Improved pipe assembly intended to be connected to a second pipe

Abstract

According to one aspect, the present invention relates to a pipe assembly (E) comprising a rotationally symmetric pipe (3) having a seal wall (36) comprising at least a first axial abutment portion (3440), a second axial abutment portion (3444) intended to abut a second pipe to be connected, and an inner surface (3460) formed by a recess (3060), the inner surface (3460) enabling elastic deformation of the seal wall (36) by compression having at least one axial component with respect to a seal deformation outer surface (3464) on the radially opposite side thereof. The assembly is mounted around the pipe (3) between a free position and an abutment position and further comprises an axially movable mounting member (32), the mounting member (32) comprising axial mounting means (324) for mounting to the second pipe and an axial abutment portion (321) which abuts the first axial abutment portion (3440) of the pipe (3) in the abutment position.

Description

Technical Field

[0001] The technical field of the present invention is the technical field of pipe joints.

[0002] The present invention relates to an assembly comprising a pipe and an axial fastening member for sealingly fastening the pipe to another pipe.

Background Art

[0003] Metal pipes for transporting fluid from one zone to a second zone are known. It is often necessary to join different pipes together. One problem is to ensure a seal between each pipe joint.

[0004] One solution is welded joints, but this type of joint is not possible for different applications for several reasons such as the risk of fire during welding or access behind the pipes. In this case, removable joints between two pipes are known. Since both pipes can be manufactured by different suppliers, joints are required that adapt to the manufacturing limitations of different manufacturers.

[0005] FIG. 1 shows a first pipe assembly 1 joined to a second pipe 2 according to an embodiment proposed by the applicant.

[0006] The pipe assembly 1 comprises a pipe 10 and a nut 12 having a tapping for screwing onto the thread of the second pipe 2. The first pipe 10 has an inner surface surrounding a volume within which fluid circulates to an open end. The inner surface is a regular cylindrical surface (same diameter) to reduce head loss.

[0007] The first pipe 10 comprises a joint 100 having a part of a cylindrical inner surface up to the open end and a conical outer surface. The second pipe has, at its open end, a conical inner surface corresponding to the conical outer surface of the first pipe, each forming a seal and a contact surface in contact.

[0008] The first tube 10 further comprises a contact portion 112 for the snap ring 121, and the snap ring 121 is inserted into the hole of the nut and contacts the contact portion 112.

[0009] When the nut 12 is screwed onto the second tube 2, the snap ring 121 contacts the contact portion 112 on the first tube 10, axially moves the seals and the contact surfaces of both tubes, and brings them closer together. When the nut is tightened on the second tube 2, the conical outer surface of the joint 100 is restricted by the conical inner surface of the second tube. However, at the seals and contact surfaces on both sides, there may be different dimensional limitations due to the dimensional tolerances of the tubes, snap rings and nuts related to manufacturing. Since this joint becomes invisible, a "trial joint", that is, a process of measuring and verifying the joint to ensure the invisible joint of both tubes is required. In practice, before attaching to the machine, first the operator tightens the nut on the second tube, measures the tightening torque, conducts a leak test between the two tubes, loosens the nut, separates the two tubes, and then, when the two tubes are joined to each other on the machine, the joint is made by applying the tightening torque corresponding to the executed tightening torque. Furthermore, this double process enables a trial joint to be made and confirms that neither of the two tubes has undergone any plastic deformation due to the tightening.

[0010] This double process performed by the operator is time-consuming and therefore costly. Furthermore, the tightening torque may change during multiple joining operations due to wear between the threads and tapping, or between both conical surfaces.

[0011] Therefore, a removable joint is required to ensure proper sealing between the two tubes that eliminates the need for the user to perform both operations without changing the second tube. SUMMARY OF THE INVENTION

[0012] The present invention provides a solution to the aforementioned problem by providing a removable joint for two tubes that ensures a seal level by means of metal / lubricant / metal contact and axial abutment between two tubes.

[0013] One aspect of the present invention relates to claim 1.

[0014] According to the present invention, the rotating seal wall has the function of a seal, and the radial surface that abuts against the first abutting portion makes it possible to determine the end point of movement. In fact, the operator can use a torque wrench and screw in the nut when both abutting portions (the second abutting portion with respect to the abutting portion of the corresponding second tube) come into contact.

[0015] The rotating seal wall is actually adapted to elastically deform the outer surface of the seal deformation when joining with the second tube by pressing the inclined surfaces of the second tubes to be joined and providing a seal therebetween. When the nut at the abutting position of the first tube is screwed into the second tube, both tubes are moved towards each other, whereby the inclined surface of the second tube presses against and slides on the outer surface of the seal deformation of the inclined portion (by friction reducible by a lubricant, for example a dry lubricant), and the inclined portion elastically deforms the rotating seal wall until the second surface forming the second axial abutting portion of the first tube abuts against the abutting portion of the second tube to be joined. In other words, the outer surface of the seal deformation is for abutting against and sliding on the inclined surface (between the radial direction and the axial direction, for example, inclined at X° with respect to the axis of the tube so that the angle is measured on the second tube side) of this seal wall of the second tube to be joined to elastically deform the rotating seal wall and thus provide a seal against the seal wall of the second tube.

[0016] When the fastening member is first fastened to the second tube, the seal wall mainly elastically deforms and may locally plastically deform, but during different removal and installation operations, the seal wall only undergoes elastic deformation.

[0017] In addition to the features discussed in the previous paragraph, a tube assembly according to one aspect of the present invention may have one or more complementary features from the following paragraphs, considered individually or in any technically possible combination.

[0018] According to one embodiment, the first tube comprises a main tube zone having a constant thickness between an inner surface and an outer surface, the connection zone extends from the main tube zone and has a joining end portion having an inner diameter or an outer diameter different from the diameter of the main tube zone, the connection zone includes the internal volume of the tube from the joining end portion to a first end forming a free edge surrounding the axial opening, the joining wall comprises an inner surface surrounding a first portion of the internal volume, and the sealing wall surrounds a second portion of the internal volume extending from the first portion of the internal volume to the axial opening.

[0019] According to an example of this embodiment, the inner surface of the joining wall includes different diameters, a part of the inner surface between two axial end portions has a diameter forming the minimum volume of the first portion of the internal volume, and the first axial abutment is axially positioned between the ends of a part of the inner surface.

[0020] According to another example, the inner surface of the joining wall includes a constant diameter and forms a first portion of a cylindrical internal volume.

[0021] According to one embodiment, the joining wall comprises an inner part having a first diameter and a limiting zone between the inner part and the sealing wall, and the limiting zone has the minimum diameter of the connection zone.

[0022] According to one embodiment, the joining wall comprises a groove extending from a first face of the collar to another abutment face, and the axial abutment of the fastening member is movable within the groove between the first axial abutment and the other abutment face defining the groove.

[0023] According to an example, the other abutment face defining the groove and the first face of the collar have a shape corresponding to the shape of the axial abutment of the fastening member. Thereby, deformation of the abutment of the fastening member is avoided. According to an exemplary embodiment, the end of the collar at the first face forming the first axial abutment is a fillet.

[0024] According to one embodiment, the collar has a groove that divides the collar into a first part and a second part. The first part has a first axial abutment portion that includes a thickness measured axially, and the thickness is lower than the thickness of the second part having a second axial abutment portion, and greater than the thickness of the seal wall measured between the inner surface and the outer surface of the seal deformation.

[0025] According to one embodiment, the axial abutment portion on the fastening member is a snap ring.

[0026] According to an example of this embodiment, the fastening member has a snap ring insertion port that penetrates the fastening member from the outer surface to the inner surface facing the pipe, and the insertion port has a portion corresponding to the snap ring on the inner surface surrounding the pipe.

[0027] According to one embodiment, the fastening member is a nut, and the fastening means is a tapping that is screwed into the thread of the second pipe.

[0028] According to an alternative form, the fastening member has a thread that is screwed into the nut of the second pipe.

[0029] According to one embodiment, the seal wall further has a cylindrical rotating portion that extends from the inclined portion to the second axial abutment portion of the collar. Thereby, the flexibility of the inclined portion can be increased and elastically deformed.

[0030] According to an alternative form of this embodiment, the seal wall has only an inclined portion that directly extends from the second axial abutment portion of the collar.

[0031] According to one embodiment, the portion of the inner surface that forms a part of the inclined portion of the seal wall is curved. Thereby, when contacting the second pipe, the elastic deformation of this inclined portion becomes easy.

[0032] According to one embodiment, the seal deformation outer surface is curved. This means that there is less friction due to contact with the second tube during elastic deformation of the inclined portion.

[0033] According to another embodiment, the inclined portion of the seal wall has the shape of a conical spring washer.

[0034] According to an example of this embodiment, the inclined portion of the seal wall has the shape of a conical spring washer. For example, the inner surface portion forming part of the inclined portion of the seal wall is also frustoconical.

[0035] According to one embodiment, the thickness of the seal wall between the inner surface and the seal deformation outer surface changes by less than 10%. For example, the inner surface portion forming part of the inclined portion of the seal wall is concentric with the seal deformation outer surface (and thus parallel in the case of a curved surface).

[0036] According to one embodiment, each element is a metal, such as steel, stainless steel, aluminum alloy or titanium alloy. For example, the tube is stainless steel type steel, and the fastening means includes an axial fastening means of stainless steel and a contact portion made of stainless steel.

[0037] According to one embodiment, the seal deformation outer surface is inclined with respect to the axis of the tube at an average angle of 1° or more and 45° or less. In the case of a curved outer seal deformation, the average angle is the average of the angles between the tangents of the cross-section of the surface and the axis X. In the case of a frustoconical seal outer surface, the average angle is the angle between the straight line of the cross-section of the seal surface and the axis X.

[0038] According to an example of this embodiment, the inner surface portion forming part of the inclined portion of the seal wall is inclined with respect to the axis of the tube at an average angle of 1° or more and 45° or less.

[0039] According to another embodiment, the seal deformation outer surface is inclined with respect to the axis of the tube at an average angle of 45° or more and 90° or less, and the counterbore forms a recess that defines the seal wall forming the inner surface.

[0040] According to an example of this another embodiment, the seal deformed outer surface extends from a second surface forming a second axial abutting portion of the color.

[0041] According to an example of this another embodiment, the portion of the inner surface forming a part of the inclined portion of the seal wall is inclined with respect to the axis of the tube at an average angle of 45° or more and 90° or less.

[0042] According to one embodiment, the collar is formed such that the second surface is at the axial end of the tube. In this example, the seal wall includes only an inclined portion extending directly from the second surface.

[0043] According to another embodiment, the seal wall further includes a cylindrical rotating portion extending from the inclined portion to the second surface of the collar.

[0044] According to one embodiment, the joining wall has an outer surface provided with a visual indicator corresponding to a zone that is at least partially covered by the fastening member in the free position and not at least partially covered in the abutting position when the fastening member is coupled to the second tube between a first surface forming a first axial abutting portion and an end of the joining wall on the axially opposite side of the seal wall. Thus, this indicator shows the operator whether the first tube is properly joined to the second tube.

[0045] According to an example of the mode with a visual indicator, the visual indicator is a marking indicating that the tightening is not complete.

[0046] According to an example, the visual indicator is completely visible only in the abutting position.

[0047] According to another example, the visual indicator is not partially covered from the free position.

[0048] According to an example, the fastening member has an axial end on the opposite side of the axial fastening means, and the fastening member has a notch at this axial end. Thereby, the operator can know when approaching the abutting position to be reached.

[0049] According to one example, the outer surface extends from the other abutment surface to the end of the joining wall.

[0050] According to one embodiment, the collar further comprises a groove that divides the collar into a first portion with a first abutment surface and a second seal and abutment wall, the second seal and abutment wall having a seal-deformed outer surface that extends from a second surface forming a second axial abutment portion, the groove enabling the second seal wall to be elastically deformed by compression having at least one axial component relative to the seal-deformed outer surface.

[0051] According to one example of this embodiment, the second collar seal wall defines the volume of the counterbore and has a radially inner surface that extends between a first radially outer end and a second radially outer end that joins the surface of the bottom of the counterbore, the first radially outer end being on the opposite side of the second radially outer end, and a radially outer surface that joins the first radially outer end of the seal-deformed outer surface and the first radially outer end of the radially inner surface, and further comprises an inner end that extends axially within the collar between the second radially outer end of the radially inner surface and the second radially outer end of the seal-deformed outer surface that joins the second surface forming the second axial abutment portion.

[0052] According to one example of this embodiment, the seal-deformed outer surface surrounds a portion of the rotating seal wall. According to one aspect of this example, the seal-deformed outer surface of the collar is inclined with respect to the second surface forming the second axial abutment portion. According to another aspect of this example, the seal wall includes an extra thickness for protruding the seal-deformed outer surface from the second surface forming the second axial abutment portion.

[0053] According to one example of this embodiment, the seal-deformed outer surface is adapted to be elastically deformed by the surface of the second tube that contacts this seal-deformed outer surface until the surface of the second tube contacts the second surface forming the second axial abutment portion.

[0054] The present invention also relates to a joining assembly, An assembly according to the foregoing aspect, having one or more of the different features of the preceding paragraph or not having them, and a second tube, wherein it has a sealing surface inclined with respect to the axis, which contacts and compresses the sealing deformation outer surface for elastically deforming the sealing wall, and an axial contact portion that axially contacts the second axial contact portion of the joining wall, and the axial fastening means is fastened to the complementary fastening means, the second tube comprising the axial contact portion, and relates to a joining assembly comprising a lubricant layer between the sealing deformation outer surface and the inclined sealing surface.

[0055] According to one embodiment of this joining assembly, the lubricant layer is a dry lubricant deposited on the sealing deformation outer surface.

[0056] According to one embodiment of this joining assembly, the inclined sealing surface of the second tube comprises a first free end and a second end extending from a radial surface that is on the opposite side of the free end and forms the axial contact portion of the joining wall, and the inclined sealing surface is frustoconical having a diameter at the first free end that is larger than the maximum diameter of the sealing deformation outer surface and a diameter at the second end that is lower than the maximum diameter of the sealing deformation outer surface.

[0057] According to one embodiment of this joining assembly, due to the elastic deformation of the sealing wall by the inclined sealing surface of the second tube, the sealing deformation outer surface of the first tube is forced against the inclined sealing surface of the second tube.

[0058] Another aspect of the present invention relates to a method of marking a tube assembly according to the aspect of the foregoing invention (claim 14).

[0059] According to one exemplary embodiment of this method, the step of creating a visual indicator on the tube is, for example, to create a laser marking on the entire circumference of the tube on an axially defined zone.

[0060] Another invention not claimed is a pipe assembly joined to a second pipe, the pipe assembly comprising a rotating pipe around an axis with a connection zone, a rotating joining wall with at least one collar, the collar comprising a first face forming a first axial abutment, a second face on the opposite side of the first face and forming a second axial abutment for abutting against the second pipe, and a rotating joining wall, an outer face with a visual indicator between the first face forming the first axial abutment and the end of the joining wall on the axially opposite side of the second axial abutment, a rotating seal wall extending from the joining wall and having a seal deformation outer face with a diameter that gradually and continuously increases from a first free end surrounding the opening of the pipe to a second end on the opposite side of the first end, and a rotating pipe, a fastening member mounted around the connection zone and axially movable between a free position where the visual indicator is at least partially covered by the fastening member and a contact position where the visual indicator is visible, axial fastening means fastened to complementary fastening means of the second pipe to be joined, and an axial abutment abutting against the first axial abutment of the pipe collar in the contact position, and a fastening member, characterized by a pipe assembly.

[0061] The present invention makes it possible to indicate to the user that the first pipe is in contact with the second pipe when joining both pipes via an attachment member covering both axial abutments. The visual indicator can be created by the method described above.

[0062] The present invention and its different applications will be better understood by reading the following description and examining the accompanying drawings.

[0063] The drawings are described for the purpose of illustrating the object of the present invention and are in no way limiting.

Brief Description of the Drawings

[0064]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8a

Figure 8b

Figure 8c

Figure 9a

Figure 9b

Figure 10

Figure 11

Figure 12

Figure 13a

Figure 13b

Figure 14a

Figure 14b

Figure 14c

Best Mode for Carrying Out the Invention

[0065] The drawings are described for the purpose of illustrating the present invention and are in no way limiting.

[0066] FIG. 2 is a schematic view of an axial cross-section of a pipe assembly E according to the first example of the first aspect of the present invention.

[0067] The pipe assembly E is to be joined to the second pipe 4 shown in the axial cross-section in the joining assembly R of FIG. 4. In other words, the joining assembly R includes the pipe assembly E and the pipe 4 joined to each other. FIG. 5 shows a joining assembly R including the pipe assembly E according to an alternative example of the first example of the first embodiment. FIG. 6 shows a joining assembly R different from FIG. 4.

[0068] Assembly E comprises a fastening member 32 and a rotary tube 3 around an axis X. The tube 3 comprises a connection zone 34 and a main tube zone. The tube 3 and / or the fastening member 32 are each made of a metal, such as steel, stainless steel, an aluminium alloy or a titanium alloy. For example, the tube 3 and the fastening member 32 are each made of stainless steel.

[0069] The main tube zone includes a regular thickness between an inner face and an outer face, where they are cylindrical here. The boundary between the connection zone 34 and the main tube zone is formed by a joining end of the connection zone 34 that extends from the main tube zone and has an inner diameter or an outer diameter different from that of the main tube zone. The connection zone 34 includes the internal volume of the tube 3 from the joining end to the opening 30, and the opening is formed by a first end 3461 that forms a free edge surrounding the axial opening 30.

[0070] Figure 3 is an enlarged view of Figure 2 in this connection zone 34. The fastening member 32 is attached and is axially movable between a free position and a contact position around the connection zone 34. Thus, the fastening member 32 is fastened to complementary fastening means 424 of a tube 4 and comprises axial fastening means 324 that enable the fastening member 32 and the fastening means 424 to be fastened to each other. In this example, the fastening member 32 is here a nut, its fastening means 324 is tapping, and the complementary fastening means 424 of the tube 4 is a screwed thread.

[0071] The connection zone 34 comprises a rotary joining wall 342 with at least one collar 344. The collar 344 comprises a first face forming a first axial contact portion 3440 and a second face forming a second axial contact portion 3444.

[0072] The tube 4 also comprises an axial contact portion 404 that contacts the second axial contact portion 3444 when in the contact position (and thus is potentially joined to the tube 3).

[0073] The fastening member 32 comprises an axial contact portion 321 that contacts the first axial contact portion 3440 of the collar 344 of the tube 3 when in the contact position.

[0074] Therefore, here, in order to perform fastening by screwing, the fastening member 32 moves along the rotation axis X toward the pipe 4 until the axial contact portion 321 abuts against the first axial contact portion 3440 of the collar 344. During fastening, here during screwing, the second pipe 4 approaches the first pipe until it contacts the second axial contact portion 3444 of the collar 344.

[0075] In this first embodiment, the second pipe 4 includes an axial contact portion 443 at the axial end of the complementary fastening means 424 of the pipe 4 here.

[0076] The joining wall 342 includes a groove 3421 extending from the first surface 3440 of the collar 344 to another contact surface 3422 (see FIG. 5 showing an alternative example for the first example shown in FIGS. 2 to 4). The axial contact portion 321 of the fastening member 32 is movable within the groove 3421 between the first axial contact portion 3440 and another contact surface 3422 defining the groove 3421. The assembly E shown in FIG. 5 is an alternative example of the assembly E of FIG. 4 in that another contact surface 3422 defining the groove 3421 is a radial surface. However, in the first example, as shown in FIGS. 2 and 4, another contact surface 3422 defining the groove 3421 has a shape corresponding to the shape of the axial contact portion 321 of the fastening member 32. In these two examples, the first surface (forming the contact portion) of the collar 344 has a shape corresponding to the shape of the axial contact portion 321.

[0077] In this embodiment, the axial contact portion 321 of the fastening member 32 is a snap ring. The fastening member 32 includes an insertion port 3210 as seen in the cross-sections of FIGS. 6, 10, and 11. FIGS. 10 and 11 show the appearances of the first example of the first embodiment in the free position and the contact position, respectively. The insertion port 3210 has a spiral shape, and its cross-section corresponds to the cross-section of the snap ring 321 and penetrates the fastening member 32 from the outer surface to the inner surface facing the tube 3. By surrounding the tube 3, the insertion port 3210 enables the snap ring to be inserted into the groove (by plastic deformation or elastic deformation). Therefore, in order to form the assembly E, the fastening member 32 without a snap ring forming the fastening member 32 is fitted into the connection zone 34 until the inner outlet of the insertion port 3210 faces the groove 3421, and then the snap ring is inserted into the insertion port 3210 (through its outer inlet) and deformed by deforming within the groove 3421 until the axial contact portion 321 is formed and exits from the inner outlet.

[0078] The tube 3 further includes a rotary seal wall 36 extending from the joining wall 342 to the opposite side of the first axial contact portion 3440.

[0079] The joining wall 342 includes an inner surface 3420 surrounding the first portion of the internal volume of the connection zone 34, and the seal wall 36 surrounds the second portion of the internal volume extending from the first portion of the internal volume to the axial opening 30.

[0080] The seal wall 36 includes an inclined portion 346 with respect to the rotation axis X of the tube 3, that is, its inner and outer surfaces are neither parallel nor perpendicular to the rotation axis X. The inclined portion 346 includes the first end portion 3461 of the tube 3.

[0081] The inclined portion 346 further includes a second end portion 3462 that is axially opposite to the first end portion 3461. In other words, the inclined portion 346 is axially defined between its two end portions 3462 and 3461. Beyond the second end portion 3462, the second end portion 3462 is also an end of the seal wall 36 (as in the second embodiment described below), or the seal wall 36 has a non-inclined portion, and in this first embodiment, the seal wall 36 includes a cylindrical rotating portion 360 that extends from the second end portion 3462 to the second axial contact portion 3444 of the collar 344 (having an inner surface and an outer surface parallel to the rotation axis X).

[0082] The inclined portion 346 further includes a seal deformation outer surface 3464 having a diameter that gradually and continuously increases from the first free end portion 3461 to the second end portion 3462.

[0083] The seal wall 36 includes an inner surface 3460 on the radially opposite side of the seal deformation outer surface 3464 formed by the counterbore 3060, thereby enabling the seal wall 36 to be elastically deformed by compression having at least one axial component with respect to the seal deformation outer surface 3464.

[0084] FIG. 7 shows a cross-section of a joining assembly R' including an assembly E according to a third example of this first embodiment, and reference is made to the difference in the inner diameter of the inner surface 3420 of the joining wall 342. A portion 34200 of the inner surface 3420 has a constant diameter D3420 that forms the minimum volume of the first portion of the internal volume. The portion 34200 is defined between the inner chamfer portion and the counterbore 3060. The first axial contact portion 3440 is axially disposed between the portion 34200 of the inner surface 3420, that is, between the inner chamfer portion and the counterbore 3060. Further, the example shown in FIG. 7 is different in that the fastening member 32 is axially short and does not include the markings described below.

[0085] In this first embodiment, at least before joining, the inner surface 3460 formed by the counterbore includes a diameter D3060 that is larger than the diameter D3461 of the inner surface 3460 at the opening 30 at the second axial abutting portion 3444 of the collar 344. The constant diameter D3420 of the portion 34200 is smaller than the diameters D3060 and D3461 of the counterbore.

[0086] The second tube 4 has an inclined sealing surface 406 (see FIG. 7) with respect to the axis X, and when the tube 4 is joined to the tube 3, the inclined sealing surface 406 contacts and presses against the sealing deformed outer surface 3464 by elastically deforming the sealing wall 36. In other words, at the time of joining, the sealing deformed outer surface 3464 first contacts the inclined sealing surface 406 of the tube 4, and at the time of fastening, by moving the tube 4 toward the tube 3 via the fastening member 32, the sealing wall 36 deforms until the axial abutting portion 404 axially abuts against the second axial abutting portion 3444 of the joining wall 342.

[0087] In the first example shown in FIG. 4 and the alternative example of FIG. 5, as well as the third example of FIG. 7, the inclined sealing surface 406 of the tube 4 is formed by a countersink and extends from an intermediate cylindrical inner surface formed by a counterbore. The intermediate cylindrical inner surface includes a diameter that is larger than the main inner surface extending from this intermediate cylindrical inner surface of the tube 4. In the second example of FIG. 6, the inclined sealing surface 406 of the tube 4 extends from the free end through the inner shoulder to the inner end adjacent to the main inner surface (the inner end has a diameter having a value between the diameter of the main inner surface and the diameter of the free end).

[0088] Furthermore, according to an example, the sealing deformed outer surface 3464 is curved by being convex or frustoconical, thereby enabling deformation by limiting friction when contacting the inclined sealing surface 406. According to one option, a part of the inner surface 3460 forming a part of the inclined portion 346 of the sealing wall 36 is curved by being concave or frustoconical as in the illustrated example. Therefore, the inclined portion of the sealing wall can have a shape like a conical snap ring.

[0089] The thickness of the seal wall 36 between the inner surface 3460 and the seal-deformed outer surface 3464 changes by less than 10%, and is preferably constant. In particular, the portion of the inner surface 3460 that forms part of the inclined portion 346 of the seal wall 36 is concentric with the seal-deformed outer surface 3464.

[0090] The inclined seal surface 406 of the second tube 4 includes a first free end 4061 and a second inner end 4062 on the axially opposite side of the first free end 4061. The first free end 4061 extends from a radial surface that forms the axial contact portion 404. The inclined seal surface 406 is frustoconical, having a diameter at the first free end 4061 that is larger than the maximum diameter of the seal-deformed outer surface 3464 and a diameter at the second end 4062 that is lower than the maximum diameter of the seal-deformed outer surface 3464.

[0091] In this first embodiment, the seal-deformed outer surface 3464 is inclined at an average angle of 1° or more and 45° or less, here for example 15°, with respect to the rotation axis X of the tube 3 before deformation. The portion of the inner surface 3460 that forms part of the inclined portion 346 of the seal wall 36 is inclined with respect to the rotation axis of the tube 3 at an average angle of 1° or more and 45° or less. Here, since this portion of the inner surface 3460 is concentric with the seal-deformed outer surface 3464, the angle is also 15°.

[0092] The seal-deformed outer surface 3464 enables seal contact with the inclined seal surface 406 of the tube by the forces exerted on each other by elastic deformation when the axial contact portion 404 axially contacts the second axial contact portion 3444 of the joining wall 342. The joining assembly includes a lubricant layer between the seal-deformed outer surface 3464 and the inclined seal surface 406 to reduce the friction between these two surfaces during fastening and thus during deformation.

[0093] In FIGS. 8a to 8c, it can be seen that as the axial contact portion 443 of the second tube 4 approaches the second axial contact portion 3444 of the tube 3, the stress of the seal wall 34 differs according to the deformation of the seal wall 34. In FIG. 8a, the seal deformation outer surface 3464 contacts the inclined seal surface 406. In FIG. 8b, the tube 3 approaches the tube 4 at an intermediate position by deforming the seal wall 34 (by a fastening member 32 not shown screwed into the thread of the tube 4). In FIG. 8c, it can be seen that the tube 3 is joined to the second tube 4 with the axial contact portion 443 of the second tube 4 in contact with the second axial contact portion 3444 of the tube 3. At this position, the seal between the seal deformation outer surface 3464 and the inclined seal surface 406 becomes possible due to the visible stress exerted by the elastic deformation of the seal wall 34.

[0094] According to the second embodiment, the assembly E and the assembly R are different from the first embodiment in that the seal wall 36' of the tube 3 and the inclined seal surface 406' of the second tube 4' are different.

[0095] FIGS. 9a and 9b show partial cross-sections of the tube 3 and the second tube 4 of the assembly R at the seal wall 36' and the inclined seal surface 406' in the non-joined position and the joined position, respectively.

[0096] In this second embodiment, the seal wall 36' includes only the inclined portion 346' that directly extends as an extension of the second axial abutting portion 3444' of the collar 344'. The seal deformed outer surface 3464' is inclined at an average angle of 45° or more and 90° or less with respect to the rotation axis X of the tube 3'. Here, the inclined portion 346' includes only the seal deformed outer surface 3464' that extends as an extension of the second surface forming the second axial abutting portion 3444'. The counterbore in this second embodiment forms a recess 3060' that defines the seal wall 346' forming the inner surface 3460'. The portion forming a part of the seal wall 36' is inclined with respect to the rotation axis X of the tube 3' and has an average angle of 45° or more and 90° or less. Preferably, as in the first embodiment, this portion of the inner surface 3460 forming a part of the seal wall 36 is parallel to the seal deformed outer surface 3464'. In this case, each is curved (concave in the seal deformed outer surface 3464' and convex in this portion of the inner surface 3460). Therefore, the collar 344 of the rotary joint wall 342' is formed by the groove 3421 (forming the first axial abutting portion) and the curved portion of the seal deformed outer surface 3464'. The advantage of this second embodiment is that the connection zone is more compact in the axial direction.

[0097] The inclined seal surface 406' of the second tube 4' extends to the first free inner end 4060' as an extension of the axial abutting portion 404'. The inclined seal surface 406 and the axial abutting portion 404' are frustoconical surfaces having an outer diameter at the outer end of the axial abutting portion 404' that is larger than the maximum diameter of the seal deformed outer surface 3464' and an inner diameter at the first free inner end 4060' that is at least lower than the maximum diameter of the seal deformed outer surface 3464'. Here, the inner diameter is smaller than the minimum diameter of the seal deformed outer surface 3464'.

[0098] The seal wall 36' having the second axial abutting portion 3444' is disposed with respect to the inclined seal surface 406 and the axial abutting portion 404', and the inner end of the seal wall 36' first contacts the inclined seal surface 406 to elastically deform the seal wall 36'. Then, as seen in FIG. 9b, at the abutting position, the seal wall 36' is elastically deformed by the inclined seal surface 406' of the second tube 4', resulting in stress on the seal deformation outer surface 3464' of the first tube 3 and the inclined seal surface 406' of the second tube providing the seal. It can be seen that the deformation of the seal wall 36' generates a deformation closer to the frustum surface of the inclined seal surface 406 than the curvature in the initial state (the state without elastic deformation before contacting the tube 4') with respect to the seal deformation outer surface 3464'.

[0099] Optionally, the tube assembly E is marked by a visual indicator according to one aspect of another invention. FIGS. 10 and 11 show the marking of the joining assembly R according to the first example of the first embodiment, but it can also be applied to its alternatives and second examples as well as the second embodiment. The marking can also be applied with modifications to the example shown in FIG. 1.

[0100] The joining wall 342 includes an outer surface with a visual indicator 307 corresponding to a zone that is at least partially covered by the fastening member 32 in the free position and not at least partially covered in the abutting position, between the first surface forming the first axial abutting portion 3440 and the end of the joining wall 342 on the axially opposite side of the seal wall 36, when the fastening member is coupled to the second tube 4.

[0101] In this example, as can be seen in FIG. 11, the visual indicator 307 is only fully exposed at the abutment position. In this example, as can be seen in FIG. 10, the visual indicator 307 is not partially covered at the free position 307. In this example, the fastening member 32 includes a notch 327 located at an axial end opposite the axial fastening means 324. These notches allow the visual indicator 307 to be partially covered, thus warning the user whether the fastening member 32 is fully screwed into the second tube 4 and the axial abutment portion 404 of the second tube 4 is axially abutted against the second axial abutment portion 3444 of the joint wall 342 of the first tube 3.

[0102] Here, the marking method will be described in relation to FIG. 12 showing different axial dimension chains on the axial cross-section of the first example of the tube assembly E according to the first embodiment at the abutment position where the marking operates.

[0103] The abutment portion 321 includes an axial length l321, the collar 344 includes an axial length l344, and the fastening member 32 includes an overall axial length l32. The assembly E includes an axial length L324 between the end of the fastening member 32 and the second axial abutment portion 3444 of the joint wall 342.

[0104] The marking method includes the step of inserting a second test tube against the second axial abutment portion 3444 of the first tube 3 forming the joint marking assembly. The second test tube is provided with axial fastening means corresponding to the axial fastening means of the fastening member 32 and is arranged so as not to elastically deform the seal wall 36. In other words, the second test tube does not include an inclined seal surface 406, but includes an inner diameter larger than the maximum outer diameter of the seal wall 36 and an inner cylindrical wall having an axial length larger than the axial length of the seal wall 36, thus enabling the axial end of the second test tube to abut against the second axial abutment portion 3444. This axial end is preferably a radial surface.

[0105] Next, the method includes positioning the fastening member 32 at the abutting position by a step of tightening the fastening member 32 to a predetermined torque in the second test tube.

[0106] Next, the method includes, here following the notch 327, a step of creating a visual indicator 307 on the tube 3. This step can be performed by a laser, for example, by marking the entire circumference of the tube on an axially defined zone. Here, the visual indicator is created on the entire circumference of the tube on an axially defined zone indicating that the tightening is not complete. Thus, regardless of the chain of dimensions of the lengths L324, L344, L321 and L32, the marking is formed to indicate to the user the screwing distance of the fastening member to ensure that there is a minimum pressure between the second axial abutting portion 3444 and the axial abutting portion 443 of the first tube 3. Thus, during the manufacture of the assembly E, each of these chains of dimensions has its own manufacturing tolerances, creating differences between the various objects. The visual indicator indicates to the user that when the second tube is connected to the assembly E, the axial abutting portion 443 of the tube 4 is in contact with the second axial abutting portion 3444 of the tube 3.

[0107] FIG. 13a shows an axial cross-section of an example of a part of a joining assembly R comprising a tube assembly E according to the third embodiment in the abutting position. This tube assembly E differs from the first example of the first embodiment in that the collar 344' has a groove 3442. The second tube 4 is the same as in the first example of the first embodiment.

[0108] Thus, the collar 344’ includes a first portion 3441 having a first axial abutting portion 3440 that abuts here against the axial abutting portion 321 of the fastening member 32, and here against the snap ring. The collar 344’ includes a second portion 3443 on the opposite side, separated by a groove 3442, having a second axial abutting portion 3444 that abuts here against the axial abutting portion 404 of the second tube 4. The thickness of the second portion 3443 measured axially is preferably greater than the thickness of the first portion 3441. The thickness of the first portion measured axially is even greater than the thickness of the seal wall 36 measured between the inner surface 3460 and the seal deformation outer surface 3464 perpendicular thereto. Thus, this enables the seal wall 36 to elastically deform before the snap ring or the first portion 3441 deforms.

[0109] The groove 3442 enables the first portion 3441 to elastically deform to avoid the snap ring from being crushed and plastically deformed during tightening.

[0110] Thus, this third embodiment includes a visual indicator made in the same way as the marking method described above, and in the step of positioning the fastening member 32 in the abutting position by the step of tightening the fastening member 32 to a predetermined torque on the second test tube, the visual indicator is adapted to further elastically deform this first portion 3441 in order to ensure a proper seal between the first tube 3 and the second tube 4.

[0111] Figure 14a shows an axial cross-section of an example of a part of a joining assembly R comprising a tube assembly E according to the fourth embodiment at the abutting position. This tube assembly E differs from the example of the third embodiment in that the second part is a second seal and an abutting wall 3443' having a seal deformation outer surface 3446 extending from a second surface 3444 forming a second axial abutting part. The groove 3442' is, in this embodiment, close enough to the seal deformation outer surface 3446 that the second seal and the abutting wall 3443' elastically deform when contacting the tube 4. Figure 14b schematically shows an enlarged view of the zone surrounded by the tube 4 with respect to the tube 3, as well as the stresses (schematic) in this second seal and the abutting wall 3443 and the rotating seal wall 36. Therefore, the thickness of the second seal and the abutting wall 3443' measured axially is preferably lower than the thickness of the first part 3441' (different from the third embodiment). The depth of the groove 3442' is such that the end of the second axial abutting part 3444 closest to the axis is closer to this axis than the bottom of the groove 3442'. In other words, the radius of the bottom of the groove is larger than the minimum radius of the second axial abutting part 3444 (at the fillet with the wall 36).

[0112] The second tube 4 is the same as the first example of the first embodiment.

[0113] Therefore, the collar 344' comprises a first part 3441 having a first axial abutting part 3440 that abuts here against the axial abutting part 321 of the fastening member 32 and here against a snap ring. The first part 3441 has, on the opposite side of the first axial abutting part 3440, a second surface 3447 seen in Figure 14b. The collar 344' has, on the opposite side that abuts against the axial abutting part 443 (also called 404, 404' in other examples) of the second tube 4 and separated by the groove 3442, a second seal and an abutting wall 3443' having a seal deformation outer surface 3446 extending from a second axial abutting part 3444' as seen in Figures 4c and 4a and 4b.

[0114] The thickness measured axially of the second seal and the abutment wall 3443’ is closer to the thickness of the seal wall 36 measured between the inner surface 3460 and the seal deformation outer surface 3464, when the measurement is made perpendicular to these two surfaces. The thickness measured axially of the first portion 3441’ is even greater than the thickness of the seal wall 36 measured radially between the inner surface 3460 and the seal deformation outer surface 3464 perpendicular thereto. Thus, this enables the seal wall 36 and the second seal and the abutment wall 3443’ to be elastically deformed prior to the deformation of the snap ring or the first portion 3441.

[0115] Thus, this example of the fourth embodiment comprises a visual indicator produced in the same manner as the marking method described above, and in the step of positioning the fastening member 32 in the abutting position by the step of tightening the fastening member 32 to a predetermined torque in the second test tube, the visual indicator is adapted to further elastically deform this first portion 3441 in order to ensure a proper seal between the first tube 3 and the second tube 4.

[0116] According to an example of the present embodiment, the second seal wall 3443’ of the collar 344’ further comprises a radially inner surface 3445 that defines the volume of the groove 3442’ by axially defining the groove 3442’ together with the surface 3447 of the first portion 3441’. This inner radial surface 3445 extends between a first radial end and a second radial end that joins the surface of the bottom 3448 of the groove 3442’. The first radial end is on the opposite side of the second radial end. The second seal wall 3443’ of the collar 344’ comprises a radial outer surface 3449 that joins the first radial end of the seal deformation outer surface 3446 and the first radial end of the radially inner surface 3445.

[0117] The second seal wall 3443’ of the collar 344’ is defined radially by an inner end shown by the dotted line in Fig. 14c that extends axially between the second radial end of the radially inner surface 3445 and the second radial end of the seal deformation outer surface 3446 that joins the second surface forming the second axial abutment 3444’.

[0118] According to this example of the present embodiment, the seal deformed outer surface 3446 includes an additional thickness as seen in FIG. 14C that (very slightly as indicated by the dotted line) surrounds a part of the rotating seal wall 346.

[0119] Unless otherwise specified, the same elements that appear in different figures have a single reference numeral.

Claims

1. A pipe assembly (E) joined to a second pipe (4, 4'), the pipe assembly (E) comprising a rotating pipe (3, 3') around an axis (X) having a connection zone (34), a rotating joint wall (342, 342') having at least one collar (344, 344'), the collar comprising 1. a first face forming a first axial abutment (3440, 3440'); and 2. a second face forming a second axial abutment (3444, 3444') for abutting against the second pipe (4, 4'); a rotating joint wall a rotating seal wall (36, 36') extending from the joint wall (342, 342'), the rotating seal wall (36, 36') comprising 1. an inclined portion (346, 346'), comprising a. a first end (3461, 3461') forming a free edge surrounding the axial opening (30) of the pipe (3, 3'); b. a second end (3462, 3462') axially opposite to the first end (3461, 3461'); and c. a seal deformation outer surface (3464, 3464') having a diameter that increases progressively and continuously from the first free end (3461, 3461') to the second end (3462, 3462'); an inclined portion (346, 346') 2. an inner surface (3460, 3460') on the radially opposite side of the seal deformation outer surface (3464, 3464'), formed by a counterbore (3060, 3060') for elastically deforming the seal wall (36) by compression having at least one axial component with respect to the seal deformation outer surface (3464, 3464'); a rotating seal wall (36, 36'); a rotating pipe (3, 3') a fastening member (32) attached around the connection zone (34) and axially movable between a free position and an abutment position, the fastening member (32) comprising axial fastening means (324) fastened to complementary fastening means (424) of the second pipe (4) to be joined; and an axial abutment (321) abutting against the first axial abutment (3440) of the collar (344) of the pipe (3) in the abutment position A pipe assembly (E) joined to a second pipe (4, 4'), characterized by comprising the above.

2. The joining wall (342, 342') comprises a groove (3421, 3421') extending from the first face (3440, 3440') of the collar (344, 344') to the other abutment face (3422), and the axial abutment portion (321) of the fastening member (32) is movable within the groove (3421, 3421') between the first axial abutment portion (3440, 3440') and the other abutment face (3422) defining the groove (3421), a pipe assembly (E) joined to the second pipe (4, 4') according to claim 1.

3. The collar (344) comprises a groove (3442) dividing the collar into a first part and a second part, the first part comprising a first axial abutment portion (3440) including a thickness measured axially, the thickness being lower than the thickness of the second part (3443) comprising the second axial abutment portion (3444), greater than the thickness of the seal wall (36) measured between the inner face (3460) and the seal-deformed outer face (3464), a pipe assembly (E) joined to the second pipe (4, 4') according to claim 1 or 2.

4. The seal wall (36) further comprises a cylindrical rotating portion (360) extending from the inclined portion (346) to the second axial abutment portion (3444) of the collar (344), a pipe assembly (E) joined to the second pipe (4) according to any one of claims 1 to 3.

5. The joining wall (342, 342') has an outer surface provided with a visual indicator (307) corresponding to a zone that is at least partially covered by the fastening member in the free position and not at least partially covered in the abutment position when the fastening member (32) is coupled to the second pipe (4, 4'), a pipe assembly (E) joined to the second pipe (4, 4') according to any one of claims 1 to 4.

6. The visual indicator (307) is completely visible only in the abutment position, a pipe assembly (E) joined to the second pipe (4, 4') according to claim 5.

7. The fastening member (32) comprises an axial end opposite the axial fastening means (324), and the fastening member (32) comprises a notch (327) at this axial end, a pipe assembly (E) joined to the second pipe (4, 4') according to claim 5 or 6.

8. The fastening member (32) is a nut, and the fastening means (324) is a tapping that is screwed into the thread of the second tube (4). The tube assembly (E) joined to the second tube (4, 4') according to any one of claims 1 to 7.

9. The tube assembly (E) joined to the second tube (4, 4') according to any one of claims 1 to 8, wherein the seal deformation outer surface (3464, 3464') is curved.

10. The tube assembly (E) joined to the second tube (4') according to any one of claims 1 to 9, wherein a part of the inner surface (3460) forming a part of the inclined portion (346') of the seal wall (36) is curved.

11. The tube assembly (E) joined to the second tube (4) according to any one of claims 1 to 10, wherein the seal deformation outer surface (3464) is inclined with respect to the axis (x) of the tube (3) at an average angle of 1° or more and 45° or less.

12. The tube assembly (E) joined to the second tube (4') according to any one of claims 1 to 10, wherein the seal deformation outer surface (3464') is inclined with respect to the axis (x) of the tube (3') at an average angle of 45° or more and 90° or less, and the counterbore forms a recess (3060') that defines the seal wall (346') forming the inner surface (3460').

13. A joining assembly (R), the assembly (E) according to any one of claims 1 to 12, a second tube (4, 4'), a seal surface (406, 406') inclined with respect to the axis (X) that contacts and compresses the seal deformation outer surface (3464, 3464') that elastically deforms the seal wall (36, 36'), axial abutting portions (404, 404', 443) that axially abut against the second axial abutting portions (3444, 3444') of the joining wall (342, 342'), and the axial fastening means (324) is fastened to the complementary fastening means (424). The second tube (4, 4') comprising the axial abutting portions (404, 404', 443), and a lubricant layer between the seal deformation outer surface and the inclined seal surface. The joining assembly (R).

14. A method for marking the tube assembly (E) according to any one of claims 1 to 12, A step of inserting a second test tube with respect to a second axial contact portion (3444, 3444') forming a joining marking assembly, wherein the second test tube is provided with axial fastening means corresponding to the axial fastening means of the fastening member (32), and the second test tube is arranged so as not to elastically deform the seal walls (36, 36'), A step of positioning the fastening member (32) at the contact position by a step of tightening the fastening member (32) to a predetermined torque with respect to the second test tube, A method including a step of creating a visual indicator (307) on the tubes (3, 3').

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