo some wear.

The present invention is intended to overcome this disadvantage.

This object of the invention is achieved with a flexible tubing intended for the transport of fluids, comprising an internal corrugated pipe around which are connected at least one tubular pressure-resistant braid made of a suitable material as well as external mechanical protection. of tubular form, remarkable in that it comprises an anti-abrasion sheath positioned around said external mechanical protection. Thanks to the presence of this abrasion-resistant sheath, this tubing can be installed in a high-vibration environment, such as a gas turbine, without the risk of abrasion of the mechanical protection by friction on neighboring organs such as other tubes. or fixed organs.

According to other optional features of the present invention:

said flexible tubing further comprises a tubular-shaped anti-friction braid positioned between said corrugated pipe and said pressure-holding braid, said anti-friction braiding being made of a suitable material whose hardness and / or coefficient of friction are lower than those of the material used to make the pressure-resistant braid; said flexible tubing further comprises a damping sheath positioned between said pressure-holding braid and said external mechanical protection;

said abrasion-resistant sheath is made of a material chosen from the group comprising coated fiberglass woven materials, braided PEEK materials, woven materials based on high-density polyamide fibers, Teflon-based materials formed ^® , Kevlar ^® based materials, silicone coated fiberglass knit materials;

said abrasion-resistant sheath is made of a material having resistance characteristics at a temperature greater than 125 ^° C., and preferably greater than 250 ^° C.

said abrasion-resistant sheath comprises an internal underlayer having good resistance to high temperatures, and an outer sub-layer having a high resistance to abrasion;

said internal underlayer is formed of a material chosen from the group comprising fiber materials based on glass fibers or basalt, these fibers possibly being in woven form, and metallic materials;

said outer sub-layer is formed of a material selected from the group consisting of coated fiberglass woven materials, braided PEEK materials, woven materials based on high-density polyamide fibers, Teflon-based materials formed ^® , Kevlar ^® based materials, silicone coated fiberglass knit materials; said abrasion-resistant sheath has a thermal insulation, preferably allowing a thermal gradient of 50 ^° C. between the external mechanical protection and the outside;

said corrugated pipe may comprise parallel or helical waves;

said corrugated pipe is made of a material chosen from the group formed by stainless steels and nickel base alloys;

said anti-friction braid is made of a material chosen from the group formed by cuprous alloys such as, for example, bronze, natural fibers and synthetic fibers;

each pressure-holding braid is made for example of stainless steel;

each damping sheath is made, for example, of a fiberglass braid or a silicone-coated fiberglass knit, or else another equivalent material;

- External mechanical protection consists of a stapled pipe made of stainless steel or other.

The invention will be better understood with the aid of the detailed description of two embodiments among the range of possibilities, description described below with reference to the appended figures in which:

- Figure 1 is an overall view of a flexible pipe according to a first embodiment of the invention, an end portion E is shown in section;

- Figure 1a is a partial view of the tubing of Figure 1, shown in broken view so as to highlight all the layers forming this tubing;

- Figure 2 is a longitudinal sectional view on a larger scale of the end portion E of Figure 1;

- Figure 3 is a sectional view along the line 3-3 of the flexible pipe shown in Figure 2;

FIG. 4 is a sectional view along the line 4-4 of the flexible tubing shown in FIG. 2, and

- Figures 5 to 8 are views similar to those of Figures 1a to 4 for another embodiment of the invention. Referring now to Figures 1 to 4, the tubing 1 is obtained from a corrugated pipe 2 with parallel waves 3 made of stainless steel and welded at each of its two ends to a connection 5.

An anti-friction braid 6, made of bronze for example, is then slid along the corrugated pipe 2, this anti-friction braid 6 being of tubular shape and having an internal diameter slightly greater than the largest diameter of the corrugated pipe 2, and a a length substantially equal to that of said corrugated pipe 2. More specifically, each of the two ends of the anti-friction braid 6 is crimped into a recess 7 presented by the corresponding connector 5 and is held in this position by means of a clamping collar 8 housed in the recess 7.

A pressure retaining braid 9 made for example of stainless steel or nickel base alloy is then slid along the anti-friction braid 6. This pressure retaining braid 9 is designed to have an internal diameter slightly greater than the outer diameter of the anti-friction braid 6, and a length substantially equal to that of the anti-friction braid 6. At each of the two ends of the pressure retaining braid 9 can be slipped a stop ring 1 1 said pressure retaining braid 9 and each retaining ring 11 can then be welded by means of a weld seam S to the outer lateral face of the corresponding connector 5.

A damping sheath 12, preferably made with a silicone-coated glass fiber knit, and having a thickness preferably between 3 and 4 mm, is then slid along the pressure-retaining braid. 9 so as to abut against the stop ring 1 1.

A mechanical protection, made in the form of a stapled pipe 13 of stainless steel provided with a catching ring 14 at each of its two ends, is slid around the damping sheath 12. More precisely, a ring of external stop 15 is threaded on each of the two ends of the stapled pipe 13, and the latter with its catching rings 14 is finally fixed by welding at each of its two ends to the stop rings 15 and to the external lateral face of the connectors 5 . An abrasion-resistant sheath 17 is then slid along the mechanical protection 13. A stop ring 19 set on each end of the sheath 17 makes it possible to fix this sheath on each connection 5.

In the context of the present invention, the term "anti-abrasion" means that the sheath 17 is able to withstand point mechanical contacts when subjected to a vibratory regime continuously and over a long period of time, such as is the case when the pipe 1 is installed on a gas turbine, where the vibrations generated by this machine are likely to rub the tubing 1 against other adjacent pipes or against fixed members of the machine: the standard service life Sheath 17 is a few years old and can go up to 10 years.

The abrasion-resistant cladding 17 may be braided fiber coated glass: This type of jacket is sold for example by the company FEDERAL MOGUL Systems Protection Group under the Bentley-Harris ^® brand - ThermoJacket ^® S. In addition to its excellent anti-abrasion properties such a jacket withstands a temperature of 550 ° C continuously and thermally insulates the stapled pipe 13 (thermal gradient of 50 ° C between the stapled pipe and the outside).

The anti-abrasion sheath 17 can also be braided with PEEK (polyaetheretherketone): this type of sheath is marketed for example by the company FEDERAL MOGUL Systems Protection Group under the brand Bentley-Harris ^® - Expando ^® PEEK. In addition to its excellent anti-abrasion properties, such a jacket withstands a temperature of 260 ^° C. continuously.

The abrasion-resistant sheath 17 can also be woven based on thick polyamide fibers: this type of sheath is marketed for example by FEDERAL MOGUL Systems Protection Group under the Bentley-Harris ^® - ProGard ^® brand. In addition to its excellent anti-abrasion properties, such a jacket withstands a temperature of 125 ° C continuously.

According to other possible embodiments, the abrasion-resistant cladding 17 may be formed based on Teflon ^®, Kevlar ^®, or of the same material as the damping sheath 12. As is known from the patent application FR 2 883 356, the wave tips 3 of the corrugated pipe 2 being placed in contact with the anti-friction braid 6 which is made of a material whose hardness and / or coefficient of friction are less than those of the material used to make the pressure-resistant braid 9, it follows that the phenomenon of wear is greatly reduced.

This is especially so since the damping sheath 12 minimizes the relative movements of the various components relative to each other due to the vibrational stresses to which the flexible pipe 1 is confronted. This sheath damps vibrations and therefore may in some cases prevent the resonance input of these components under the effect of these vibrations.

For example, it has been found that a flexible tubing 1 according to the invention equipped with such a combination "sheath (s) damping (s) / anti-friction braid" could have a service life of twenty times greater than that of flexible tubing traditionally used.

The abrasion-resistant sheath 17 makes it possible to avoid wear of the mechanical protection 13 under the effect of friction with members situated in the vicinity of the pipe 1.

This is particularly the case when the pipe 1 is installed on a gas turbine, the vibrations generated by this machine being capable of rubbing the pipe 1 against other adjacent pipes or against fixed members of the machine.

Note that in the particular case of the use of the tubing 1 for a gas turbine, the temperatures of the fluids circulating in this tubing can be high (typically of the order of 450 ⁰ C). The fact of using a sheath 17 resistant to high temperatures and especially for thermal insulation is then an advantage: it is then no longer necessary to use thermal protective mattresses, expensive and bulky, as is customary.

The embodiment of Figures 5 to 8 has a simplified structure compared to the previous embodiment.

The reference numerals similar to a hundred or so indicate bodies that are common to both embodiments.

The tubing 101 of this second embodiment comprises, from the inside to the outside: a corrugated pipe 102, a pressure-retaining braid 109, a stapled pipe 13, and an abrasion-resistant sheath 17.

The braid 109 is fixed on each connection 105 by a stop ring 11 1 and can be welded (weld S). The stapled pipe 1 13 is fixed on each coupling 105 by a stop ring 1 15 and the weld S.

The anti-abrasion sheath 1 17 is fixed on each coupling 105 by a stop ring 1 19.

In other words, this second embodiment differs from the previous one in that it does not comprise an anti-friction braid 6 or a damping sheath 12.

Of course, the present invention is not limited to the embodiments described and shown, provided as simple examples.

For example, the anti-abrasion sheath 17 (or 1 17) may comprise two sub-layers, namely an internal underlayer (that is to say, facing the mechanical protection 13 or 13). ) having good resistance to high temperatures, and an external underlayer having excellent abrasion resistance.

Such a solution with two sub-layers for the abrasion-resistant sheath makes it possible to combine the advantages attached to each of the materials forming these two sub-layers, and thus to choose an optimal material with respect to the constraints imposed (heat, temperature ) for each sub-layer.

For example, the inner underlayer may be formed of a fibrous material based on glass fibers or basalt, these fibers may be in woven form as a glass fabric.

This inner underlayer may also be formed in a metal sheet such as aluminum foil.

Ideally, the internal sub-layer may allow a thermal gradient of at least 50 ⁰ C between the stapled pipe 13 or 1 13 and the outer sub-layer.

The outer sub-layer may be formed for example in any one of the materials described above (coated fiberglass woven materials, PEEK braided materials, woven materials based on high-density polyamide fibers, formed materials based on Teflon ^® , Kevlar ^® based materials, silicone coated fiberglass knit materials, etc.)

The link between the inner sub-layer and the outer sub-layer can be achieved by coating or gluing. The two sub-layers could also be wound or threaded successively on the mechanical protection 13 or 1 13.

Claims

1.- flexible tubing (1; 101) for the transport of fluids, comprising an inner corrugated pipe (2; 102) around which at least one tubular-shaped pressure-retaining braid (9; 109) is made of a material adapted and an external mechanical protection (13; 13) of tubular form, characterized in that it comprises an anti-abrasion sheath (17; 1 17) positioned around said external mechanical protection (13; 13).

2. Flexible tubing (1) according to claim 1, characterized in that it further comprises a tubular-shaped anti-friction braid (6) positioned between said corrugated pipe (2) and said pressure-retaining braid (9). ), said anti-friction braid (6) being made of a suitable material whose hardness and / or coefficient of friction are lower than those of the material used to make the pressure-resistant braid (9).

3. Flexible tubing (1) according to one of claims 1 or 2, characterized in that it further comprises a damping sheath (12) positioned between said pressure-holding braid (9) and said mechanical protection external (13).

4. Flexible tubing (1; 101) according to any one of the preceding claims, characterized in that said abrasion-resistant sheath (17; 1 17) is formed of a material selected from the group consisting of woven fiberglass materials. coated glass, braided PEEK materials, woven materials based on polyamide fibers thick, materials formed based Téfloη ^®, materials formed on the basis of Kevlar ^®, knitting based materials coated glass fiber of silicone.

5. Flexible tubing (1; 101) according to any one of the preceding claims, characterized in that said abrasion-resistant sheath (17; 1 17) is formed of a material having a resistance at temperatures above 125 ° C. and preferably greater than 250 ^° C.

6. Flexible tubing (1; 101) according to any one of claims 1 to 3, characterized in that said abrasion-resistant sheath (17; 1 17) comprises an internal underlayer having good resistance to high temperatures, and an outer sub-layer having high abrasion resistance.

7. Flexible tubing (1; 101) according to claim 6, characterized in that said inner underlayer is formed in a material selected from the group consisting of fibrous materials based on glass fibers or basalt, these fibers may come in woven form, and metallic materials.

8. Flexible tubing (1; 101) according to one of claims 6 or 7, characterized in that said outer sub-layer is formed in a material selected from the group consisting of coated fiberglass woven materials, materials PEEK braided, woven materials based on polyamide fibers thick, the base materials formed of Teflon ^®, the materials based on Kevlar ^®, silicone-coated glass fiber knit-based materials.

9. Flexible tubing (1; 101) according to any one of the preceding claims, characterized in that said abrasion-resistant sheath has a thermal insulation, preferably allowing a thermal gradient of 50 ^° C between the external mechanical protection (13). 1 13) and the outside.

10. Flexible tubing (1; 101) according to any one of the preceding claims, characterized in that the corrugated pipe (2; 102) comprises waves (3; 103) parallel or helical.

1 1 .- flexible tubing (1; 101) according to any one of the preceding claims, characterized in that the corrugated pipe (2; 102) is made of a material selected from the group consisting of stainless steels and alloys base nickel.

12. Flexible tubing (1) according to any one of the preceding claims dependent on claim 2, characterized in that the anti-friction braid (6) is made of a material selected from the group consisting of cuprous alloys, natural fibers and synthetic fibers.

13. Flexible tubing (1; 101) according to any one of the preceding claims, characterized in that each braid of pressure resistance (9; 109) is made for example of stainless steel.

14. Flexible tubing (1) according to any one of the preceding claims dependent on claim 3, characterized in that each damping sheath (12) is made of a fiberglass braid or a fiber knit of silicone coated glass.

15. Flexible tubing (1; 101) according to any one of the preceding claims, characterized in that the external mechanical protection comprises a stapled pipe (13; 13) made of stainless steel or other.