Positioning device for a fluid pipe and device for stopping the flow of a leak comprising same

Abstract

The invention relates to a positioning device (10) for a fluid pipe (11), the fluid pipe having a predetermined internal radius (R), the device being characterized in that it comprises: - a support tube (12) extending along a central axis; - at least two flexible strips (15) positioned outside the support tube and having two ends spaced apart along the axis of the support tube; - a means (16) for applying a force to each flexible strip along an axis parallel to a line between the ends of this flexible strip in order to bend this flexible strip; and - means for locking each flexible strip with respect to the support tube in a bending configuration obtained by applying the force, wherein: a first end of the strip is retained by a first locking means (13), a second end of the strip is retained by a second locking means (14), and an intermediate portion of the flexible strip is at a distance from the axis of the support tube at least equal to the predetermined radius.

Description

[0001] DESCRIPTION

[0002] TITLE OF THE INVENTION: POSITIONING DEVICE IN A FLUID PIPELINE AND LEAK-STOP DEVICE COMPRISING THEREOF

[0003] TECHNICAL FIELD OF THE INVENTION

[0004] The present invention relates to a positioning device in a fluid pipeline and a device for stopping a leak in a fluid pipeline incorporating this positioning device. It applies, in particular, to the positioning of an element in a gas pipeline, for example, the positioning of a sensor or a valve. It also applies to stopping the flow of gas in the event of a leak in the pipeline downstream of the stopping device. More specifically, the present invention applies to securing an existing natural gas delivery pipeline by inserting the stopping device into this pipeline upstream of a gas meter.

[0005] STATE OF THE ART

[0006] It is sometimes necessary to position a fixed instrument, such as a sensor, inside a fluid pipeline without opening the pipeline wall, for example, because it is buried. Furthermore, certain fluid distribution networks require specific safety measures, dictated by the nature of the fluid being transported and by potential risks of damage to the pipes that comprise these networks. For example, gas distribution networks in urban areas generally extend under roads and sidewalks, that is, under public infrastructure that may be subject to various interventions, including excavation work.

[0007] However, if a gas pipe is accidentally torn or cut during such an operation, the resulting gas leak immediately presents a high risk of fire or explosion.

[0008] In this context, safety valves have been developed to shut off gas pipelines as soon as an abnormally high gas flow is detected. Currently, however, safety valves can only be easily installed on new networks under construction, or possibly on existing networks, but only during their renovation. Indeed, because the pipelines of existing networks may have been built at different times and according to different standards, may not necessarily have precisely defined diameters, and / or may have obstacles, burrs, crushing, restrictions, and varying radii of curvature along their length, installing a safety valve in an existing network remains a delicate operation.The main difficulty in installing a shut-off device on an existing pipeline stems from the need to excavate to access the connection point and to create a pressurized seal to perform work on the connection when the gas is off. SUMMARY OF THE INVENTION.

[0009] The invention aims to overcome all or part of the drawbacks of the prior art. To this end, the present invention relates to a device for positioning a payload in a pipeline and an excess flow control device for stopping leakage in a fluid pipeline. These devices can be installed, without excavation, in most known fluid network pipelines, including pipelines with small radii of curvature, for example, on the order of ten times the diameter of the pipeline. The present invention also relates to a control device operating in circular cross-section pipelines with a bend radius within a predetermined range of values, and in pipelines that may be crushed and therefore have a substantially elliptical cross-section.The present invention also aims at a device configured to be inserted into a pipe by following its wall, even if the latter has obstacles, burrs, restrictions or bends.

[0010] The present invention relates, according to a first aspect, to a positioning device in a fluid pipeline of predetermined internal radius, which comprises:

[0011] - a support tube extending along a central axis,

[0012] - at least two flexible strips positioned outside the support tube and having two ends spaced apart along the axis of the support tube,

[0013] - a means of applying a force to each flexible strip along an axis parallel to a straight line between the ends of that flexible strip, in order to bend that flexible strip, and

[0014] - means for locking each flexible slat relative to the support tube in a flexural configuration obtained by applying said force, in which: a first end of said slat is held by a first locking means, a second end of said slat is held by a second locking means, and an intermediate part of said flexible slat is at a distance from the axis of the support tube at least equal to the predetermined radius.

[0015] Thus, in the absence of an external force on the positioning device, the blades are not compressed along the longitudinal axis of the support tube and have a configuration close to that of the support tube. Conversely, when an external force is applied to the positioning device, the flexible blades are compressed along the longitudinal axis of the support tube, deforming in bending such that their intermediate sections between their ends come into contact with the pipeline, and their ends are held in position by the locking means even in the absence of the external force on the positioning device.

[0016] Due to the frictional forces exerted by the intermediate sections of the flexible blades against the inner wall of the pipe, the entire device, along with its payload, is held in position within the pipe. This payload can be a sensor, for example, measuring the velocity, temperature, or pressure of a fluid flow within the pipe. Alternatively, it can be a valve that automatically closes when the fluid flow velocity exceeds a predetermined value.

[0017] In some embodiments, the means for applying a force comprises a ring that moves in translation on the outer wall of the support tube, this ring being supported on the second end of each flexible slat, said force being applied to the flexible slats via, on the one hand, the support tube and, on the other hand, this ring.

[0018] In some embodiments, the support tube has flexible blades extending opposite the first locking means, the second locking means comprising a radial extension of each flexible blade configured to extend behind the moving ring when the blades are in a flexed configuration.

[0019] In some embodiments, the second locking means includes a groove into which the second end of each slat enters when it is in a flexed configuration.

[0020] In some embodiments, the means for applying a force includes a spring mounted in tension or compression on the support tube, and held by a trigger, a force applied to the trigger causing it to move from a position in which it holds the spring to a position in which it releases the spring, the change in elongation of the spring then applying at least part of the force on the flexible strips parallel to a straight line passing through their ends.

[0021] In some embodiments, the middle part of each slat has a non-slip pad on its outer surface.

[0022] In some embodiments, the positioning device further includes a breaking element configured to apply an external force to the device and then to break when the two ends of the flexible slats are held by the two locking means.

[0023] In some embodiments, the positioning device further comprises a sleeve, a device in which each flexible slat is, before application of the force parallel to a straight line passing through its ends, held by a sleeve in a slightly flexed configuration in which its elasticity tends to deform it towards the flexed configuration, an external force to the device causing the displacement of the sleeve and the deformation of each flexible slat towards its flexed configuration under the action of its elasticity.

[0024] In some embodiments, the positioning device further comprises a sleeve and a fluid-tight lip seal, elastically deformable from a folded configuration, in which the lip seal is folded into the sleeve near the axis of the support tube, to an extended configuration, in the absence of the sleeve, in which the maximum radius of the lip seal is at least equal to the predetermined internal radius of the pipe. According to a second aspect, the present invention relates to a stop device comprising the positioning device of the invention, which stops a leak in the pipe when the fluid flow rate in the pipe exceeds a predetermined value. This stop device has an axis of rotational symmetry and comprises:

[0025] - the lip seal fixed hermetically to the outer wall of the support tube, such that, when the lip seal is in its deployed configuration, the only fluid passing through the stop device flows solely within the support tube, and

[0026] - a shutter opposite the upstream end of the support tube, held by a return means in a first position away from the upstream end of the support tube, this shutter offering a surface on which a drag force is exerted by the fluid flow along this shutter in this first position, the return means being configured so that, when the flow rate is less than the predetermined value, the shutter remains in the first position and, when the flow rate is greater than the predetermined value, the shutter moves to a second position in which the shutter obstructs the upstream end of the support tube, the pressure difference between the upstream and downstream of the device which corresponds to this flow rate greater than the predetermined value then retaining the shutter in the second position.

[0027] Thanks to these features, the shut-off device of the invention can be compact enough to be inserted, without excavation, into most known fluid network pipes, including pipes with small radii of curvature. The lip seal prevents fluid from escaping the support tube. Thanks to this lip seal, the device functions in circular pipes with a radius within a specified range, even if these pipes are compressed and therefore have an elliptical cross-section, with both the smaller and larger radii falling within this range.

[0028] When the fluid flow rate is lower than the predetermined value, the valve remains in the position where fluid flows through the support tube. However, when the fluid flow rate exceeds the predetermined value, particularly in the event of a significant leak in the pipeline downstream of the device, the valve moves to a second position where it blocks the upstream end of the support tube, thus preventing fluid flow from upstream to downstream of the device. The positioning device holds the shut-off device in position within the pipeline by ensuring that each intermediate section of the flexible blades is in contact with the inner wall of the pipeline.

[0029] Thus, in the event of a simultaneous sudden leak in the pipe downstream of the device and overpressure upstream, the "water hammer" caused by the closure of the valve cannot dislodge the stop device from the pipe wall, thereby ensuring that it maintains its function of sealing the pipe in the event of a leak. BRIEF DESCRIPTION OF THE FIGURES

[0030] Other advantages, purposes and features of the invention will become apparent from the following description, given for explanatory purposes only and in no way limiting the effect of the accompanying drawings, in which:

[0031] Figure 1 shows, in axial section, a first embodiment of the positioning device that is the subject of the invention, in a folded configuration within a pipe,

[0032] Figure 2 shows, in axial section, the positioning device illustrated in [Fig. 1], in its deployed configuration before removal of an insertion sleeve from the pipeline.

[0033] Figure 3 shows, in axial section, the positioning device illustrated in [Fig. 2], in its deployed configuration after removal of an insertion sleeve from the pipeline.

[0034] Figure 4 shows, in axial section, a first variant of the first embodiment of the positioning device, in its deployed configuration.

[0035] Figure 5 shows, in axial section, a second variant of the first embodiment of the positioning device, in its folded configuration.

[0036] Figure 6 shows, in axial section, a second embodiment of the positioning device that is the subject of the invention, in a folded configuration within a pipe.

[0037] Figure 7 shows, in axial section, the positioning device illustrated in [Fig. 6], in its deployed configuration.

[0038] Figure 8 shows, in partial axial section, an embodiment of a stop device of the invention, having flexible folded strips, and a device for installing the stop device in a pipe,

[0039] Figure 9 shows, in partial axial section, the stop device illustrated in [Fig. 8], featuring deployed flexible blades, and the device for installing the stop device in a pipeline.

[0040] Figure 10 shows, in partial axial section, the stop device illustrated in [Fig. 9], showing an unfolded lip seal, and the setting device being withdrawn,

[0041] Figure 11 shows, in exploded view, components of a particular embodiment of a stopping device that is the subject of the invention.

[0042] Figure 12 shows, in side view on its upper half and in cross-section on its lower half, the downstream part of a particular embodiment of a stop device of the invention, in its operating configuration before a leak occurs on the pipeline downstream of the stop device,

[0043] Figure 13 shows, in side view for the left part and in cross-section for the right part, a lip seal and a retaining ring of the downstream part of a particular embodiment of the stopping device which is the subject of the invention,

[0044] Figure 14 shows, in side view, a shutter guide of the upstream part of a particular embodiment of the stopping device that is the subject of the invention,

[0045] Figure 15 shows, in cross-section, the shutter guide illustrated in [Fig. 14]. Figure 16 shows, in perspective, a shutter seat of the stop device illustrated in [Fig. 11].

[0046] Figure 17 represents, in the form of a flowchart, the configuration and implementation steps of a stop device that is the subject of the invention in a pipeline.

[0047] DESCRIPTION OF IMPLEMENTATION METHODS

[0048] The following terms are used throughout the description:

[0049] - "upstream" the direction from which the fluid that passes through the device that is the subject of the invention originates,

[0050] - “downstream” the direction in which the fluid flows through the device that is the subject of the invention,

[0051] - “tube axis”, “device axis” or “central axis of the pipeline”, an axis of symmetry by rotation of the tube, device or pipeline, respectively, which are generally coincident once the device comprising the tube is positioned in the pipeline,

[0052] - "Free radial deployment configuration", a configuration in which each flexible component of the device extends radially,

[0053] - “radial deployment configuration in support”, a configuration in which each flexible component of the device extends radially until it contacts an internal wall of a predetermined pipeline,

[0054] - "Folded configuration", a configuration in which the flexible components of the device are folded by an insertion and implantation sleeve for the device in the predetermined pipeline, and

[0055] - “radial” a direction perpendicular to the axis of the device and passing through this axis.

[0056] We note, from the outset, that each of the figures 1 to 7 is not to scale but that each of the figures 8 to 16 is to scale, even if the scales of these different figures may be different.

[0057] In all the figures, the pipe in which the positioning or stopping device of the invention is positioned is cylindrical and has a circular guide of predetermined internal radius R. The positioning or stopping device is dimensioned according to this internal radius R.

[0058] In [Fig. 1], an axial section of a positioning device 10 is observed within a pipe 11. The positioning device 10 comprises a support tube 12, preferably cylindrical with a circular direction. The central axis of the support tube 12 (and of the device 10) is shown in Figures 1 to 10. In Figures 1 and 2, it coincides with the central axis of the pipe 11 to facilitate understanding of the positioning device's operation, as these axes coincide once the positioning device 10 is fixed to the pipe 11, as illustrated in [Fig. 3]. The support tube 12 has, on its external surface, a first locking means 13, in the form of a radial extension, preferably annular, extending beyond this external surface. In Figures 1 to 4, this first locking means 13 is positioned at the end of the support tube 12.Of course, the first locking means 13 can be positioned at other locations on this external surface and take other forms, for example, protruding lugs on the external surface of the support tube 12. The support tube 12 has, on its external surface, a second locking means 14, in the form of an annular groove formed in this external surface. Alternatively, at least one of the locking means is independent of the support tube 12.

[0059] Flexible strips 15 are located, in a sliding connection, on the external surface of the support tube 12. These flexible strips 15 thus have two ends that are far apart along the axis of the support tube 12. In a first implementation, these flexible strips 15 are independent of each other and guided by grooves (not shown) in the support tube 12. In a second implementation, the flexible strips 15 are held together by a clamping collar, for example, a circlip. In a third implementation, the flexible strips 15 are formed flat by stamping a sheet of metal, in conjunction with a circular mechanical connection between them. Then, the metal part containing these flexible strips and the mechanical connection is bent to assume a general cylindrical shape in which the free ends of the flexible strips are at a distance from the axis of this cylinder less than or equal to the distance between their connected ends.The free end of the flexible strips thus obtained can remain free or be retained with a circlip or weld onto a washer or ring. In a fourth implementation, the flexible strips 15 are cut flat and then joined, at least at one of their ends, by a ring crimped so as to enclose the flexible strips 15. In a fifth implementation, the flexible strips 15 are formed by linear cuts in a cylindrical tube of flexible material parallel to the axis of this tube.

[0060] It is noted that two wide flexible strips 15 (for example, with a width measured in a plane perpendicular to the axis of the support tube 12 between one third of the external diameter of the support tube and this external diameter) could suffice for positioning the device 10 in the pipe 11. However, preferably, the number of flexible strips 15 is at least three and, even more preferably, at least five.

[0061] A ring 16 is also mounted, in a sliding connection, on the support tube 12. This ring 16 is part of a means of applying a force on each flexible strip 15, by compressing each flexible strip 15 along an axis parallel to the axis of the support tube 12. As shown in [Fig. 2], under the action of a force 17 external to the device 10 (represented by an arrow in [Fig. 1]), the ring 16 slides towards the first locking means 13 and causes, firstly, the support of one end of the flexible slats 15 on the first locking means 13, then the application on each flexible slat 15 of a force parallel to a line passing through the ends of this flexible slat, and the bending of the flexible slats 15. A part of the flexible slats 15, intermediate part between their ends, comes into contact with the internal surface of the pipe 11.The force 17 then causes the deformation of this intermediate part so that the flexible strips 15 apply a radial force on the inner wall of the pipe 11, which ensures the existence of a static friction force retaining the device 10 in the pipe 11. Finally, the force 17 brings the end of each flexible strip 15 opposite the first locking means 13 to the side of the second locking means 14, in which this end becomes locked.

[0062] Each flexible slat 15 then finds itself in a flexed configuration, with:

[0063] - one end of the flexible strip 15 is held by the first locking means 13,

[0064] - a second end of the flexible strip 15 is held by a second locking means 14 and

[0065] - an intermediate part of the flexible slat 15 is at a distance from the axis of the support tube at least equal to the predetermined radius R, therefore in contact with the internal wall of a pipe of internal radius R if the positioning device is located in such a pipe.

[0066] As illustrated in [Fig. 3], ring 16 can then be removed.

[0067] Preferably, when folded onto the support tube 12, the flexible strips 15 exhibit a slight flex, slightly spreading their intermediate portions towards the inner wall of the pipe 11. This prevents the risk of the flexible strips 15 bending towards the support tube and then buckling under the action of the external force 17. This slight flex of the flexible strips in the folded state can be achieved during their manufacture. It can also be achieved by constraint within a sleeve, as explained below. It can also be achieved by a slight overthickness of the support tube 12 at the resting point of their intermediate portions. In embodiment 10, the second locking means 14 includes a groove into which the second end of each flexible strip 15 enters when it is in the flexed configuration.

[0068] As illustrated in [Fig. 4], in variant 18 of the device, the means for applying a force by compression comprises a spring 19 mounted in compression on the support tube 29, each end of which has a radial extension, preferably annular, and is held by a trigger (not shown). For example, this trigger is a pin, a movable rod radially protruding both inside and outside the support tube 29, this pin being able to be withdrawn by the action of a force external to the device 18. More generally, a force external to the device 18 causes the trigger to move from a position in which it holds the spring 19 in compression to a position in which it releases the spring 19.The spring 19 then lengthens and applies at least part of the compression force of the flexible slats 15 parallel to a straight line passing through their ends, causing them to bend, until their end opposite the first locking means 13 locks into the second locking means 14.

[0069] As illustrated in [Fig. 5], in variant 21 of the device, the means for applying a force by compression comprises a spring 19 mounted in compression on the support tube 29 and held by a trigger consisting of a clamp 25. This clamp 25 can be opened, as shown by the arrows, under the action of a force external to the device 21, to move the trigger from a position in which it holds the spring 19 compressed as illustrated in [Fig. 5] to a position in which the spring 19 is released. The spring 19 then extends and applies, on each flexible strip 15, at least a part of the compression force parallel to a straight line passing through the ends of this flexible strip 15, contributing to its bending, via a ring 28 mounted in a sliding connection on the support tube 29. The flexible strips 15 then take the configuration illustrated in [Fig. 5].2], In this variant, the second locking means consists of the spring 19 and the movable ring 28.

[0070] Of course, in other variants, a spring is mounted under tension on the support tube 29, for example between the flexible strips 15 and the support tube 29, and, after release by the trigger, causes the same flexion of the flexible strips 15.

[0071] In [Fig. 6], an axial section of a positioning device 20 is observed in the pipe 11. The positioning device 20 comprises a support tube 22. In this embodiment, the support tube 22 has flexible blades. As illustrated in [Fig. 6], these flexible blades are configured to flex towards the central axis of the device 20. The central axis of the support tube 22 (and of the device 20) coincides, in [Fig. 6], with the central axis of the pipe 11, for clarity, since these axes coincide once the positioning device 20 is fixed to the pipe 11, as illustrated in [Fig. 7]. The support tube 22 has, on its external surface, a first locking means 23, in the form of a radial extension, preferably annular, extending beyond this external surface. In figures 6 and 7, this first locking means 23 is positioned at the external end of the support tube 22 which does not have flexible blades.Of course, the first locking means 23 can be positioned at other locations on this external surface and take other forms, for example, protruding lugs on the external surface of the support tube 22. The support tube 22 has, on its external surface, a second locking means 24, in the form of radial extensions of the free ends of the flexible blades. Alternatively, at least one of the locking means is independent of the support tube 12.

[0072] Flexible slats 15 are located, in a sliding connection, on the external surface of the support tube 22. A ring 26 is mounted, in a sliding connection, on the flexible slats of the support tube 22. This ring 26 protrudes from the support tube 22 on the side opposite the first locking means 23. The ring 26 is part of a means for applying a force by compressing each flexible slat 15 along an axis parallel to the axis of the support tube 22. As shown in [Fig. 7], under the action of a force 27 (represented by an arrow in [Fig. 6]), the ring 26 slides on the flexible blades of the support tube 22 towards the first locking means 23 and causes, firstly, the support of one end of the flexible blades 15 on the first locking means 23, then, by application, on each flexible blade 15, of a force parallel to a line passing through its ends, the bending of each flexible blade 15.A portion of the flexible blades 15, the intermediate part between their ends, comes into contact with the inner surface of the pipe 11. The force 27 then causes deformation of this intermediate part so that the flexible blades 15 apply a radial force to the inner wall of the pipe 11, thus ensuring the existence of a static friction force retaining the device 20 in the pipe 11. Finally, the force 27 brings the end of each flexible blade of the support tube 22 beyond the ring 26. These flexible blades relax, and the second locking means 14, which includes the ring 26 and these flexible blades, blocks the end of each flexible blade 15 opposite the first locking means.

[0073] Each flexible lamella 15 is then found in a flexural configuration illustrated in [Fig. 7], in which:

[0074] - one end of the flexible strip 15 is held by the first locking means 23,

[0075] - a second end of the flexible blade 15 is retained by a second locking means comprising the ring 26 and the radial extensions 24 of the flexible blades of the support tube 22 and

[0076] - an intermediate part of the flexible slat 15 is at a distance from the axis of the support tube at least equal to the predetermined radius R, therefore in contact with the inner wall of a pipe 11 of internal radius R if the positioning device is located in such a pipe.

[0077] Of course, in variants similar to variants 18 and 21 illustrated in figures 4 and 5 for the first embodiment of the invention, a spring of the device 20 causes the application of a force parallel to a straight line passing through their ends on the flexible strips 15, after triggering by a trigger actuated by a force external to the device 20.

[0078] In embodiment 20, the support tube 22 has flexible blades extending opposite the first locking means 23, the second locking means having a radial extension 24 of each flexible blade configured to extend behind the movable ring 26 when the blades 15 are in a flexed configuration.

[0079] Thus, in the absence of a compressive force applied to the slats 15 parallel to a straight line connecting their ends, these slats 15 have a configuration close to that of the support tube. The positioning device is free to move within the pipe 11. Conversely, when a force is applied to the slats 15 parallel to a straight line connecting their ends, the flexible slats 15 are compressed along the longitudinal axis of the support tube, deforming in bending such that their intermediate portions between their ends come into contact with the inner wall of the pipe 11, and their ends are held in position by the locking means even in the absence of the force that caused the flexible slats 15 to bend.

[0080] Due to the friction forces of the intermediate parts of the flexible slats 15 bearing on the inner wall of the pipe 11, the entire device is held in position in the pipe, as well as the payload carried by this device.

[0081] This payload can be a sensor, for example, for measuring the speed, temperature, or pressure of a fluid flow within the pipeline. This payload can also be a valve that automatically closes when the fluid flow velocity inside the pipeline exceeds a predetermined value, as described opposite Figures 8 to 16.

[0082] In embodiments 10, 20 and 21, the means for applying a force by compression comprises a movable ring, 16, 26 or 28 respectively, in translation on the external wall of the support tube, 12, 22 or 29 respectively, this movable ring being supported on the second end of each flexible slat 15, the compression force of the slats parallel to a straight line connecting their ends being applied, on the one hand, to the support tube and, on the other hand, to this ring.

[0083] In some embodiments, the intermediate portion of each flexible strip 15 has a non-slip pad on its outer surface. This non-slip pad can be achieved by surface treatment and / or by the presence of a raised feature, for example, protrusions small enough to elastically deform the inner wall of the pipe 11 without damaging it.

[0084] In some embodiments (not shown), the positioning device includes a breaking element configured to apply external force to the device until the flexible slats reach their flexed configuration and then break when both ends of the flexible slats are held by the two locking means. For example, this breakage is achieved by pulling on a positioning rod of the positioning device with a tensile force exceeding the strength of a weak point in the breaking element.

[0085] In another example, the breaking element compresses the slats 15 under the action of the external force on the device until they reach their flexed configuration, then breaks when the two ends of the slats are held by the two locking means, for example, by increasing the external force to an intensity that causes the breaking point of the breaking element to rupture. For example, this breaking element is connected to a rod extending to an opening in the pipe 11, allowing the positioning device (and its payload) to slide into its operating location. This rod has a movable part, for example, a piston or a cable, which applies the external force to the positioning device.Once the configuration is deployed (figures 3, 4 or 7) and the ends of the flexible slats are held by the locking means, the increase in external force causes a break in the connection between the moving part and the positioning device, which allows the removal of the rod.

[0086] In some embodiments (not shown), each flexible strip 15 is, before the application of the external force to the device, compressed from a free configuration where it is radially deployed, to a folded configuration towards the external surface of the support tube. An external sleeve is then placed around these folded flexible strips 15 and retains them in the folded configuration. Within this sleeve, the elasticity of each flexible strip 15 tends to deform it towards the flexed configuration. The external force on the device causes the sleeve to move so that it no longer retains the flexible strips 15. The deformation of each flexible strip 15 then occurs towards its flexed configuration under the action of its elasticity.

[0087] This deformation can be accentuated by external force, for example via a spring in the device, as shown opposite [Fig. 4],

[0088] As described with the stop device, opposite Figures 8 to 16, in some embodiments, the positioning device may further include a lip seal, leak-proof to the fluid flowing in the pipeline, elastically deformable from a folded configuration within the sleeve, near the axis of the support tube, to a deployed configuration, in the absence of the sleeve, in which the maximum radius of the lip seal is at least equal to the predetermined internal radius R of the pipeline. This lip seal may be deployed simultaneously with the flexible strips, for example by being supported by these flexible strips, or independently, for example during the removal of a sleeve.

[0089] Figure 8 shows, in partial axial section, an embodiment of a stop device 30 of the invention comprising a positioning device 60 of the invention. In this initial configuration, the stop device 30 has been inserted into the pipeline 11 to its operating location. The positioning device 60 then has folded flexible blades 15. A positioning system 68 to 77 ensures the positioning of the stop device 30 by applying an external force to the positioning device 30, as illustrated in Figure 9, and is then removed from the pipeline 11, as illustrated in Figure 11.

[10] The positioning device 60 includes the support tube 62, the first locking means 63, the flexible slats 15 and the second locking means comprising the movable ring 65 mounted to slide on the support tube 62 and flexible slats of the support tube 62 terminating in radial extensions configured to retain the movable ring 65 in position, after the flexible slats 15 have been flexed (see [Fig. 9]). The positioning device 60 also includes a lip seal 40 mounted on the external surface of the movable ring 65. The movable ring 65 has, on its internal surface, a housing for an O-ring 66.

[0090] In addition to the positioning device 60, the leakage control device 30 for the fluid pipeline 11 comprises, successively from upstream to downstream of the fluid flow, an inlet nozzle 31, a shut-off spring 33, a shut-off guide 32, and a shut-off seat 34. A movable shut-off 35 carrying an O-ring 36 and positioned in the shut-off guide 32 is returned to this guide 32 by the shut-off spring 33. The characteristics and interactions of these components are detailed with reference to Figures 11 to 16.

[0091] The installation system includes a cylindrical sleeve 68 carrying a mechanism, 70, 72, 73 and 77, for pulling the flexible blades 64, on the one hand, and a rod 74 in which a cable 75 slides, on the other hand. The flexible blade traction mechanism 64 comprises plates 70, each having a curved groove 73 of constant width, in which slide lateral lugs 72 of a lever 77 whose free end has a radial extension configured to bear against an internal shoulder of the support tube 62 and retain the flexible blades 64. Initially, the sleeve 68 surrounds the lip seal 40. The sleeve 68 comprises an upstream flat annular partition 69 which is initially supported on the downstream face of the movable ring 65, an intermediate flat annular partition 71 which secures the traction mechanism to the sleeve 68 and a downstream annular partition secured to the ring 74, by means of a stop 76.

[0092] As illustrated in [Fig. 8], before the application of a force 67, the flexible strips 15 are held at their upstream ends by the first locking means 63 and, at their downstream ends, rest against the upstream face of the movable ring 65. Furthermore, the radial extensions of the levers 77 retain the flexible blades 64 of the support tube 62. Thus, the movements of the flexible rod 74 are transmitted to the positioning device 60, whether these movements are upstream or downstream of the pipe 11. The sliding of the flexible rod 74 thus allows the stopping device 30 to be precisely positioned in the pipe 11.

[0093] When the force 67 is applied by the flexible cable 75, this force 67 causes the sliding of the movable ring 65 to slide upstream, relative to the support tube 62 held by the radial extensions of the levers 77. This sliding of the movable ring 65 causes the flexible blades 15 to bend until they exert a radial force on the inner wall of the pipe 11, as illustrated in [Fig. 9]. Once the movable ring 65 has passed the radial extensions of the flexible blades 64, these spread apart, by elasticity, along the downstream face of the movable ring 65 and thus ensure the locking of the flexible blades 15 in the flexed configuration, by the second locking means.

[0094] Continued application of force 67 then causes, via the sliding of the lugs 72 in the groove 73, the levers 77 to pivot towards the central axis of the pipe 11 and the radial extensions of the flexible blades 64 to separate from the support tube 62, as illustrated in [Fig. 9]. By then pulling on the rod 74 downstream of the pipe 11, the sleeve 68 slides on the lip seal 40 until it moves away from it and allows its deployment to make watertight contact with the inner wall of the pipe 11. As illustrated in [Fig. 10], continued traction on the rod 74 allows it to be removed from the pipe 11.

[0095] Preferably, the O-ring 66 is located upstream of the entire length of the flexible blades of the support tube 62 once the stop device 30 is positioned in the pipeline, as shown in [Fig. 10]. This prevents fluid leakage between the flexible blades.

[0096] Figure 11 shows the main components of a shut-off device 30 and an arrow indicating the direction of fluid flow from upstream (right) to downstream (left). Along the axis of rotational symmetry illustrated in Figure 11, the following components are shown successively from upstream to downstream: an inlet nozzle 31, a valve spring 33, a valve guide 32, a valve seat 34, a positioning device 39 (only the support tube is shown, this tube forming a seal holder), a lip seal 40, and a retaining ring 41. Outside this sequence are a movable valve 35 and an O-ring 36. The characteristics and interactions of these components are detailed in Figures 11 to 16.Their dimensions are adapted for installation and operation in a pipeline of predetermined radius, in which a predetermined fluid, for example a gas, flows under a predetermined pressure, for example four or six bar.

[0097] The downstream portion of the shut-off device 30 is built on a positioning device and seal holder 39. The support tube of the positioning device 39 surrounds a central tubular channel with upstream and downstream ends open to the passage of fluid. This tubular channel of the positioning device 39 has a diameter configured so that the pressure drop due to the presence of the shut-off device 30 in the predetermined pipeline, under a minimum operating pressure, is less than one-quarter, and preferably one-sixth, of this minimum operating pressure. This low pressure drop thus allows two shut-off devices 30 to be installed one after the other in the pipeline in case the first one is defective. The lip seal 40 and the retaining ring 41 are fixed to the downstream end of the positioning device 39. The obturator seat 34 is fixed to the upstream end of the positioning device 39.The lip seal 40 serves to block the fluid flow across the entire radial section of the pipe to be protected, except for the radial section of the positioning device 39. In other words, the fluid passing through the stop device 30 flows through the tubular channel of the positioning device 39. The lip seal 40 also serves to center the downstream end of the positioning device 39 on the central axis of the pipe. The retaining ring 41 serves to stiffen the lip seal 40 and prevent it from inverting under the effect of overpressure in the pipe protected by the stop device, particularly when the movable obturator 35 blocks the upstream end of the positioning device 39, as explained below.

[0098] In one variant of the stop device, the respective positions of the lip seal 40 and the retaining ring 41, on the one hand, and the slats of the positioning device 39, on the other hand, are reversed. The support tube of the positioning device 39 then presents a stop on the external surface of its downstream end.

[0099] As illustrated in Figure 12, the upstream part of the stop device 30 is designed to allow the movable shutter 35 to block the upstream end of the positioning device 39 in the event of a leak downstream of the stop device 30.

[0100] The movable obturator 35 is located opposite the upstream end of the tubular channel. The movable obturator 35 is retained in the obturator guide 32 by a return means consisting of the spring 33, itself retained at its upstream end by a retaining ring 42 (not shown in Figure 11). The movable obturator 35 is then in its initial position away from the upstream end of the tubular channel.

[0101] The movable obturator 35, equipped with the O-ring 36, offers a surface on which the fluid flow along this obturator 35 in this first position exerts a drag force.

[0102] The head 351 of the shutter 35 extends a movable body 353 in the shutter guide 32. This guide 32 includes a return means, in this example consisting of the spring 33.

[0103] The return means 33 is configured so that, when the flow rate inside the pipe is less than a predetermined value, the movable obturator 35 remains in its first position. Conversely, when the flow rate in this pipe exceeds the predetermined value, the movable obturator 35 moves and provides a larger bearing surface for the fluid. It continues its movement until it reaches a second position in which the head 351 of this movable obturator 35 obstructs the upstream end of the tubular channel. This predetermined value is reached, in particular, when there is a significant leak in the protected pipe downstream of the shut-off device 30. For example, the predetermined value corresponds to a pressure difference between the upstream and downstream ends of the shut-off device 30 equal to half the upstream pressure.

[0104] The head 351 of the shutter 35 optionally has a through-opening 352 extending from a face facing the upstream end of the support tube 39 to a face facing the shutter guide. This through-opening 352 serves to automatically reset the shut-off device 30 when the downstream leak is repaired. Resetting consists of the body of the movable shutter 35 returning to its position inside the shutter guide 32 when the pressure difference between the upstream and downstream sides of the shut-off device 30 falls below a predetermined value that depends on the restoring force exerted by the restoring means 33. In some variants, the movable shutter 35 does not have this through-opening; an increase in pressure downstream of the shut-off device 30 must be manually performed by an operator to reset the device.

[0105] The pressure difference between the upstream and downstream sides of the shut-off device 30, corresponding to this flow rate exceeding the predetermined value, then holds the shutter in the second position. In practice, the pressure difference between the upstream and downstream sides is much greater than this predetermined value because, when the movable shutter 35 is closed, the downstream pressure is almost zero. As soon as this pressure difference returns to a value lower than a second predetermined value, for example, equal to the first predetermined value, the movable shutter 35 returns, under the effect of the return means 33, to its first position illustrated in Figure 12.

[0106] Figure 13 shows the lip seal 40 and the retaining ring 41. The lip seal 40 has a cylindrical peripheral portion 401 with a diameter equal to or slightly larger (for example, one to five percent larger) than the nominal diameter of the pipe to be protected. The lip seal 40 also has a cylindrical central portion 403 with a diameter equal to or smaller (for example, one to five percent smaller) than the diameter of the positioning device 39. The central portion 403 of the lip seal 40 is fixed in a watertight manner to the outer wall of the pipe channel. The lip seal 40 also has a conical portion 402 connecting the peripheral portion 401 and the central portion 403.

[0107] The lip seal 40 is fixed to the positioning device 39, which includes the tubular channel, abutting the outer annular stop of the annular channel. The lip seal 40 has an internal shoulder 404 near this stop, such that when the lip seal 40 is in a folded configuration (not shown) on the positioning device 39, this internal shoulder 404 surrounds the outer annular stop. This internal shoulder 404 allows the lip seal 40 to be compressed into a configuration where its outer surface is practically cylindrical, so that the fins 412 of the retaining ring 41 can bear against this cylindrical surface without undergoing irreversible deformation. The deployment of the lip seal 40 therefore occurs without deformation of the fins 412 after the stop device 30 is positioned in this pipeline.In Figure 13, the shoulder 404 has a flat, ring-shaped surface that bears against the stop and extends radially beyond it, thus reducing the thickness of the lip seal 40 at the end of this flat ring. A second portion of the shoulder 404 is conical and joins the internal conical surface of the upstream face of the lip seal 40.

[0108] The material constituting parts 401, 402, and 403 is elastically deformable from a folded configuration along the outer wall of the positioning device 39 to a free radial deployment configuration in which the maximum radius of the lip seal is at least equal to the radius of the predetermined pipeline. For example, the radius of part 401, measured from the axis of rotational symmetry of the stop device 30, is between one percent and five percent greater than the predetermined radius of the pipeline. The peripheral part 401 is sealed against the inner wall of the pipeline. Consequently, the only fluid passing through the stop device 30 flows within the tubular channel of the positioning device 39.

[0109] The retaining ring 41 has a cylindrical central portion 411 configured so that the downstream end of the positioning device 39 is crimped onto this central portion 411. It also has radial fins 412 extending from the central portion 411.

[0110] In the embodiment shown in Figure 13, the lip seal 40, in its free configuration, has a conical surface with its apex on the downstream side of the lip seal 40, the retaining ring 41 being positioned on the downstream side of the lip seal. Thus, the retaining ring 41 receives the lip seal 40 bearing on its radial fins 412. The conical shape of the lip seal 40 is therefore maintained even when the pressure difference is high between the upstream and downstream sides of the shut-off device 30. Furthermore, thanks to the orientation of the conical shape of the lip seal 40 and the fins 412, an increase in this pressure causes an increase in the bearing force of the periphery of the lip seal 40 on the inner wall of the pipe.

[0111] In some embodiments, the retaining ring 41 is crimped onto the positioning device 39 comprising the tubular channel. This type of fastening has the advantage of a small footprint and high mechanical resistance to pull-out.

[0112] Preferably, the thickness of the radial fins 412 of the retaining ring 41, measured perpendicular to the conical surface of the lip seal 40, is less than 0.3 mm. The fins 412 thus offer a good compromise between rigidity, to maintain the shape of the lip seal even in the event of a large pressure difference between the upstream and downstream sides of the stop device 30, and flexibility, allowing the radial fins of the retaining ring to fold parallel to the outer wall of the tubular channel.

[0113] It should be noted that, preferably, the fins 412 of the retaining ring 41 are connected to the lip seal 40 in such a way that they do not touch the inner wall of the pipe. In other words, the lip seal 40 extends radially beyond its connection with the end of the fins 412. This geometric feature ensures that it is the only lip seal 40 that bears against the inner wall of the pipe and thus ensures the watertightness of its connection with the pipe.

[0114] Figures 14 and 15 show a guide 32 for a shutter 35. This guide 32 has an upstream cylindrical external surface 321, followed by a toroidal surface 322, and then a conical surface 323. This conical surface 323 forms all or part of a fluid flow deflector configured to reduce the drag force exerted by the fluid on the shutter head. This deflector limits the entrainment of the movable shutter 35 by the fluid flow when the shutter 35 is in its first position described above with reference to Figure 12. Furthermore, thanks to this deflector 323, the fluid pressure loss due to the presence of the shut-off device 30 in the protected pipeline is reduced as long as the movable shutter 35 has not been triggered. On the downstream side, the guide 32 ends with a threaded cylindrical surface 324 for assembly with the obturator seat 34.

[0115] The fluid flow deflector reduces both the pressure loss between the upstream and downstream of the stop device 30, when the shutter 35 is open, and the instability of this shutter 35 which could be caused by turbulence near its head 351.

[0116] A groove 325 allows for a through thread 324. The shutter seat 34 can thus be screwed onto the shutter guide 32 bearing against the shoulder 326, a through thread 341 of the shutter seat 34 also being a through thread.

[0117] The shutter seat 34 illustrated in Figure 16 has a threaded upstream opening 341 configured to assemble onto the threaded surface 324 of the guide 32. The shutter seat 34 has, on its outer surface surrounding the opening 341, a conical surface 342 extending from the conical surface 323 of the guide 32, when the guide 32 and the shutter seat 34 are assembled, as illustrated in Figure 12. This conical surface 342 constitutes all or part of a flow deflector configured to reduce the drag force exerted by the fluid on the head 351 of the shutter 35.

[0118] Alternatively, only the shutter guide 32 or only the shutter seat 34 has a deflector. Thus, according to some embodiments, the shutter seat and / or the guide have, on their outer surface, a flow deflector configured to reduce the drag force exerted by the fluid on the shutter head.

[0119] Preferably, however, the flow deflector is supported by the shutter guide and the shutter seat. In the example shown, the deflector has a conical shape with its apex located in the shutter guide.

[0120] In this example, the apex angle 327 (see Figure 12) of the conical shape of the deflector is between 20 and 40 degrees. The inventor has determined that these values ​​of angle 327 prevent the occurrence of turbulence that could be detrimental to the operational stability of the obturator 35, while ensuring a low pressure drop due to the stop device 30. This low pressure drop thus makes it possible to place two stop devices 30 one after the other in the pipeline, in case the first one is defective.

[0121] This fluid flow deflector has, in the example shown, a maximum diameter greater than three-quarters of the diameter of the seal 36 of the obturator 35. A drag force is thus maintained on the head 351 of the obturator 35 which carries this seal 36, in order to cause, when the flow rate is greater than the predetermined value, the displacement of the obturator 35 to its second position in which the head 351 and the seal 36 of the obturator 35 obstruct the upstream end of the tubular channel.

[0122] The conical surface 342 has the same angle and functions as the conical surface 323. Downstream of the conical surface 342, the shutter seat 34 has three lateral openings 343 that allow the fluid to pass towards the upstream end of the positioning device 39. Three arches 344 separate these three lateral openings 343. The upstream faces 346 of the arches 344 extend, at a different apex angle, the conical surface 342 and help to limit the drag force exerted by the fluid on the head 351 and the seal 36 of the shutter 35. These arches 344 reduce the risk of turbulence occurring in the fluid flow surrounding the stop device 30. Finally, the shutter seat 34 has a downstream ring 345 configured to be screwed around the upstream end of the positioning device 39.

[0123] Figure 17 illustrates steps in a process 50 for manufacturing and installing the stop device 30 in a pipeline to be protected. In step 51, the parts of the stop device 30 are assembled as described above. In step 52, the lip seal 40, the retaining ring 41, and the flexible tabs of the positioning device 39 are compressed toward the axis of the stop device 30 to achieve a folded configuration. In step 53, the stop device 30 in its folded configuration is inserted into a cylindrical sleeve (not shown). In this folded configuration, the stop device 30 can move within a pipeline and follow its curves without damaging either the stop device 30 or the pipeline. In step 54, a housing (not shown) is mounted on the pipeline to be protected at the customer's control box.

[0124] In step 55, a rod is assembled to the sleeve, and the stop device 30 is inserted into the pipeline with this rod. In step 56, the stop device 30 is positioned back from a fork in the pipeline to be protected, for example, a fork connecting the pipeline to be protected to a larger supply pipeline. In step 57, the stop device 30 is removed from the sleeve by applying pressure to the rod to which the sleeve is attached. The lip seal 40, the retaining ring 41, and the flexible blades of the positioning device 39 then partially deploy to bear against the inner wall of the pipeline. In a step 58, the stop device 30 is tested by abruptly reducing the pressure downstream of this stop device 30 and verifying that the obturator 35 has triggered and closed the tubular channel of the positioning device 39.The shutter 35 is then re-engaged by restoring the pressure downstream of the stop device 30.

Claims

DEMANDS 1. A positioning device (10, 18, 20, 21, 60) in a fluid pipeline (11) of predetermined internal radius (R), characterized in that it comprises: - a support tube (12, 22, 29, 62) extending along a central axis, - at least two flexible strips (15) positioned outside the support tube and having two ends far apart along the axis of the support tube, - a means (16, 19, 26, 27, 28, 65) of applying a force to each flexible strip along an axis parallel to a straight line between the ends of that flexible strip, in order to flex that flexible strip, and - means for locking each flexible slat relative to the support tube in a flexural configuration obtained by applying said force, in which: a first end of said slat is held by a first locking means (13, 23, 63), a second end of said slat is held by a second locking means (14, 19, 24, 26, 28, 64, 65) and an intermediate part of said flexible slat is at a distance from the axis of the support tube at least equal to the predetermined radius.

2. Positioning device (10, 20, 60) according to claim 1, in which the means for applying a force comprises a ring (16, 26, 28, 65) movable in translation on the external wall of the support tube (12, 22, 62), this ring being supported on the second end of each flexible slat (15), said force being applied to the flexible slats by means of, on the one hand, the support tube and, on the other hand, this ring.

3. Positioning device (20, 60) according to claim 2, in which the support tube (22, 62) has flexible blades extending opposite the first locking means (23, 63), the second locking means comprising a radial extension (24, 64) of each flexible blade configured to extend behind the movable ring (26, 65) when the flexible blades (15) are in a flexed configuration.

4. Positioning device (10) according to any one of claims 1 or 2, wherein the second locking means has a groove (14) into which the second end of each flexible slat (15) enters when it is in a flexed configuration.

5. Positioning device (18, 21) according to any one of claims 1 to 4, wherein the force application means comprises a spring (19) mounted in tension or compression on the support tube (29), and held by a trigger, a force applied to the trigger causing it to move from a position in which it holds the spring to a position in which it releases the spring, the change in elongation of the spring then applying at least part of the force on the flexible slats (15) parallel to a straight line passing through their ends.

6. Positioning device (10, 18, 20, 21, 60) according to any one of claims 1 to 5, wherein the intermediate part of each flexible slat (15) has a non-slip pad on its external surface.

7. Positioning device (10, 18, 20, 21, 60) according to any one of claims 1 to 6, further comprising a breaking element configured to apply an external force to the device and then to break when the two ends of the flexible slats (15) are held by the two locking means.

8. Positioning device (10, 18, 20, 21, 60) according to any one of claims 1 to 7, further comprising a sleeve, in which each flexible slat (15) is, before application of force parallel to a straight line passing through its ends, held by a sleeve in a slightly flexed configuration in which its elasticity tends to deform it towards the flexed configuration, an external force to the device causing the displacement of the sleeve and the deformation of each flexible slat towards its flexed configuration under the action of its elasticity.

9. Positioning device (10, 18, 20, 21, 60) according to any one of claims 1 to 8, further comprising a sleeve and a lip seal (40) that is leak-proof against the fluid flowing in the pipeline (11), elastically deformable from a folded configuration, in which the lip seal is folded into the sleeve (68), near the axis of the support tube (62), to an deployed configuration, in the absence of the sleeve, in which the maximum radius of the lip seal is at least equal to the predetermined internal radius (R) of the pipeline.

10. A stop device (30) comprising the positioning device (10, 18, 20, 21, 60) according to claim 9, causing the stoppage of a leak in the pipeline (11) when the fluid flow rate in this pipeline exceeds a predetermined value, this stop device having an axis of rotational symmetry, this stop device comprising: - the lip seal (40) fixed hermetically to the outer wall of the support tube (12, 22, 29, 62), such that, when the lip seal is in the deployed configuration, the only fluid passing through the stop device circulates solely within the support tube, and - a shutter (35) opposite the upstream end of the support tube, retained by a return means (33) in a first position away from the upstream end of the support tube, this shutter offering a surface on which a drag force is exerted by the fluid flow along this shutter in this first position, the return means being configured so that, when the flow rate is less than the predetermined value, the shutter remains in the first position and, when the flow rate is greater than the predetermined value, the shutter moves to a second position in which the shutter obstructs the upstream end of the support tube, the pressure difference between the upstream and downstream of the device which corresponds to this flow rate greater than the predetermined value then retaining the shutter in the second position.

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