POSITIONING DEVICE IN A FLUID PIPELINE AND LEAK-STOPPING DEVICE COMPRISING IT

Abstract

TITLE OF THE INVENTION: POSITIONING DEVICE IN A FLUID PIPELINE AND LEAK-STOPPING DEVICE COMPRISING THEREOF. The positioning device (10) in a fluid pipe (11) of predetermined internal radius, comprising: - a cylindrical support tube extending along a central axis, - at least two flexible strips (15) outside the support tube, each having a free end, and - a means (18) for moving the free end of at least one flexible strip from the axis of the support tube, by applying an external moving force to this strip, from a folded configuration, in which the free end is at a distance from the axis of the support tube less than the predetermined internal radius, to an extended configuration, in which the free end of the flexible strip is at a distance from the axis of the support tube at least equal to the predetermined internal radius.and a means (18) for locking the free end of each flexible slat in the deployed configuration. Figure for the abstract: Figure 2,

Description

Title of the invention: POSITIONING DEVICE IN A FLUID PIPELINE AND LEAK-STOP DEVICE COMPRISING THEREOF Technical field of the invention

[0001] The present invention relates to a device for stopping a leak in a fluid pipeline. It applies, in particular, to stopping the flow of a gas in the event of a leak in the pipeline downstream of the stop device. More specifically, the present invention applies to securing an existing natural gas delivery pipeline by inserting the stop device into this pipeline upstream of a gas meter. State of the art

[0002] It is sometimes necessary to position a fixed instrument, for example a sensor, in a fluid pipe, without opening the wall of this pipe, for example because it is buried.

[0003] Certain fluid distribution networks justify special safety measures, imposed by the nature of the fluid transported and by possible risks of damage to the pipes of which these networks are made up.

[0004] For example, gas distribution networks in urban areas generally extend under roads and sidewalks, that is to say under works in the public domain which may be subject to various interventions, and in particular earthworks.

[0005] However, if a gas pipe is accidentally torn out or cut during such an operation, the resulting gas leak immediately presents a high risk of fire or explosion.

[0006] In this context, safety valves have been developed to shut off gas pipelines as soon as an abnormally high gas flow is detected. To date, however, safety valves can only be easily installed on new networks under construction, or possibly on existing networks, but only during their renovation. Indeed, since the pipelines of existing networks may have been built at different times and according to different standards, do not necessarily have diameters defined with very high precision, and 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 stems from the need to carry out excavation for access the connection point and perform a plugging operation under pressure to work on the connection without gas. Summary of the invention

[0007] 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 pipes with a radius within a range of radii, pipes which may be flattened and therefore have an elliptical cross-section, the small and large radii of which are within this range of radii.The present invention also aims at a device configured to be inserted into a pipe by following its wall, even if the latter presents obstacles, burrs, restrictions or bends.

[0008] According to a first aspect, the present invention relates to a positioning device in a fluid pipeline of predetermined internal radius, comprising: - a cylindrical support tube extending along a central axis, - at least two flexible strips on the outside of the support tube, each having a free end, and - a means for separating the free end of at least one flexible strip from the axis of the support tube, by applying an external separating force to this strip, from a folded configuration, in which the free end of the flexible strip is at a distance from the axis of the support tube less than the predetermined internal radius of the pipeline, to an extended configuration, in which the free end of the flexible strip is at a distance from the axis of the support tube at least equal to the predetermined internal radius of the pipeline, and - a means of locking the free end of each flexible slat in the deployed configuration.

[0009] In the deployed configuration, the free end of the flexible blades applies a static friction force to the inner wall of the fluid pipe, which has the effect of making the positioning device fixed to the pipe in translation and rotation. Due to these friction forces, the entire device, as well as the payload it carries, is held in position within the pipe.

[0010] This payload can be a sensor, for example, for the speed, temperature, or pressure of a fluid flow inside the pipe. This payload can also be a valve that automatically closes when the speed of the fluid flow inside the pipe exceeds a predetermined value.

[0011] In embodiments, the positioning device of the invention further comprises a sleeve for retaining flexible slats in the folded configuration, this sleeve constituting a part of the spacing means and applying said spacing force on said flexible slats, by its translation parallel to the axis of the support tube.

[0012] In embodiments, the sheath has radial through openings in which flexible strips slide during said translation of the sheath.

[0013] In embodiments, each flexible slat is part of a fan washer and has a fixed end relative to the support tube and a free end subjected to an elastic restoring force towards an intermediate configuration in which the free end of the flexible slat is at a distance from the axis of the support tube greater than the distance between the free end of said flexible slat and the axis of the support tube in the folded configuration, the spreading means being configured to spread this flexible slat from the intermediate configuration to the deployed configuration by bending this flexible slat and to apply a bending force to it around the point of contact of the spreading means with this flexible slat.

[0014] In embodiments, the sheath has a cylindrical shape with a generatrix parallel to the axis of the support tube, one of the edges of the sheath being in contact with flexible strips during said translation of the sheath.

[0015] In embodiments, the spreading means is configured to make the sleeve perform a first translation, prior to and in the opposite direction to the translation of the sleeve applying the spreading force to the flexible slats, the first translation bringing the sleeve to a position where it moves away from the flexible slats.

[0016] In embodiments, the spreading device of the invention further comprises a lip seal held compressed by the sleeve before the translation of the sleeve applying the spreading force to the flexible slats, said translation moving the sleeve away from the lip seal, this lip seal being configured to seal the channel between the support tube and the inner wall of the channel after the sleeve is moved away from this lip seal.

[0017] In some embodiments, the spreading means comprises a spring mounted in tension or compression on the support tube, and retained by a trigger, a external force to the device causing the trigger 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 spreading force on the flexible slats.

[0018] In embodiments, the free end of each flexible strip has a non-slip pad on its external surface.

[0019] In embodiments, the positioning device of the invention further comprises a breaking element configured to apply an external force to the device and then to break when the flexible slats are in the deployed configuration.

[0020] According to a second aspect, the present invention relates to a stop device comprising the positioning device that is the subject of the invention, causing the stoppage of a leak in the pipeline when the fluid flow rate in this pipeline exceeds a predetermined value, this stop device having an axis of rotational symmetry, this device comprising: - the lip seal fixed hermetically to the outer wall of the support tube, such that, when the lip seal is in the deployed configuration, the only fluid passing through the stop device flows solely within the support tube, and - a shutter opposite the upstream end of the support tube, retained by a return means in a first position away from the upstream end of the support tube, this shutter providing 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 sides of the device corresponds to this flow rate exceeding the predetermined value, thus holding the shutter in the second position.

[0021] 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 operates in circular pipes with a radius within a specified range, even if these pipes are slightly compressed and therefore have an elliptical cross-section, with both the smaller and larger radii within this range.

[0022] When the fluid flow rate is less than the predetermined value, the obturator remains in the position in which the fluid passes 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 in the pipeline from upstream to downstream of the device. The positioning device holds the shut-off device in position within the pipeline by ensuring that the free end of the flexible blades is in contact with the inner wall of the pipeline.

[0023] Thus, in the event of a simultaneous occurrence of a sudden leak on the pipe downstream of the device and an overpressure upstream, when the obturator is closed, the "water hammer" caused by this closure cannot cause the stop device to detach from the pipe wall, which ensures the preservation of its function of sealing this pipe in the event of a leak. Brief description of the figures

[0024] Other advantages, purposes and features of the invention will become apparent from the following description, given for explanatory purposes and in no way limiting the effect of the accompanying drawings, in which: [Fig. 1] represents, in side view on its lower half and in cross-section on its upper half, a first embodiment of a positioning device that is the subject of the invention in an initial folded configuration before deployment, [Fig.2] shows, in a side view of its lower half and in cross-section of its upper half, the positioning device illustrated in [Fig.1], in a final deployed configuration, [Fig.3] shows, in side view on its lower half and in cross-section on its upper half, a second embodiment of a positioning device that is the subject of the invention in an initial folded configuration, [Fig.4] shows, in side view of its lower half and in cross-section of its upper half, the device illustrated in [Fig.3] in an intermediate configuration, [Fig.5] shows, in side view of its lower half and in cross-section of its upper half, the device illustrated in [Fig.3] and in [Fig.4] in a deployed configuration, [Fig.6] shows, in side view on its lower half and in cross-section on its upper half, a third embodiment of a positioning device that is the subject of the invention in an initial folded configuration, [Fig.7] shows, in side view on its lower half and in cross-section on its upper half, the device illustrated in [Fig.6] in a deployed configuration, [Fig.8] shows, in exploded perspective, components of a particular embodiment of a stopping device that is the subject of the invention, [Fig.9] represents, 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 that is the subject of the invention, in its configuration deployed in support on the internal wall of a pipe of predetermined radius, [Fig. 10] represents, 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 deployed configuration before a leak occurs on the pipeline downstream of the stop device, [Fig. 1 1] 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, [Fig. 12] shows, in cross-section, a seal holder of the downstream part of a particular embodiment of the stopping device that is the subject of the invention, [Fig. 13] shows, in side view, a shutter guide of the upstream part of a particular embodiment of the stopping device which is the subject of the invention, [Fig. 14] shows, in cross-section, the shutter guide illustrated in [Fig. 13], [Fig. 15] shows, in perspective, a shutter seat of the stop device illustrated in [Fig. 8], and [Fig. 16] represents, in the form of a flowchart, the manufacturing, configuration and installation steps of a stop device that is the subject of the invention in a pipeline. Description of the implementation methods

[0025] Throughout the description, the following terms are used: - "upstream" the direction from which the fluid that passes through the device that is the subject of the invention originates, - “downstream” the direction in which the fluid flows through the device that is the subject of the invention, - “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, - “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, - "deployed configuration", a configuration in which the flexible components of the device are free from any contact with, or resting against, the inner wall of a predetermined pipe, and - “radial”, in a direction perpendicular to the axis of the device and passing through this axis.

[0026] It is noted from the outset that figures 1 to 7 are not to scale, but that each of figures 8 to 15 is to scale, even if the scales of these different figures may be different.

[0027] In all the figures, the pipe in which the positioning device 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.

[0028] A positioning device 10 is observed in [Fig. 1] within a pipe 11. The positioning device 10 comprises a support tube 12 (of which only a cross-section of one wall is shown in [Fig. 1]), preferably cylindrical with a circular direction. The central axis of the support tube 12 (and of the device 10) coincides, in Figures 1 to 7, with the central axis of the pipe 11, for clarity, since these axes coincide once the positioning device 10 is fixed to the pipe 11, as illustrated in [Fig. 2] and [Fig. 5].

[0029] The support tube 12 has, on its external surface, a first locking means 13, in the form of an annular radial extension extending beyond this external surface. The support tube 12 has, on its external surface, a second locking means, in the form of an annular radial extension formed within this external surface.

[0030] Flexible strips 15 have a free end, downstream (on the right in Figures 1 to 7) and a fixed end, upstream. In this embodiment, the flexible strips are part of a fan washer 16 which has a central annular portion fixed to the support tube 12 and the flexible strips extending in a star shape from the fixed portion.

[0031] Preferably, each flexible slat 15 is elastically deformable and has a fixed end relative to the support tube 12 and a free end subjected to an internal elastic restoring force towards an intermediate configuration close to or in contact with the internal wall of the pipe 11.

[0032] This fan washer 16 is preferably made by cutting and then folding a flat metal plate, which makes this fan washer 16 lose elasticity, then annealing each slat 15, which gives this slat 15 shape memory.

[0033] A sheath 18 surrounds at least part of each flexible lamella 15.

[0034] To insert the positioning device 10 into the pipe 11 without During excavation, each slat 15 of a fan washer 16 is compressed towards the axis of the support tube 12 with this sleeve 18. This compression allows the positioning device 10 to move inside the pipe 11 before its installation. even if the internal wall of this pipe 11 has obstacles, burrs, restrictions or bends.

[0035] In the embodiment shown in Figures 1 and 2, the sleeve 18 has lateral openings 19 for the passage of the flexible strips 15. These openings 19 are rectangular in shape, as shown in Figures 1 and 2, with their longer sides parallel to the axis of the positioning device. In alternative embodiments, the openings 19 have a different shape, for example, trapezoidal. Preferably, and as shown in Figures 1 and 2, the openings 19 have upstream and downstream edges with a beveled axial cross-section.

[0036] Under the action of a force 17, the sleeve slides in translation on the external surface of the flexible slats 15 towards their fixed end. Preferably, the flexible slats 15 have been constrained to enter the sleeve 18. In this case, during the translation of the sleeve 18, which increases the surface area of ​​the openings 19 opposite the flexible slats 15, the free ends of the flexible slats 15 move away from the support tube 12 due to elasticity.

[0037] Whether or not the flexible slats 15 have been pre-stressed in the sleeve 18, when the downstream edge of the openings 19 reaches the flexible slats 15 and continues its translational movement towards their fixed ends, the sleeve 18 causes the flexible slats 15 to spread apart. During this spreading, the free ends of the flexible slats 15 reach the inner wall of the pipe 11, as illustrated in [Fig. 2]. The continued translational movement of the sleeve 18 causes an internal bending force on the flexible slats 15 around their point of contact with the sleeve 18 and the application of a radial centrifugal force from the free ends of the flexible slats 15 on this inner wall of the pipe 11.

[0038] In embodiments such as that described in Figures 1 and 2, the support tube 12 also supports a lip seal 14. The lip seal 14 is leak-proof to the fluid flowing in the pipe 11 and elastically deformable from a folded configuration in the sleeve 18, near the axis of the support tube 12, to a deployed configuration, in the absence of the sleeve 18, in which the maximum radius of the lip seal 14 is at least equal to the predetermined internal radius of the pipe 11.

[0039] This lip seal 14 is initially compressed in the sleeve 18. During the translation of the sleeve 18, this lip seal 14 is released from this compression and unfolds until it seals the pipe 11 over its entire cross-section from the support tube 12 to the inner wall of the pipe 11. This lip seal 14 thus contributes to maintaining the position of the positioning device 10 by preventing a tilting during which its central axis would deviate from that of the pipe 11.

[0040] A positioning device 20 is observed in [Fig. 3] within a pipe 11. The positioning device 20 comprises a support tube 12 (of which only A cross-section of a wall is shown in [Fig. 3], preferably cylindrical with a circular directrix. The positioning device 20 has the same elements as the positioning device 10, except that the sleeve 28 does not have a lateral opening 19 and the flexible slats 25 are necessarily prestressed.

[0041] Under the action of an initial force 21, the sleeve 28 slides in translation downstream (to the right in Figures 3 to 5) until the slats 25 are released from its grip. Since the flexible slats 25 were constrained to enter the sleeve 18, due to elasticity, the free ends of the flexible slats 25 then move away from the support tube 12. The flexible slats 25 then assume an intermediate configuration, as illustrated in [Fig. 4]. In this intermediate configuration, their free end is at a distance from the axis of the support tube 12 that is less than, equal to, or greater than the predetermined radius R of the pipe 11. If the positioning device 20 is in such a pipe 11, the free ends of the flexible slats 25 are close to or in contact with the inner wall of the pipe 11.

[0042] When free from any external constraint, as in the intermediate configuration illustrated in [Fig. 4], each flexible strip 15 extends in a plane passing through the axis of rotational symmetry of the positioning device 10 and exhibits a radius of curvature from its base in contact with the fixed part of the fan washer 16 to its free end. Preferably, this radius of curvature varies by a multiplicative factor less than or equal to two, that is, the ratio of its maximum value to its minimum value is less than or equal to two. The radius of curvature preferentially increases from its minimum value to its maximum value, starting from the base of the flexible strip 15 towards its free end.

[0043] Thanks to its curvature, the flexible strip 15 can slide on an internal or external wall of a sheath 18.

[0044] In some embodiments, in its intermediate configuration, the radius of curvature of at least one flexible strip 15 is an increasing function of the distance to the axis of the support tube 12. This increase in the radius of curvature ensures that the bending resistance of each part of the strip increases with the moment of the static friction force exerted by the inner wall of the pipe 11 on that part of the strip. The retention capacity of the positioning device 10 in the pipe 11 is thus enhanced.

[0045] In some embodiments, in its intermediate configuration, the radius of curvature of at least one flexible slat 15 is a decreasing function of the width of this flexible slat 15, measured perpendicular to the plane passing through the axis of the support tube 12. This decrease ensures that the resistance of each part of the flexible slat 15 to bending increases with the moment of the friction force. static force exerted by the inner wall of the pipe 11 at this part of the slat. The retention capacity of the positioning device 10 in the pipe 11 is thus reinforced.

[0046] With the free end of at least one flexible slat 15 resting on the inner wall of the pipe 11 of predetermined radius R, the acute angle between the tangent to the slat 15 in the plane passing through the axis of rotational symmetry of the support tube 12 and the wall of this pipe 11 is preferably greater than 25 degrees.

[0047] Then, under the action of a force 22, in the opposite direction to the force 21, the sleeve 28 slides in translation upstream. When the upstream edge of the sleeve 28 reaches the flexible slats 25 and continues its translational movement towards the fixed ends of the flexible slats 25, the sleeve 28 amplifies the separation of the flexible slats 25.

[0048] During this separation, if the free ends of the flexible strips 25 were not already in contact with the inner wall of the pipe 11 in the intermediate configuration, these free ends of the flexible strips 25 reach the inner wall of the pipe 11, as illustrated in [Fig. 5]. The translational movement of the sleeve 28 after the contact of the ends of the flexible strips with the inner wall of the pipe 11 causes an internal bending force on the flexible strips 25 around the point of contact of the sleeve 28 and the application of a radial centrifugal force from the free ends of the flexible strips 25 on this inner wall of the pipe 11.

[0049] In embodiments such as that described in Figures 3 to 5, the support tube 12 also supports a lip seal 14. This lip seal 14 is initially compressed within the sleeve 28. During the upstream translation of the sleeve 28, this lip seal 14 is released from this compression and expands to seal the pipe 11 over its entire cross-section from the support tube 12 to the inner wall of the pipe 11. This lip seal 14 thus contributes to maintaining the position of the positioning device 20 by preventing a tilting during which its central axis would deviate from that of the pipe 11.

[0050] For the application of at least one of the forces 17, 21, and 22, the positioning device 10 or 20 may include at least one spring mounted in compression on the support tube 12. This spring may be held in compression by a trigger (not shown). For example, this trigger is a pin, a radially movable rod protruding inside and outside the support tube 12, this pin being able to be removed by the action of a force external to the device 10 or 20. More generally, a force external to the device 10 or 20 causes the trigger to move from a position in which it holds the spring in compression to a position in which it releases the spring. The spring then extends and applies at least part of the force that sets the sleeve 18 or 28 in motion.

[0051] Of course, in other variants, a spring is mounted under tension on the support tube 12, and, after release by the trigger, causes the same translation of the sheath 18 or 28.

[0052] Preferably, a second locking means (not shown) holds the sleeve 18 or 28 in contact with the flexible slats 15 or 25. A spring as described above can form this locking means. Alternatively, a flexible blade of the support tube 12, the free end of which has a radial extension, can be used to implement this second locking means. During upstream translation of the sleeve 18 or 28, this radial extension of the flexible blade engages with the downstream edge of the sleeve 18 or 28 and prevents it from moving backward.

[0053] Each flexible strip 15 or 25 is then found in a deployed configuration illustrated in [Fig.2] or [Fig.5], in which: - the fixed end of the flexible slat 15 or 25 is retained by the first locking means 13, - the free end of the flexible strip 15 or 25 rests against the inner wall of the pipe 11, and - an intermediate part of the flexible slat 15 or 25 is held in flexion by the second locking means comprising the sleeve 18 or 28.

[0054] A positioning device 23 is observed in [Fig. 6] within a pipe 11. The positioning device 23 comprises a support tube 27 (only a cross-section of one wall of which is shown in [Fig. 6]), preferably cylindrical with a circular direction. The positioning device 23 has the same elements as the positioning device 20, except that a helical spring 24 is positioned between the sleeve 28 and the support tube 27. Furthermore, this helical spring 24 is positioned, under compression, between the free ends of the flexible strips 25 and a stop 26 formed on the outer wall of the support tube 27.

[0055] Under the action of a force 29, the sleeve 28 slides in translation downstream (to the right in Figures 3 to 5) until the slats 25 are released from its grip. Since the flexible slats 25 were constrained to enter the sleeve 18, due to elasticity, the free ends of the flexible slats 25 then move away from the support tube 27. The flexible slats 25 then assume an intermediate configuration, as illustrated in [Fig. 4]. The spring 24 then relaxes and amplifies the separation of the flexible slats 25.

[0056] During this separation, if the free ends of the flexible strips 25 were not already in contact with the inner wall of the pipe 11 in the intermediate configuration, these free ends of the flexible strips 25 reach the inner wall of the pipe 11, as illustrated in [Fig. 7]. The translational movement of the sleeve 28 after the contact of the ends of the flexible strips 25 with the inner wall of the pipe 11 causes an internal bending force on the flexible strips 25. around the point of contact of the spring 24 and the application of a radial centrifugal force from the free ends of the flexible strips 25 on this inner wall of the pipe 11. The sleeve 28 can then be removed from the pipe 11. The spring 24 then constitutes the second means of locking the free ends of the flexible strips 25 against the inner wall of the pipe under bending stress.

[0057] In an alternative (not shown) to the third embodiment of the positioning device of the invention described opposite Figures 6 and 7, the spring 24 is replaced by a fan washer downstream of the fan washer 16, a cylindrical ring sliding both on the external walls of this additional fan washer, and on the internal walls of the fan washer 16. The flexible slats 25 of the fan washer 16 are thus pushed upstream by the additional fan washer, which applies to them the same bending force around the point of contact of the ring, as the force applied by the spring 24.

[0058] In this third embodiment, the spreading means comprises the spring 24 mounted under compression on the support tube 27, and retained by the sleeve 28 constituting a trigger. The action of the force 29, external to the device, moves this trigger from a position in which it retains the spring ([Fig. 6]) to a position in which it releases the spring ([Fig. 7]), the change in elongation of the spring 24 then applying at least part of the spreading force to the flexible slats 25.

[0059] In each of the embodiments presented above, in the absence of force exerted on the positioning device 10, 20 or 23, the slats 15 or 25 have a folded configuration close to the support tube 12 or 27. The positioning device 10, 20 or 23 is free to move in the conduit 11.Conversely, when a force 17, 29 or 21 then 22 is applied by means 18, 24 or 28 of spreading the free end of at least one flexible slat of the axis of the support tube, by application of an external spreading force to this slat, the flexible slats 15 or 25 deform in bending in such a way that their free ends come into contact with the inner wall of the pipe 11 and their fixed ends are held locked in position by the first locking means 13, their part in contact with the sleeve 18 or 28 being held, by the second locking means 18, 24 or 28 under bending stress even in the absence of the maintenance of an external force on the positioning device.This bending force on the flexible strips results from a force directed towards the inner wall of the pipe 11, exerted by the second locking means (generally comprising the spreading means 18, 24 or 28 and a stop for this spreading means) on the point of contact between this second locking means and the flexible strip, in a portion of the flexible strip intermediate between its ends. This bending force on the flexible strips. exerted by the second blocking means is represented by an oblique arrow in figures 2, 5 and 7.

[0060] Due to the friction forces of the free ends of the flexible slats 15 or 25 bearing on the inner wall of the pipe 11, the entire device 10, 20 or 23 is held in position in the pipe 11, as well as the payload carried by this device.

[0061] This payload can be a sensor, for example, for the speed, temperature, or pressure of a fluid flow inside the pipeline. This payload can also be a valve that automatically closes when the speed of the fluid flow inside the pipeline exceeds a predetermined value, as described opposite Figures 8 to 15.

[0062] In embodiments (not shown), the free end of each flexible strip 15 or 25 has a non-slip pad on its external 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.

[0063] In some embodiments (not shown), the positioning device 10 or 20 includes a breaking element configured to apply the external force to the device until the flexible slats 15 or 25 reach their deployed configuration and then to break when the flexible slats are held in this deployed configuration by the two locking means. For example, this breaking is achieved by pulling on a positioning rod of the positioning device with a tensile force exceeding the resistance of a weak point in the breaking element. This rod includes a movable part, for example a piston or a cable, which applies the external force to the positioning device 10 or 20. Once the deployed configuration of the flexible slats (Figures 2, 5, or 7) is achieved, the increase in the external force causes a connection between the movable part and the positioning device to break, thus allowing the rod to be withdrawn..

[0064] The positioning system for the positioning device 10 or 20 may include a cylindrical tube with the same internal and external radii as the sleeve 18 or 28, and a rod in which a cable and / or a piston slides. By acting on this cable or piston, the cylindrical tube of the positioning system pushes the sleeve 18 or 28 upstream for the application of one of the forces 17 or 22 and, if applicable, downstream for the application of force 21. The positioning system is then removed by simply sliding it out. In this case, the cylindrical tube of the positioning system replaces the sleeve 18 or 28 to compress the lip seal 14 and then release it when the positioning system is removed.

[0065] Figure 8 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 8, the following components are observed successively from upstream to downstream: an inlet nozzle 31, a shut-off spring 33, a shut-off guide 32, a shut-off seat 34, a spacer 38, a positioning device (of which only the support tube 39, which also serves as a seal holder, is shown), a lip seal 40, and a retaining ring 41. Outside this sequence are a movable shut-off valve 35, an O-ring 36, and a fan washer 37. The characteristics and interactions of these components are detailed in Figures 9 to 15.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.

[0066] As illustrated in [Fig. 9], the downstream portion of the shut-off device 30 is built on the support and seal-carrying tube 39. This support tube 39 includes a tubular channel 398 having upstream and downstream ends open to the passage of fluid. This tubular channel 398 of the support tube 39 has a diameter configured so that the pressure drop due to the presence of the shut-off device 30 in the predetermined pipeline 25, under a minimum operating pressure, is less than one-quarter, and preferably one-sixth, of this minimum operating pressure. This low pressure drop thus makes it possible to place two shut-off devices 30 one after the other in the pipeline 25 in case the first one is defective.

[0067] This support tube 39 carries an anchoring means configured to anchor the stop device 30 in the predetermined pipeline 25. In figures 8 to 15, a particular embodiment of this anchoring means consists of fan washers 37. The positioning device, which includes this anchoring means, can then be similar to one of the positioning devices 10 or 20 described above.

[0068] In [Fig.9], the downstream part is in deployed configuration, i.e. presents the deployment of the slats of each fan washer 37 which puts them in contact with the inner wall of a pipe 25 of predetermined radius R under the action of a spreading means and then a locking means in deployed configuration, as described opposite figures 1 to 7. Each fan washer 37 has the functions of centering the support tube 39 on the central axis of the pipe to be protected and of anchoring the stop device 30 on the inner wall of this pipe.

[0069] In this particular embodiment comprising three fan washers 37, this downstream portion includes, bearing against the upstream side of a stop 394 on the external surface of the support tube 39, a first spacer 38. A first fan washer 37 bears upstream on this first spacer 38. A second spacer 38 bears at The upstream side rests on this first fan washer 37. A second fan washer 37 rests upstream on this second spacer 38. A third spacer 38 rests upstream on this second fan washer 37. Finally, a third fan washer 37 rests upstream on this third spacer 38. The spacers 38 serve to position the fan washers 37 at a distance from each other and with an angular offset between them. These two spacings, axial on the one hand and angular on the other, facilitate the folding of their elastic fins 371 along the outer wall of the support tube 39 in the insertion sleeve, before its placement in the pipeline to be protected.

[0070] At the downstream end of the support tube 39, the lip seal 40 and the retaining ring 4L are fixed. At the upstream end of the support tube 39, the shut-off seat 34 is fixed. The lip seal 40 has the function of closing the fluid flow over the entire radial section of the pipeline to be protected except in the radial section of the support tube 39. In other words, the fluid that passes through the shut-off device 30 travels through the internal volume of the support tube 39. The lip seal 40 also has the function of centering the downstream end of the support tube 39 on the central axis of the pipeline. The retaining ring 41 has the function of stiffening the lip seal 40 and preventing it from turning around under the effect of overpressure in the pipe protected by the stop device 30, in particular when the movable obturator 35 comes to seal the upstream end of the support tube 39, as explained below.

[0071] As illustrated in [Fig.10], the upstream part of the stop device 30 is constructed to allow the movable obturator 35 to obstruct the upstream end of the support tube 39 in the event of a leak downstream of the stop device 30.

[0072] The movable obturator 35 is located opposite the upstream end of the tubular channel 398. 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 [Fig. 8]). The movable obturator 35 is then in its initial position away from the upstream end of the tubular channel 398.

[0073] The movable obturator 35, equipped with the O-ring 36, provides a surface on which the fluid flow along this obturator 35 in this first position exerts a drag force.

[0074] 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.

[0075] The return means 33 is configured so that, when the flow rate inside the pipe is less than a predetermined value, the movable shutter 35 remains in the first position. Conversely, when the flow rate in this pipe is greater than the predetermined value, the movable shutter 35 moves and offers a greater fluid support surface. So that it continues its movement until a second position in which the head 351 of this movable obturator 35 obstructs the upstream end of the tubular channel 398. This predetermined value is reached in particular when there is a significant leak on the protected pipeline 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.

[0076] The head 351 of the shutter 35 has a through opening 352 from a face oriented towards the upstream end of the support tube 39 to a face oriented towards the shutter guide.

[0077] This through-hole 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 embodiments, the movable shutter 35 does not have this through-hole; an increase in pressure downstream of the shut-off device 30 must necessarily be performed by an operator to reset the shut-off device 30.

[0078] 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 [Fig. 10].

[0079] In [Fig. 11], the lip seal 40 and the retaining ring 4L are shown. The lip seal 40 comprises a cylindrical peripheral portion 401, with a diameter equal to or slightly greater (for example, one to five percent greater) than the nominal diameter of the pipe to be protected. The lip seal 40 also comprises a cylindrical central portion 403, with a diameter equal to or lesser (for example, one to five percent less) than the diameter of the support tube 39. The central portion 403 of the lip seal 40 is fixed in a watertight manner to the outer wall of the tubular channel 398. The lip seal 40 further comprises a conical portion 402 connecting the peripheral portion 401 and the central portion 403.

[0080] The lip seal 40 is fixed to the support tube 39 having the tubular channel 398 abutting the external annular stop 392 of the annular channel. The lip seal 40 has an internal shoulder 404 near this stop 392, such that that, when this lip seal 40 is in a folded configuration (not shown) on the support tube 39, this internal shoulder 404 surrounds this external annular stop 392. This internal shoulder 404 allows the lip seal 40 to be compressed into a configuration where its external surface is practically cylindrical, so that the lamellae 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 lamellae 412 after the positioning of the stop device 30 in this pipeline 25. In [Fig. 11], the shoulder 404 has a flat ring-shaped surface, which bears against the stop 392 and extends radially beyond it, so that the thickness of the lip seal 40 is reduced at the end of this flat ring. A second part of the shoulder 404 is conical and joins the internal conical surface of the upstream face of the lip seal 40.

[0081] The material constituting parts 401, 402, and 403 is elastically deformable from a folded configuration along the outer wall of the support tube 39 to an extended configuration in which the radial extension of the lip seal is greater than the radial cross-section of the predetermined pipe 25. 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 pipe 25. The peripheral part 401 is pressed tightly against the inner wall of the pipe 25. Consequently, the only fluid passing through the stop device 30 flows within the tubular channel 398 of the support tube 39.

[0082] The retaining ring 41 has a cylindrical central portion 411 configured so that the downstream end of the support tube 39 is crimped onto this central portion 411. It also has radial slats 412 extending from the central portion 411.

[0083] At least one of the radial slats 412 has, in its deployed configuration, a general planar shape in a symmetrical trapezoid, the base of which is located on the central part 411. The radial extension of the slats 412 is, in the deployed configuration, equal to or greater than the radius R of the predetermined pipeline 25. For example, the radial extension of the slats 412 is, in this configuration, equal to or greater (for example, one to five percent greater) than the radius R of the pipeline 25 to be protected.

[0084] The free radial extension of the fins 412, equal to or greater than the predetermined radius of the pipe 25, ensures that the periphery of the lip seal 40 bears against the inner wall of the pipe 25 to be protected. In particular, the lip seal 40 alone, for example made of elastomeric material, cannot ensure a good seal against pressurized fluid when the diameter of the pipe 25 is not precisely defined, or when this pipe has an irregularity, a burr, a crushing or restriction. The retaining ring and its radial fins ensure better sealing of the lip seal in all these cases.

[0085] Thus, thanks to the lip seal 40 and the retaining ring 41, the stop device 30 operates in pipes 25 of circular cross-section having a radius within an extended radius range, pipes possibly crushed and consequently having an elliptical cross-section, the small radius and the large radius of which are within this extended radius range.

[0086] In embodiments, the radial extension of at least one slat 412 of the retaining ring 41, in the deployed configuration, is between one percent and five percent greater than the predetermined radius of the pipe 25. The bearing force of the periphery of the lip seal 40 on the inner wall of the pipe 25 is thus particularly high, and ensures a high seal of the junction of the lip seal 40 on the inner wall of the pipe 25.

[0087] In the embodiment shown in [Fig. 11], the lip seal 40 has, in free configuration, a conical surface whose apex is on the downstream side of the lip seal 40, the retaining ring 41 being positioned on the downstream side of the lip seal.

[0088] Thus, the retaining ring 41 receives the lip seal 40 bearing on its radial fins 412. The maintenance of the conical shape of the lip seal 40 is thus ensured even when the pressure difference is high between the upstream and downstream sides of the stop device 30. Moreover, 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 25.

[0089] In some embodiments, the retaining ring 41 is crimped onto the support tube 39 comprising the tubular channel 398. This type of fixing has the advantage of a reduced size and high mechanical resistance to pull-out.

[0090] 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, and flexibility allowing the radial fins of the retaining ring to fold parallel to the outer wall of the tubular channel.

[0091] It is noted that, preferably, the lugs 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 25. In other words, the lip seal 40 extends radially beyond its connection with the end of the lugs 412. This geometric feature ensures that it is the only lip seal 40 that bears against the inner wall of the pipe 25 and thus ensures the sealing of its connection with this pipe 25.

[0092] The support tube 39 illustrated in [Fig. 12] has a general cylindrical shape with a circular directrix perpendicular to the axis of the stop device 30. The interior of this support tube 39 constitutes the tubular channel 398 for the passage of the fluid. On the outer wall of this support tube 39, from upstream to downstream, there is an annular stop 394, which retains each fan washer 37 and each spacer 38. There is also an annular stop 392, similar to the annular stop 394, which retains the lip seal 40 and the retaining ring 4L. A zone 393 is located between the annular stops 392 and 394. The length of zone 393, measured parallel to the axis of the stop device 30, is such that the tabs 371 of the fan washers 37 and the lip seal 40 do not touch when they are folded along the outer wall of the support tube 39 for insertion into the pipeline to be protected.

[0093] A portion 391 of the support tube 39 is deformed during crimping to fix the seal 40 and its retaining ring 41 onto the support tube 39.

[0094] A chamfer 396 inside the support tube 39 extends the slope of the obturator seat 34 so as not to create a step for the flow and thus limit pressure losses.

[0095] An additional thickness 397, internal to the support tube 39, allows to give a little thickness to the wall of the support tube 39 to compensate for the material lost by the thread allowing the junction between this support tube 39 and the obturator seat 34.

[0096] Figures 13 and 14 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 constitutes all or part of a fluid flow deflector configured to reduce the drag force exerted by the fluid on the head of the shutter. 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 respect to [Fig. 10]. 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 is not triggered. On the downstream side, the guide 32 ends with a threaded cylindrical surface 324 for assembly with the obturator seat 34.

[0097] 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.

[0098] A groove 325 allows for a through thread 324. The shutter seat 34 can thus be screwed and tightened onto the shutter guide 32 bearing against the shoulder 326, a through thread 341 of the shutter seat 34 also being a through thread.

[0099] The shutter seat 34 illustrated in [Fig. 15] 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 [Fig. 10]. 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.

[0100] 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.

[0101] Preferably, however, the flow deflector is carried by the shutter guide and by the shutter seat. In the example shown, the deflector has a conical shape whose apex is located in the shutter guide.

[0102] In this example, the apex angle 327 (see [Fig. 10]) of the conical shape of the deflector is between 20 degrees and 40 degrees. The inventor has determined that these values ​​of angle 327 prevent the occurrence of turbulence detrimental to the operating 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 pipe 25, in case the first one is defective.

[0103] 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 398.

[0104] The conical surface 342 has the same angle and functions as the conical surface 323. Downstream of the conical surface 342, the obturator seat 34 has three lateral openings 343 that allow the fluid to pass towards the upstream end of the support tube 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 obturator 35. These arches 344 reduce the risk of turbulence occurring in the fluid flow surrounding the stop device 30. Finally, the obturator seat 34 has a downstream ring 345 configured to be screwed around the upstream end of the support tube 39.

[0105] Figure 16 illustrates steps in a process 90 for manufacturing and installing the stop device 30 in a pipeline 25 to be protected. In a step 91, the various parts of the stop device 30 are manufactured, with all or part of the technical characteristics described above. Preferably, during the manufacture of the fan washers 37, they are annealed.

[0106] In step 92, the parts of the stop device 30 are assembled as described above. In step 93, the lip seal 40, the retaining ring 41, and the fins 371 of the fan washer 37 are compressed toward the axis of the stop device 30 to achieve a folded configuration. In step 94, the stop device 30, thus folded, is inserted into a cylindrical sleeve, such as one of the sleeves 18 or 28. In this folded configuration, the stop device 30 can move within a pipeline and follow its curves without damaging the stop device 30 or the pipeline. In step 95, a housing (not shown) is mounted on the pipeline to be protected 25 at the customer's box.

[0107] In step 96, a rod is assembled to the sleeve, and the stop device 30 is inserted into the pipe 25 with this rod. In step 97, the stop device 30 is positioned back from a fork in the pipe to be protected 25, for example, a fork connecting the pipe to be protected 25 to a larger supply pipe. In step 98, the flexible blades are deployed under bending applied by the second locking means by applying pressure to a piston or pulling on a cable of the rod to which the device is attached. The lip seal 40, the retaining ring 41, and the blades of the fan washer 37 then bear against the inner wall of the pipe 25, for example, as shown opposite Figures 1 to 7.During a step 99, the installation system including the ring is removed and 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 398 of the support tube 39. The obturator 35 is then re-engaged by restoring the pressure downstream of the stop device 30.

Claims

Demands

1. A positioning device (10, 20, 23) in a fluid pipeline (11) of predetermined internal radius (R), characterized in that it comprises: - a cylindrical support tube (12, 27) extending along a central axis, - at least two flexible strips (15, 25) outside the support tube, each having a free end, and - a means (18, 24, 28) for moving the free end of at least one flexible strip away from the axis of the support tube, by applying an external separation force (17, 22, 29) to this strip, from a folded configuration, in which the free end of the flexible strip is at a distance from the axis of the support tube less than the predetermined internal radius of the pipeline (11), to an extended configuration, in which the free end of the flexible strip is at a distance from the axis of the tube support at least equal to the predetermined internal radius of the pipe, and - a means (18, 24,28) locking of the free end of each flexible slat in the deployed configuration.

2. Device (10, 20) according to claim 1, which further comprises a sleeve (18, 28) for retaining flexible slats (15, 25) in the folded configuration, this sleeve constituting a part of the spreading means and applying said spreading force on said flexible slats, by a translation parallel to the axis of the support tube (12).

3. Device (10) according to claim 2, wherein the sheath (18) has radial through openings (19) in which flexible strips (15) slide during said translation of the sheath.

4. A device (10, 20, 23) according to any one of claims 1 to 3, wherein each flexible slat (15, 25) is part of a fan washer (16) and has a fixed end relative to the support tube (12, 27) and a free end subjected to an elastic restoring force towards an intermediate configuration in which the free end of the flexible slat is at a distance from the axis of the support tube greater than the distance between the free end of said flexible slat and the axis of the support tube in the folded configuration, the spreading means (18, 24, 28) being configured to spread this flexible slat from the intermediate configuration to the deployed configuration and to apply a bending force around the point of contact of the spacing means with this flexible slat.

5. Device (20) according to any one of claims 2, 3 or 4 when it depends on any one of claims 2 or 3, wherein the sleeve (28) has a cylindrical shape with generatrix parallel to the axis of the support tube (12), one of the edges of the sleeve being in contact with flexible strips (25) during said translation of the sleeve.

6. Device (20) according to claims 4 and 5, wherein the spreading means is configured to make the sleeve (28) perform a first translation, prior to and in the opposite direction to the translation of the sleeve applying the spreading force to the flexible slats (15, 25), the first translation bringing the sleeve to a position where it moves away from the flexible slats (25).

7. Device (10, 20) according to any one of claims 2 to 6, further comprising a lip seal (14) held compressed by the sleeve (18, 28) before the translation of the sleeve applying the spreading force to the flexible flaps (15, 25), said translation moving the sleeve away from the lip seal, this lip seal being configured to seal the conduit (11) between the support tube (12) and the inner wall of the conduit after the sleeve is moved away from this lip seal.

8. Device (10, 20, 23) according to any one of claims 1 to 7, wherein the spreading means comprises a spring (24) mounted in tension or compression on the support tube, and held by a trigger (28), an external force to the device causing the trigger 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 a part of the spreading force on the flexible slats (15, 25).

9. Device (10, 20, 23) according to any one of claims 1 to 8, wherein the free end of each flexible slat (15, 25) has an anti-slip pad on its external surface.

10. Device (10, 20, 23) according to any one of claims 1 to 9, further comprising a breaking element configured to apply an external force to the device and then to break when the flexible strips (15, 25) are in the deployed configuration.

11. A stop device (30) comprising a positioning device (10, 20, 23) according to any one of claims 1 to 10, 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 device comprising: - the lip seal (14, 40) fixed hermetically to the outer wall of the support tube (12, 27, 39), such that, when the lip seal is in the deployed configuration, the only fluid passing through the stop device flows 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 providing 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 sides of the device, corresponding to this flow rate exceeding the predetermined value, thus retains the shutter in the second position.