FR2676523A1 - Device for leaktight coupling of two coaxial assemblies and application of this device to the leaktight coupling of a valve body and a sealing cup (seal-containing pot) and to the sealed coupling of two pipes - Google Patents

Abstract

The present invention relates to a device for the sealed coupling of two coaxial assemblies, as well as to the application of this device to the sealed coupling of a valve body and a sealing cup and to the sealed coupling of two pipes. In order to couple, in sealed fashion, a male assembly (3) and a female assembly (1, 22, 26) exhibiting annular shoulders (36, 33) placed face to face and which clamping means (40), acting on the two assemblies (3, 1, 22, 26) tend to bring together, means (frustoconical faces 32 and 37) are provided for clean mechanical abutment between the two assemblies (3, 1, 22, 26) for imposing upon the said mutual bringing-together a limit such that the shoulders (36, 33) apply, to an elastically compressible annular seal (44) interposed between them, a determined prestress applying them against sealing surfaces (37, 11) of the two assemblies (3, 1, 22, 26). The seal (44) thus plays no role in the mechanical coupling of the two assemblies (3, 1, 22, 26) and its prestress results solely from the search for sealing.

Description

The present invention relates to a sealed connection device for two sealed assemblies having the same determined longitudinal axis,
- a male assembly having a transverse annular shoulder which is turned in a determined longitudinal direction and is connected, in a centripetal radial direction, to an annular, longitudinal sealing surface turned in a centrifugal radial direction,
- a female assembly having a transverse annular shoulder which is turned in the opposite direction to said determined longitudinal direction, faces the transverse shoulder of the male assembly, and is connected, in a centrifugal radial direction, to an annular bearing, longitudinal sealing turned in a centripetal radial direction and facing the longitudinal sealing surface of the male assembly,
said device comprising an elastically compressible annular seal interposed between the transverse shoulders and longitudinal sealing surfaces of the two assemblies and clamping means for applying to the two assemblies a longitudinal bias for mutual approach of the transverse shoulders so as to put the annular seal in prestress between them and pressing it radially against the longitudinal sealing surfaces.

 Such devices are for example used to ensure the sealed connection of a valve body, constituting the female assembly, and of a seal packing receptacle receiving a valve control shaft and constituting the male assembly, or still the sealed connection of two pipes, one of which is tightly secured to the male assembly while the other is securely secured to the female assembly, these examples being in no way limiting.

 In their currently known embodiments, these sealed connection devices are characterized in that the annular seal constitutes the only obstacle opposing that, under the action of the clamping means, the two assemblies move one by relationship to each other until contact is made between their transverse shoulders.

 Therefore, it must play not only a sealing role between the two assemblies, but also a role of longitudinal stop between the latter, the mutual joining of which requires the application to the joint of a considerable prestress of longitudinal compression between the respective transverse shoulders of the two sets. This prestressing can cause plastic deformation of the seal and, in particular, a radial application of the latter on the respective longitudinal sealing surfaces of the two assemblies under conditions such that the seal is in fact permanently secured to one and the other of the sub-assemblies, and thus makes the connection obtained impossible to dismantle without destruction. Naturally, moreover, it is necessary to size the male and female assemblies, in particular radially, in such a way that they resist the forces which are their thus applied by the annular seal.

 This drawback is encountered both in the case of leaktight connection devices between two pipes and in the case of connection devices between a valve body and a packing vessel.

 In addition, in the latter case, the annular seal undergoes not only the longitudinal prestress resulting from the action of the clamping means but also a longitudinal stress resulting from the overpressure existing inside the valve body, constituting the female assembly. , in comparison with the outside of the latter, which applies over the entire cross section of the seal cup, constituting the male assembly, and tends to drive the latter out of the valve body; only the longitudinal support of the transverse shoulder of the seal packing vessel on the transverse shoulder of the valve body, via the annular seal, is opposed to this tendency which is consequently reflected by the application , at the annular seal, a significant increase in longitudinal stress between the respective transverse shoulders of the packing pot and the valve body. The aforementioned effect of plastic deformation of the seal can be accentuated and, if said overpressure prevails only intermittently inside the valve body, that is to say under conditions such that the seal must undergo Geometric variations to permanently ensure the required seal, can cause rapid loss of this seal.

 The object of the present invention is to remedy these drawbacks and, to this end, the present invention provides a sealed connection device of the type indicated in the preamble, further characterized in that it comprises means of frank mechanical stop between the two assemblies to impose on said mutual approximation a limit such that the transverse shoulders of the two assemblies are mutually spaced longitudinally, after tightening, by a determined longitudinal distance, corresponding to a determined longitudinal prestress of the annular seal.

 Naturally, the devices generally have a general symmetry of revolution around the aforementioned axis, it being understood that other configurations could possibly be provided, depending on specific needs, without departing from the scope of the present invention. .

 It is easily understood that it results from the presence of the frank mechanical stop means between the two assemblies a dissociation of the functions hitherto assumed by the annular seal, namely the sealing function which it retains and the function of limitation of the relative longitudinal displacement of the two assemblies during tightening, which is now filled by said frank mechanical abutment means. As a result, the only longitudinal compression which is still applied to the joint results on the one hand from the predetermined prestressing which is imposed on it on tightening and on the other hand of the difference between the fluid pressures to which the respective transverse shoulders of the male assembly and of the female assembly are exposed, and this longitudinal compression can be maintained at lower values than previously, and in particular to values preserving the elasticity of the joint, insofar as the joint is relieved of all role in the mechanical connection of the two assemblies.

As a result, the seal, which is less compressed longitudinally, in comparison with the seals of the prior art, is applied less strongly on the respective longitudinal sealing surfaces of the two assemblies while providing the required seal, which authorizes disassembly without destruction and reassembly. In the specific case of an application to a valve, the body of which constitutes the female assembly and the seal pad the male assembly, only the cross section of the seal facing the transverse shoulder of the packing vessel is subjected to the pressure of the fluid present in the valve, instead of the seal being subjected to the effect of the application of this pressure on the entire cross section of the packing vessel tightness, so that the joint undergoes thereby a much less increase in longitudinal compression and retains an elasticity capable of ensuring a permanent seal whatever variations this compression may experience as a function of variations in pressure of the fluid present inside the valve body.

 Insofar as a lesser longitudinal compression of the annular seal entails the application of lower radial forces, by the latter, to the respective longitudinal sealing surfaces of the two assemblies, it is possible to reduce the mechanical resistance of the latter, that is to say to reduce the amount of material necessary for their manufacture, which lightens them and reduces their cost.

 Naturally, the material constituting the annular seal can be chosen from a wide range of possibilities, depending on the specific working conditions of this seal; thus, when the latter is intended to withstand particularly high or particularly low temperatures, or even pronounced temperature differences, and / or significant differences between the fluid pressures to which the transverse shoulder of l are exposed respectively. 'male element and the transverse shoulder of the female element, and / or to significant mechanical forces applied to the two assemblies and / or to particularly corrosive fluids, it is advantageous to choose as an annular seal a graphite seal, it being understood that other materials known in the field of the production of seals can be chosen without departing from the scope of the present invention, for example polytetrafluoroethylene.

 In a manner known per se, in the case where the respective transverse shoulders of the male assembly and of the female assembly are exposed to different fluid pressures, the device according to the invention can advantageously include an annular seal press , substantially incompressible longitudinally, between the annular seal and the transverse shoulder which is subjected to the highest fluid pressure; this seal press creates a piston effect between the fluid in which this pressure prevails and the seal.

In most applications, and in particular in the aforementioned applications, to the sealed connection of a valve body, constituting the female assembly, and of a seal packing housing receiving a valve control shaft and constituting the assembly male, or to the sealed connection of two pipes, one of which is secured to the male assembly and the other of which is secured to the female assembly, it is convenient to locate the recessed abutment means centripetal with respect to the longitudinal sealing surface of the male assembly and to the transverse shoulder of the female assembly. In addition, in the case of certain applications and in particular in the case of an application to the sealed connection of a valve body, constituting the female assembly, and a seal packing pot, constituting the male assembly, provision may be made for the longitudinal sealing surface of the female assembly to be parallel to the axis, that the longitudinal sealing surface of the male assembly is oblique to the axis, which it approaches in said determined longitudinal direction, and that the abutment means comprise
on the one hand, a direct annular extension of the longitudinal sealing surface of the male assembly,
- On the other hand, an annular surface complementary to said extension, arranged on the female assembly and placed back in said longitudinal direction determined with respect to the transverse shoulder of the female assembly.

 By "direct annular extension" means an extension retaining the same obliquity as the longitudinal sealing surface of the male assembly, relative to the axis, and not forming a recess relative to this scope; in the most general case, where the longitudinal sealing surface of the male assembly is conical of revolution around the axis, its direct annular extension is placed on the same geometric cone.

As a variant, in the case of other applications and in particular in the case of an application to the sealed connection of two pipes, and while providing that the abutment means are located in centripetal withdrawal relative to the longitudinal sealing surface of the male assembly and the transverse shoulder of the female assembly, it is also possible to provide that the longitudinal sealing surfaces of the two assemblies are parallel to the axis and that the abutment means comprise
on the one hand, a direct annular extension of the transverse shoulder of the female assembly,
- On the other hand, an annular surface complementary to said extension, arranged on the male assembly and to which the longitudinal sealing surface of the male assembly is connected in said determined longitudinal direction.

 In this case, the expression "direct annular extension" of the transverse shoulder of the female assembly is understood to mean, in the general case where this shoulder is plane and perpendicular to the axis, a coplanar extension of this shoulder.

 The transverse shoulder of the female assembly, its direct annular extension and the longitudinal sealing surface of the female assembly may consist of a single piece, but it may be better to produce them in the form of respective parts, assembled with seal.

Thus, for example in the case of an application to the sealed connection of two pipes and when the longitudinal sealing surfaces of the two assemblies are parallel to the axis while the abutment means comprise the aforesaid direct annular extension of the shoulder transverse of the female assembly, towards the axis, and the abovementioned annular surface complementary to said extension, arranged on the male assembly, in centripetal withdrawal relative to the longitudinal sealing surface of the latter, it can advantageously be provided that the female set includes
a longitudinal annular envelope constituting the longitudinal sealing surface of the female assembly, which extends beyond the transverse shoulder of the female assembly in opposite direction to said determined longitudinal direction,
an added transverse ring constituting the transverse shoulder of the female assembly and said extension and furthermore having a transverse face turned in said determined longitudinal direction, opposite to the transverse shoulder of the female assembly and of said extension, and a longitudinal outer peripheral face to which the transverse shoulder of the female assembly and said transverse face of the ring are connected in a centrifugal radial direction and which is placed in free contact with the longitudinal sealing surface of the assembly female,
- a male part located longitudinally opposite the male assembly relative to the ring and secured to the casing, said male part comprising
a transverse annular shoulder which is turned in the opposite direction to said determined longitudinal direction, faces the transverse face of the ring and is connected, in a centrifugal radial direction, to the longitudinal sealing surface of the female assembly,
* a transverse annular surface which is turned in the direction opposite to said determined longitudinal direction and offset on the one hand longitudinally by a determined longitudinal distance, in said opposite direction, and on the other hand in centripetal radial direction relative to the transverse shoulder of the male part and faces the transverse face of the ring against which it is in longitudinal abutment after tightening,
* an annular, longitudinal sealing surface which is rotated in a centrifugal radial direction, faces the longitudinal sealing surface of the female assembly and mutually connects the transverse surface of the male part and the transverse shoulder of the part male,
- And another elastically compressible annular seal interposed in determined longitudinal preload, after tightening, between the transverse shoulder of the male part, the transverse face of the ring and the longitudinal sealing surfaces of the female assembly and the part male.

 A person skilled in the art will readily understand that the sealed connection between the male part of the female assembly and the envelope thereof is carried out under the same conditions, via the other annular seal, as the sealed connection. between the male and female assemblies respectively, with the same advantages, the added transverse ring constituting a spacer limiting the longitudinal approximation of the male part and the male assembly and delimiting with each of them, and with the envelope, a space of perfectly determined longitudinal dimension for each joint, which causes for each of them a determined prestress.

 Naturally, in this case and when the transverse face of the ring and the transverse shoulder of the male part are exposed to different fluid pressures, the device preferably comprises an annular joint press, substantially incompressible longitudinally, between the another annular seal and the transverse face of the ring or the transverse shoulder of the male part, respectively, which is subjected to the highest fluid pressure. This seal press acts as a piston between the fluid with the highest pressure and the other annular seal.

 Other characteristics and advantages of a device according to the invention will emerge from the description below, relating to three nonlimiting examples of implementation, corresponding to the two aforementioned applications, as well as from the appended drawings which form an integral part of this description.

 - Figure I shows a device according to the invention applied to the sealed connection of a valve body and a seal packing receptacle receiving a valve control shaft, partly in section through a plane including the axis of this shaft, which constitutes the longitudinal axis of the device.

 - Figure 2 shows a device according to the invention applied to the sealed connection of two pipes, half in elevation and half in section by a plane including the common axis of the latter, which constitutes the longitudinal axis of the device.

 - Figure 3 shows, in a view similar to that of Figure 2, a simplified variant of the device according to the invention applied to the sealed connection of two pipes.

 We will first refer to Figure 1, where we have designated by 1 a tight, rigid valve body of which only a part in the form of a tubular sleeve, of revolution about an axis has been shown. longitudinal 2 which will serve as a reference to the notions of longitudinality, transversality, as well as centrifugal or centripetal radial character; the illustrated part of the valve body 1 receives in an integral but removable manner, with sealing, a sealed container 3 with seals 4, itself having a general shape of revolution around the axis 2 and ensuring the sealed passage, between the inside 5 of the valve body and the outside 6, with rotation guidance about the axis 2, of a coaxial shaft 7 for controlling a shutter, not shown, placed inside 5 valve body 1 and evolving, during a translation of the shaft 7 along the axis 2 relative to the valve body 1, between an open position of the valve and a closed position of the latter.

 For this purpose, the pot 3 is pierced right through, along the axis 2, with a longitudinal bore 8 inside which the seals 4 are arranged maintained, by gland means 9 applying them a longitudinal compression, in sealing abutment against an outer peripheral face 10, cylindrical of revolution around the axis 2, that the control shaft 7 presents in the direction of a distance with respect to this axis 2. This mounting of the control shaft 7 inside the pot 3 is well known to a person skilled in the art and, moreover, it is indifferent with regard to the present invention so that it will not be described further.

To receive the pot 3, the valve body 1 has meanwhile, in its sleeve-shaped part, an inner peripheral face
It is cylindrical in revolution around the axis 2 towards which it is turned: with a diameter greater than that of the outer peripheral face 10 of the control shaft 7. This inner peripheral face 11 extends from the inside 5 of the valve body 1 to the outside 6 thereof, where it is connected to a flat transverse face 12 turned in a longitudinal direction 13 going from the inside 5 towards the outside 6 of the valve body 1; the face 12 is thus perpendicular to the axis 2. At its connection with the face 12, which defines for the illustrated part of the valve body 1 an end face, the inner peripheral face 11 has an annular recess 14 of revolution around of axis 2 and delimited by a cylindrical bottom face 15 of revolution around axis 2 towards which it is turned, with a diameter slightly greater than that of the inner peripheral face
11, which bottom face 15 is connected directly to the face 12 in the direction 13, and by an annular flank face 16, planar, of revolution about the axis 2 to which it is perpendicular, which flank face 16 is turned in direction 13 and mutually connects the bottom face 15 and the inner peripheral face 11. In addition, set back inward 5 of the valve body 1 with respect to the annular recess 14 but close to the latter, the peripheral face inner 11 is hollowed out of an annular groove 17 of revolution around the axis 2 and delimited by a bottom face 18 cylindrical of revolution around the axis 2 towards which it is turned, with a diameter slightly greater than that of the inner peripheral face 11, and by two side faces 19, 20 annular, planar, of revolution about the axis 2 perpendicularly to which they are arranged, the face 19 being turned in the direction 13 and the face 20 turned in the opposite direction 21 and these two faces 19 and 20 connecting the bottom face 18 to the inner peripheral face II of the valve body 1.

 Through the groove 17, the valve body 1 receives a retaining ring 22 of the circlip type, having in particular flat annular faces 23, 24, of revolution about the axis 2 to which they are perpendicular, mutually spaced parallel to this axis 2 by a distance substantially identical to that which separates the flank faces 19 and 20 of the groove 17 parallel to this axis and turned respectively in the direction 21 and in the direction 13 so as to bear respectively against the flank face 19 of the groove 17 and against the side face 20 of the latter and thus immobilizing the stop ring 22 against any movement in the direction 21 as in the direction 13 relative to the valve body 1.

 The stop ring 22, thus engaged in the groove 18, however forms a centripetal radial projection from it, relative to the inner peripheral face 11, in particular by a coplanar extension of its face 23 towards the axis 2 Towards this axis 2, the face 23 thus extended is connected to an inner peripheral face 25 of the stop ring 22, which is cylindrical of revolution around the axis 2 with a diameter slightly smaller than that of the peripheral face. inside 11 of the valve body 1 while being considerably greater than that of the outer peripheral face 10 of the control shaft 7.

 The stop ring 22 is substantially incompressible parallel to the axis 2 and thus serves as a stop, in the direction 13, relative to the valve body 1, to a ring 26 substantially incompressible in particular parallel to the axis 2 and perpendicularly to the latter, inserted into the valve body 1 on the inside side 5 thereof relative to the stop ring 22 and having in contact with the inner peripheral face Il of the valve body 1 a face external peripheral 27 cylindrical of revolution around the axis 2 with a diameter substantially identical to that of the internal peripheral face 11 so that a guide contact is established with the longitudinal sliding, that is to say parallel to axis 2.

The ring 26 is fully defined by faces of revolution around the axis 2, namely, in addition to the outer peripheral face 27 turned in the direction of a distance from it
- A flat annular face 28, perpendicular to the axis 2 and turned in the direction 13, which face 28 is complementary to the part of the face 23 of the stop ring 22 projecting centripetally relative to the inner peripheral face It of the valve body to bear in direction 13 against this face 23 and connecting to face 27 in a centrifugal radial direction,
- A cylindrical outer peripheral face 29, rotated in a centrifugal radial direction and to which the face 28 is connected in a centripetal radial direction, which outer peripheral face 29 has a diameter substantially identical to that of the inner peripheral face 25 of the ring stop 22 to match part of this face 25 directly adjacent to face 23 of the stop ring 22,
a planar annular face 30 perpendicular to the axis 2 and turned in the direction 13, which face 30 is connected to the face 29 in a centrifugal radial direction,
- A cylindrical inner peripheral face 31 of revolution about the axis 2 towards which it is turned, with a diameter less than that of the outer peripheral face 29 of the ring 26 but much greater than that of the outer peripheral face 10 of l 'control shaft 7, this face 31 connecting to face 30 in the direction 13,
- a frustoconical face 32 facing the axis 2 and flaring in the direction 21 from its connection with the inner peripheral face 31, with an obliquity of the order of a few degrees relative to the axis 2 , which makes it possible to consider it as approximately longitudinal although it is also turned in the direction 21,
- a flat annular face 33 perpendicular to the axis 2, turned in the direction 21 and ensuring the mutual connection of the faces 32 and 27.

 Note that if the ring 26 is biased in the direction 13 relative to the valve body 1 until it comes into contact with the stop ring 22 in the direction 13, it abuts against it and then behaves as all integral with the stop ring 22 as well as with the valve body 1.

 The valve body I, with the stop ring 22 and the ring 26, constitutes the female assembly of the device according to the invention, the male assembly of which is constituted by the container 3 with seals.

 The ring 26, in abutment by its face 28 against the face 23 of the stop ring 22 itself in abutment by its face 24 against the flank face 20 of the groove 17, constitutes for the pot 3, by its face 32, a stop against a longitudinal displacement, in the direction 13, relative to the valve body 1 as well as a means ensuring the coaxiality of the pot 3 relative to the valve body 1.

For this purpose, the pot 3, which is delimited towards the inside 5 of the valve body 1, around the bore 8, by an annular, planar transverse face 34 turned in the direction 21 and having a shape of revolution around axis 2 to which it is perpendicular, is delimited by the following faces, all of revolution around axis 2
an external peripheral face 35 to which the face 34 is connected in a centrifugal radial direction, this external peripheral face 35 being cylindrical of revolution around the axis 2 and turned in the direction of a distance from it, with a diameter substantially identical to that of the inner peripheral face II of the valve body 1 so that a guide contact with relative longitudinal sliding is established between this inner peripheral face 11 and the outer peripheral face 35,
an annular transverse shoulder 36 to which the outer peripheral face 35 is connected in the direction 13, this shoulder 36 being plane, perpendicular to the axis 2 and turned in the direction 13,
- A frustoconical face 37 rotated in a centrifugal radial direction as well as in direction 13, having with respect to the axis 2 an obliquity identical to that of the face 32 of the ring 26, this face 37 connecting in the direction 21 at the shoulder 36 in a circle with a diameter intermediate between that of the outer peripheral face 35 of the pot 3 or of the inner peripheral face 11 of the valve body 1 and that of the circular connection of the faces 32 and 33 of the ring 26 while in direction 13, it ends with a circular edge 38 with a diameter less than that of the inner peripheral face 31 of the ring 26 while being much greater than that of the outer peripheral face 10 of the control shaft 7 and at any diameter of the bore 8,
- a threaded outer peripheral face 39 turned in the direction of a distance from the axis 2 with a diameter less than that of the edge 38 to which it is connected by a fillet, this diameter remaining greater than the diameter of the outer peripheral face 10 of the control shaft 7 and at any diameter of the bore 8.

 By its threaded outer peripheral face 39, the pot 3 carries a nut 40 defined in particular in the direction of a distance from the axis 2 by an outer peripheral face 41 cylindrical of revolution around this axis with an intermediate diameter between the respective diameters of the bottom face 15 of the recess 14 and of the inner peripheral face 11 of the valve body 1; this outer peripheral face 41 is connected in the direction 21 to a flat transverse face 42, annular of revolution about the axis 2 to which it is perpendicular, this face 42 thus being able to bear on the side face 16 of the recess 14 inside the bottom face 15 of which the outer peripheral face 41 of the nut 40 is housed when it is screwed onto the post 3, which brings the latter into a frank stop in the direction 13, by its frustoconical face 37, against the frustoconical face 32 of the ring 26 itself in frank abutment in the direction 13 against the stop ring 22 meanwhile in frank abutment in the direction 13 against the valve body 1 by through the throat 17.

 When these different stops are established, as shown in Figure 1, the transverse shoulder 36 of the pot 3 is spaced longitudinally of the face 33 of the ring 26, which face 33 can then be considered functionally as a shoulder of the valve body 1 , with a longitudinal distance L1 perfectly determined by the choice of the geometric characteristics of the faces 32 and 37, it being understood that this pot 3 and this ring 26 can be considered to be substantially incompressible, and more generally substantially undeformable, within the limits of use valve.

 Thus, the ring 26, by its face 33, the pot 3, by the shoulder 36 and by the area of its face 37 located between the face 33 and this shoulder 36, and the valve body 1, by the area of the face 11 also located between face 33 and shoulder 36, define between them an annular chamber 43, of revolution about the axis 2, having a perfectly determined shape, dimensions and volume, constant whatever the tightening applied at port 3, by the nut 40, on the valve body 1 through the ring 26 and the stop ring 22.

 Inside this chamber 43 are placed sealing means intended to oppose any leakage between the cup 3 and the valve body I, towards the outside 6 thereof, of a fluid under overpressure placed inside 5 of valve body 1.

 These sealing means in the example illustrated, inside the chamber 43, an annular seal 44, elastically compressible, placed in direct contact with the face 33 of the ring 26, the face 37 of the pot 3 and of the face 11 of the body 1, and a seal press 45 in the form of a ring which is substantially incompressible at least longitudinally under normal conditions of use and interposed between the seal 44 and the shoulder 36 which, in comparison with the shoulder defined by the face 33 of the ring 26, constitutes the shoulder exposed to the highest fluid pressure.

 The seal press 45, of annular shape of revolution around the axis 2, is delimited in the direction of a distance from it by a cylindrical outer peripheral face 46 of revolution around the axis 2 with a diameter substantially identical to that of the inner peripheral face 11 of the valve body 1 so that there is established between these faces 46 and 11 a sliding guide contact relative parallel to the axis 2; in direction 21, this outer peripheral face 46 is connected to a plane annular face 47 of revolution about the axis 2 to which it is perpendicular, this face 47 being turned in direction 21 and directly complementary to the shoulder 36 against which it is applied flat in this direction 21; in a centripetal radial direction, this face 47 is connected to a frustoconical face 48 of revolution around the axis 2 with a conicity identical to that of the face 32 of the ring 26 so as to match an area of the face 37 of the pot 3 directly adjacent to the shoulder 36; in direction 13, the faces 46 and 48 are connected to a flat annular face 49, of revolution about the axis 2 to which it is perpendicular, this face 49 being turned in the direction 13 and spaced longitudinally, with respect to the face 47, by a determined distance L2, less than L1, so that between this face 49 and the face 33 of the ring 26 there remains a longitudinal distance L3 itself determined.

Thus, inside the chamber 43, the seal press 45 delimits for the seal 44 an annular space of determined shapes, dimensions and volume, constant whatever the conditions of mutual tightening of the pot 3 and of the valve body I; inside this space, the seal 44 is placed in elastic prestressing of longitudinal compression perfectly determined between the faces 49 and 33 when the face 37 bears against the face 32, which establishes between the seal 33 and the face 37 of the post 3, on the one hand, and the face 11 of the valve body I, on the other hand, a sealing contact under a pressure also determined, which it will be noted that it is independent of the tightening applied longitudinally to the post 3 , by its face 37, against the valve body 1, by the face 32 of the ring 26 and by means of the latter as well as of the stop ring 22, by means of the nut 40 consequently that a contact is established between the faces 37 and 32.

 Thus, by an appropriate choice of the dimensional characteristics of the seal 44, as a function of those of the cup 3, of the ring 26 and of the seal press 45, it is possible to communicate to the seal 44 a perfectly determined longitudinal prestress, independent of the tightening obtained by means of the nut 40; it is only if the difference between the fluid pressures inside 5 of the valve body 1 and outside 6 of the latter exceeds a threshold determined as a function of this prestressing that the seal 44 can undergo, for via the seal press 45 forming the piston, an increase in longitudinal stress, which results in an increase in the pressures for applying the seal 44 against the face 37 of the container 3 and the face 11 of the body 1, forming longitudinal spans of sealing respectively on the pot 3 and on the valve body 1 between the faces 33 and 49, and consequently by a reinforcement of the resulting sealing, which limits the variations in conformation of the seal 44 and thus makes it possible to lengthen the lifespan of it.

 Preferably, the seal 44 has in the free state, that is to say in particular before it is stressed in the chamber 43, and when it is seen in section through a plane including the axis 2, a section transverse geometrically similar to that of the space remaining between the faces 11, 33, 37 and 49 after tightening of the pot 3 on the body 1 by means of the nut 40, with dimensions greater than those of this space. Such a shape makes it possible to completely fill said space in chamber 3 with the pre-stressed seal 44, but is however only a non-limiting example. As a variant, provision may be made to remove the seal press 45, in which case the seal 44 is shaped and dimensioned in relation to the shape and dimensions of the chamber 43, preferably so as to occupy the whole of the latter when there is prestressed.

 A person skilled in the art will readily understand that a sealed connection device according to the invention can know other practical embodiments in an application for sealing a pot with packings with respect to a valve body without departing from the scope of the present invention.

 Likewise, a person skilled in the art will readily understand that the application of the device according to the invention is not limited to the sealed connection of a pot with packings with a valve body but can, more generally, apply to the sealed connection of any male assembly, constituted in this example by the pot 3, with a female assembly, constituted in this example by the valve body 1.

 In particular, FIG. 2 illustrates the use of a device according to the invention for ensuring a tight connection between two pipes 50 and 51, and more precisely between a female end piece 52 welded to the pipe 50 and a male end piece 53 welded to pipe 51.

The female end piece 52 and the male end piece 53 respectively constitute the female assembly and the male assembly of the device according to the invention.

 The entire device also has in this case a symmetry of revolution about a longitudinal axis 54, common to the two pipes 50 and 51 at least in the immediate vicinity of the device according to the invention; this axis 54 will serve as a reference to the notions of longitudinality, transversality, as well as of centrifugal or centripetal radial character.

 The two end pieces 52 and 53 are tight and rigid and, while the male end piece 53 is made for this purpose in one piece, the female end piece 52 is made in the form of an assembly of several sealed parts mutually sealed and each of which has the aforementioned general symmetry of revolution.

In particular, the female end piece 52 comprises a rigid male part 55, presenting towards the axis 54 an inner peripheral face 56 of cylindrical revolution around this axis and passing through the male part 55 right through to delimit inside thereof a longitudinal passage 57 for a fluid conveyed by the pipes 50 and 51. In addition to this face 56, the male part 55 has the following faces, all of revolution around the axis 54
a transverse, annular, plane front face, perpendicular to the axis 54, turned in a longitudinal direction 59 and to which the inner peripheral face 56 is connected in this direction 59,
a cylindrical outer peripheral face 60, turned in a centrifugal radial direction and forming a longitudinal sealing surface as will appear below, this face 60 connecting in the direction 59 to the front face 58,
a planar transverse annular shoulder 61, perpendicular to the axis 54 and turned in the direction 59, the external peripheral face 60 connecting to this shoulder 61 in the direction 59,
a cylindrical outer peripheral face 62, turned in a centrifugal radial direction, with a diameter greater than that of the outer peripheral face 60, itself greater than that of the inner peripheral face 56, this outer peripheral face 62 being connected to the shoulder 61 in the direction 59,
- Another transverse annular shoulder 63 plane, perpendicular to the axis 54, rotated in a longitudinal direction 64 opposite to the direction 59, that is to say opposite the shoulder 61, the outer peripheral face 62 connecting in the direction 64 to this transverse shoulder 63,
- A cylindrical outer peripheral face 65, turned in a centrifugal radial direction, with a diameter intermediate between the respective diameters of the outer peripheral face 62 and the inner peripheral face 56, this face 65 being provided with a thread 66 and connecting in the direction 59 at the shoulder 63,
a planar transverse annular shoulder 67, perpendicular to the axis 54 and turned in the direction 64, the external peripheral face 65 connecting in the direction 64 to this annular shoulder 67,
a cylindrical outer peripheral face 68, turned in a centrifugal radial direction and connecting in the direction 59 to the shoulder 67,
a tapered annular face 69 which converges in the direction 64 while being turned both in this direction 64 and in a centrifugal radial direction, which face 69 is connected in the direction 59 to the external peripheral face 68 and in the direction 64 to the inner peripheral face 56, by means of an annular, transverse flat 70, plane, perpendicular to the axis 54 and turned in the direction 64.

 The pipe 50 abuts in the direction 59 against the annular flat 70 of the male part 55, to which it is welded by the frustoconical annular face 69 of the latter.

The female end piece 52 further comprises a rigid piece forming an envelope 71 also delimited by faces of revolution around the axis 54, namely
a cylindrical inner peripheral face 72, turned in a centripetal radial direction and having a thread 73 of the same original diameter as the thread 66 of the outer peripheral face 65 of the male part 55, with which the thread 73 is engaged,
- A transverse annular shoulder 74 plane, perpendicular to the axis 54 and rotated in the direction 59, the inner peripheral face 72 connecting in the direction 59 to this annular shoulder 74 which is in abutment flat, in the direction 59 against l 'annular shoulder 63 of the male part 55,
- A cylindrical inner peripheral face 75, turned in a centripetal radial direction and having a diameter substantially identical to that of the outer peripheral face 62 of the male part 55, this face 75 connecting in the direction 64 to the annular shoulder 74 then that it extends in the direction 59 beyond the front face 58 by locally forming two longitudinal sealing surfaces, as will appear below,
a planar transverse annular shoulder 76 perpendicular to the axis 54 and turned in the direction 59, the inner peripheral face 75 connecting in the direction 59 to this shoulder 76 by a softened edge,
a cylindrical inner peripheral face 77, turned in a centripetal radial direction with a diameter greater than that of the inner peripheral face 75, this face 77 connecting in the direction 64 to the shoulder 76 and having a thread 78,
a tapered face 79 turned both in the direction 59 and in a centripetal radial direction, this face 79 widening in the direction 59 from the inner peripheral face 77 which is connected to it in this direction 59,
a plane annular front face, transverse 80 plane, perpendicular to the axis 54 and turned in the direction 59, the frustoconical face 79 connecting to this front face 80 in the direction 59,
- a set of faces 81, 82, 83, 84, 85 cylindrical or frustoconical, rotated in centrifugal radial direction as well as, for some, in direction 59 or in direction 64, which faces 81 to 85 have a geometry indifferent to the gaze of the present invention and connect the outer peripheral limit of the face 80 to the outer peripheral limit of a front face 86 annular, transverse, plane, perpendicular to the axis 54 and turned in the direction 64, which face 86 is connected in centripetal radial direction to the inner peripheral face 72, opposite the connection of the latter with the shoulder 74.

 At the junction between the front face 80 and the set of faces 81 to 85, and more precisely in the faces 81 and 82, notches 87 are provided which serve to immobilize the rotation about the axis 54, relative to the envelope 71, a lock washer 88 for a nut 89 screwed into the envelope 71 by the thread 78, as will be described below, to constitute means for mutual tightening of the two end pieces 52 and 53.

The female end piece 52 also comprises a ring 90 which is substantially incompressible, in particular longitudinally, inserted in the casing 71 and abutting in the direction 64 against the front face 58, which ring 90 is also delimited by faces of revolution about the axis 54 , namely by
- A cylindrical inner peripheral face 91, turned in a centripetal radial direction and having a diameter identical to that of the inner peripheral face 56 of the male part 55 so as to delimit a passage of fluid 92 passing through the ring 90 longitudinally right through and consequently extending the fluid passage 57 of the male part 55,
an annular, transverse, planar front face 93, perpendicular to the axis 54 and turned in the direction 64, the inner peripheral face 71 being connected in this direction 64 to this face 93,
an outer peripheral face 94 which is cylindrical and turned in a centrifugal radial direction, with a diameter substantially identical to that of the outer peripheral face 62 of the male part 55 and to that of the inner peripheral face 75 of the casing 71, this face 94 connecting in the direction 64 to the front face 93,
another annular front face 95 which is annular, transverse, planar, perpendicular to the axis 54 and turned in the direction 59, the external peripheral face 94 and the internal peripheral face 91 being connected to this front face 95 in the direction 59.

 The front face 93 of the ring 90 is in abutment flat abutment, in the direction 64, against the front face 58 of the male part 55 longitudinally, the distance separating from the front faces 93 and 95 of the ring 93 is less at the longitudinal value of the overhang that the inner peripheral face 75 of the casing 71 forms with respect to the front face 58 of the male part 55 so that the ring 90 is in guide contact with free longitudinal sliding , by its outer peripheral face 94, with the inner peripheral face 75 of the casing 71, and that this face 75 forms a longitudinal overhang, in the direction 59, relative to the front face 95 of the ring 90.

 The abovementioned support of the front face 93 of the ring 90 against the front face 58 of the male part 55 is effected by an annular zone of this front face 93 adjacent to the connection of the latter with the inner peripheral face 91 of the ring 90 while the remaining annular zone of this front face 93, adjoining the junction of the latter with the external peripheral face 94 of the ring 90, forms a radial centrifugal projection relative to the external peripheral face 60 of the part male 55 a shoulder turned in the direction 64 and disposed longitudinally opposite the shoulder 61 of the male part 55, at a determined longitudinal distance L4 from this shoulder 61.

 Thus, the front face 93 of the ring 90, by its annular zone adjoining its connection with the external peripheral face 94 of the latter, delimits with the shoulder 61 of the male part 55, the external peripheral face 60 of the latter ci and part of the inner peripheral face 75 of the casing 71 a chamber 96 of determined shape, dimensions and volume, constant whatever the stresses to which the male part 55, the ring 90 and the casing 71 are subjected under normal conditions of use, it being understood that the male part 55, the ring 90 and the casing 71 are non-deformable under such normal conditions of use.

 This chamber 96, comparable in this with chamber 43 of the device according to the invention described with reference to FIG. 1, encloses a seal 97, elastically compressible in particular longitudinally, and a seal press 98, meanwhile substantially incompressible in particular longitudinally in normal conditions of use, both annular of revolution around the axis 54.

 The joint press 98 is adjacent to that of the shoulders delimiting the chamber 96, namely the shoulder 61 and the shoulder formed by the zone of the front face 93 of the ring 90 adjoining the junction of the latter with the peripheral face. outer 94 of this ring 90, which is exposed to the highest fluid pressure, namely in the example illustrated the aforementioned zone of the front face 93 of the ring 90, which is exposed to the pressure of the fluid passing through the passages 57 and 92, greater than the pressure prevailing outside 99 of the pipes 50; 51 and of the device according to the invention.

 More specifically, the seal press 98 has in contact, flat, with the front face 93 of the ring 90 a transverse annular face 100 plane, perpendicular to the axis 54 and turned in the direction 59 while it presents towards the 'shoulder 61, in the direction 64, another annular face, transverse 101 also planar and perpendicular to the axis 54, spaced from the face 100 by a distance L5 less than the distance L4 so that remains between this face 101 and the shoulder 61 a longitudinal distance L6 ;; the two transverse annular faces 100, 101 are connected to each other by an inner peripheral face 102 and by an outer peripheral face 103, one and the other cylindrical of revolution around the axis 54 and rotated respectively in centripetal radial direction and in direction centrifugal radial, with respective diameters substantially equal respectively to that of the outer peripheral face 65 of the male part 55 and to that of the inner peripheral face 75 of the casing 71 so that sliding guide contacts are established relative longitudinal; the inner 102 and outer 103 peripheral faces are connected to the transverse annular face 101 by sharp edges whereas, as illustrated, they can be connected to the transverse face 100 by softened edges.

 In accordance with the present invention, the annular seal 97, which is elastically compressible, in particular longitudinally, is held in longitudinal prestress between the shoulder 61 of the male part 55 and the transverse face 101 of the seal press 96, meanwhile substantially incompressible longitudinally and in support. in the direction 59 against the face 93 of the ring 93 itself in abutment by this same face 93, in the direction 64, against the front face 58 of the male part 55.

 Thanks to an appropriate conformation and dimensioning of the seal 97, easily determinable by a skilled person depending on the one hand on the material constituting this seal 97 and on the other hand on the desired seal, the seal 97 applies under a pressure capable of establishing a sealing contact on the one hand in a centripetal radial direction against the external peripheral face 60 of the male part 55 and on the other hand in a centrifugal radial direction against the internal peripheral face 75 of the casing 71, which faces 60 and 75 thus locally form longitudinal sealing surfaces. The seal 97 thus prevents any leakage to the outside 99, between the casing 71 and the male part 55, of the overpressure fluid passing through the passages 57 and 92 and liable to creep into the chamber 96 We note that it is only in the event that the pressure of this fluid, acting on the seal press 98, overcompensates this preload that the seal 97 can be caused to deform under the action of the latter, acting as a piston, being noted that it then undergoes an increase in longitudinal compression resulting in an application under higher pressure against the longitudinal sealing surfaces constituted respectively by the outer peripheral face 60 of the male part 55 and by the face inner peripheral 75 of the casing 71, which increases the tightness as the pressure of the fluid passing through the passages 57 and 92 itself increases. For example, the seal 97 before prestressing presents, when seen in section through a plane including the axis 54, a shape geometrically similar to that of the remaining space, in the chamber 96, between the seal press 98, the faces 60 and 75 and the shoulder 61, with dimensions greater than those of this space so that the prestressed joint 37 completely fills this space; however, other forms of seal 97 can be chosen without departing from the scope of the present invention. As a variant, it is also possible to eliminate the seal press 98 by shaping and dimensioning the seal 97 in relation to the shape and dimensions of the chamber 96, preferably in such a way that the seal 97 in prestress fully occupies the latter.

 Naturally, the longitudinal compression preload imposed on the joint 97 tends to drive the ring 90 in the direction of a longitudinal distance from the male part 55, that is to say in the direction 59, and the ring 90 must be retained in abutment against the front face 58 of the male part 55, in practice by the male end piece 53 itself retained longitudinally, relative to the casing 71, by the nut 89.

 To this end, if we consider a plane 104 perpendicular to the axis 54 and constituting for the ring 90 a plane of symmetry, that is to say a plane equidistant from the two end faces 93 and 95 of the ring 90, the male end piece 53 constitutes the specular image of the male part 55 with respect to the plane 104, except that it does not have a thread corresponding to the thread 65.

Therefore, we will not describe in detail the male end piece 53 which will only be indicated as being rigid and delimited by an inner peripheral face 105 constituting the specular image of the inner peripheral face 56 of the male part 55 and delimiting a passage 106 passing longitudinally through the male end piece 53 right through to extend the passages 57 and 92, a front face 107 constituting the specular image of the front face 58 of the male part 55 and bearing longitudinally, in the direction 64, against an annular zone of the front face 95 of the ring 90 adjoining the junction of the latter with the external peripheral face 91, an external peripheral face 108 constituting the specular image of the external peripheral face 60 of the male part 55, an annular transverse shoulder 109 constituting the specular image of the shoulder 61 of the part 55, an outer peripheral face 110 constituting the specul area of the outer peripheral face 62 of the male part 55 and of which it is noted that, owing to appropriate longitudinal dimensions, easily determined by a
A person skilled in the art, it is located partly in contact with the inner peripheral face 75 of the casing 71 and partly opposite the inner peripheral face 77 thereof, overlapping the shoulder 76, a transverse annular shoulder 111 constituting the specular image of the shoulder 63, an outer peripheral face 112 constituting the specular image of the outer peripheral face 65 of the male part 55 except that it is smooth instead of being provided with a thread similar to thread 66, a shoulder 113 constituting the specular image of the shoulder 67, an outer peripheral face 114 constituting the specular image of the outer peripheral face 68, a frustoconical annular face 115 constituting the specular image of the face 69 and a flat 116 constituting the specular image of the flat 70.

 The pipe 51 abuts in the direction 64 against the annular flat 116 of the male end piece 53, to which it is welded by the frustoconical annular face 115 of the latter.

 The nut 89, arranged coaxially around the outer peripheral face 112 of the male end piece 53, has opposite it an inner peripheral face 117 cylindrical of revolution around the axis 54 with a diameter intermediate between the respective diameters external peripheral faces 112 and 110 of the male end piece 53, this diameter however preferably being as close as possible to that of the external peripheral face 112. In direction 64, this internal peripheral face 117 is connected to a front face 118 annular, planar, of revolution about the axis 54 to which it is perpendicular, this face 118 being turned in the direction 64 and connecting the inner peripheral face 117 to an outer peripheral face 118 cylindrical of revolution around the axis 54, turned in centrifugal radial direction and having a thread 119 of the same original diameter as the internal thread 78 of the face 77 and complementary e of this tapping 78, with which the thread 119 is engaged. The outer peripheral face 118 of the nut 89, thus connecting in the direction 64 to the front face 118 thereof, is connected in the direction 59 to a transverse annular shoulder 120 of the nut 89, which shoulder is of revolution around the axis 54, plane and perpendicular thereto, and turned in the direction 64 so as to bear in this direction on the front face 80 of the casing 71 by means of the lock washer 88 , which immobilizes the nut 89 against unscrewing relative to the casing 71. The shoulder 120 is connected to the inner peripheral face 117 of the nut 89 by a set of faces 121, 122, 123 having respective forms of revolution around the axis 54, and indifferent with regard to the present invention.

 Longitudinally, the outer peripheral face 118 of the nut 89 is dimensioned such that when the shoulder 120 of the latter abuts against the front face 80 of the casing 71 by means of the lock washer 88, the front face 118 applies to the transverse shoulder 111 of the male end piece 53 a thrust in the direction 64, suitable for keeping the male end piece 53 in abutment of abutment abrupt, by its front face 107, against the front face 95 of the ring 90, itself in frank abutment support, by its front face 93 against the front face 58 of the male part 55, in this same direction 64. Thus is the longitudinal prestressing of the seal 97 inside of room 96.

 In addition, a longitudinal preload is thus ensured for an elastically compressible seal 124, in particular longitudinally, constituting the specular image of the annular seal 97 and arranged, as is a seal press 125, meanwhile incompressible longitudinally under normal conditions of use and constituting the specular image of the seal press 98, in a chamber 126 which constitutes the specular image of the chamber 96 and is delimited by the shoulder 109, against which the seal 124 bears directly in the direction 59, by the face outer peripheral 108 of the male end piece 53 and the inner peripheral face 75 of the casing 71, which faces constitute longitudinal sealing surfaces insofar as the seal 124 in longitudinal compression is supported therein under respectively centripetal radial pressure and centrifugal suitable for sealing, and by an annular zone of the front face 95 of the ring 92 adjoining the junction of this face 95 with the outer peripheral face 94 of this ring 90, around the annular zone of this front face 95 on which the front face 107 of the male end piece 53 rests flat. This annular zone of the front face 95 which delimits the chamber 126 constitutes, facing the shoulder 109, a support shoulder for an annular transverse face 127 of the clamp 125, which constitutes the specular image of the face 100 of the seal press 98 while the seal press 125 offers the support of the seal 124 in the direction 64 an annular transverse face 128 constituting the specular image of the face 101 of the seal press 98, these two annular transverse faces 127 and 128 being mutually connected by inner peripheral faces 129 and outer 130 constituting the respective specular images of the inner 102 and outer 103 peripheral surfaces of the seal press 98 under conditions suitable for ensuring a guide contact in the longitudinal sliding of the seal press 125 with the inner peripheral face 75 of the envelope 71.

 The distances L4, L5, L6 are found identically, respectively between the face 95 and the shoulder 109, between the face 95 or 127 and the face 128, and between the face 128 and the shoulder 109.

 The seal 124, suitably shaped and dimensioned according to the nature of the material constituting it and the desired prestress in view of the desired sealing effect, easily determinable by a person skilled in the art, has the function of preventing leaks of the fluid passing through the passages 57, 92 and 106, towards the outside 99, between the male end piece 53 and the casing 71 of the female end piece 52.

As in the case of the seal 97 to which it is preferably identical, including as regards its conformation and its dimensioning in the absence of prestressing, it does not deform as long as the stress it receives from the fluid does not exceed a threshold predetermined by its prestress; if the stress thus received from the fluid exceeds this threshold, it is subjected by the clamp 125, forming a piston, to an increase in longitudinal stress which increases its contact pressure with the longitudinal sealing surfaces formed respectively by the outer peripheral face 108 of the male end piece 53 and by the inner peripheral face 75 of the casing 71, which increases the seal which it provides.

 It will be noted that only the seal 124 plays a role in the sealing of the male end piece 53 relative to the female end piece 52, and that the seal 97 has the sole role of sealing two parts of this female end piece 52, namely the casing 71 and the male part 55 which could give rise to leakage of fluid therebetween.

 Instead of producing the female end piece 52 by assembling several parts capable of giving rise to leakage of fluid therebetween, it is also possible, without departing from the scope of the present invention, to produce it in one piece as shown in FIG. 'illustrated in Figure 3, in which case the seal 97, the seal press 98, and the chamber 96 for receiving them become superfluous.

 FIG. 3 thus shows a female assembly 131 produced in a single sealed and rigid piece, receiving by interlocking and welding a pipe 50 for the purpose of sealingly connecting the latter with a pipe 51, meanwhile fitted and welded to a male end piece 53 at all points identical to that which has been described with reference to FIG. 2 and itself assembled to the female end piece 131 by means of a nut 89 and a lock washer 88 at all points identical, respectively, to the nut and to the lock washer described with reference to FIG. 2; the different parts of the male end piece 53, of the lock washer 88 and of the nut 89 are therefore designated by the same references as in FIG. 2 to the description of which reference will be made to their subject.

The female end piece 131 is in the case of this embodiment in the form of a single piece comprising the male part 55, the ring 90 and the casing 71 previously described, in the sense that it has a general shape of revolution around axis 54, defined by:
a cylindrical inner peripheral face 132 reproducing the geometry of the respective inner peripheral faces 56 and 91 of the male part 55 and the ring 90 and delimiting a passage 133 passing through the female end piece 131 longitudinally right through to correspond to the passages 57 and 92,
- A front face 133 identical to the front face 95 of the ring 90 and serving, by an annular zone adjoining the junction of this front face 133 with the inner peripheral face 132, to support the front face 107 of the male end piece 53 flat, in the direction 64, on the female end piece 131,
an inner peripheral face 134 reproducing the geometry of the part of the inner peripheral face 75 of the casing 71 situated in a longitudinal overhang between the front face 95 of the ring 90 and the shoulder 76 of the casing 71, so as, on the one hand, to define with the external peripheral face 108 of the male end piece 53, the transverse shoulder 109 of the latter, and the annular zone of the front face 133 of the female end piece 131 adjoining the junction of this face with the inner peripheral face 134 and thereby forming a transverse shoulder placed longitudinally opposite the shoulder 109, a chamber 150 at all points identical to the chamber 129 and receiving the seal 124 and the press joint 125 described above, the latter resting by its face 127 against the face 133, and on the other hand to be placed in contact with the outer peripheral face 110 of the male end piece 53 in a guide relation to sliding lon relative gitudinal,
a shoulder 135 at all points identical to the shoulder 76 and arranged like the latter so as to be overlapped with respect to the outer peripheral face 110 of the male end piece 53 when the latter is supported by its front face 107 against the front face 133 of the female end piece 131,
an inner peripheral face 136 identical to the inner peripheral face 77 of the casing 71 and, like it, having a thread 137 receiving the thread 119 of the outer peripheral face 118 of the nut 89,
- a frustoconical face 138, identical to face 79,
a front face 139 identical to the face 80 and, like this one, serving as a support for the locking washer 88,
- faces 140, 141, 142, 143, 144, 145 reproducing identically the faces 81, 82, 83, 84, 85, 86 of the envelope 71,
an annular shoulder 146 identical to the shoulder 67 of the male part 55,
an outer peripheral face 147 identical to the face 68 of the male part 55,
an annular face 148 and a flat 149 identical respectively to the frustoconical face 69 and to the flat 70 of the male part 55, and serving respectively as a counterpart for welding and abutment, in the direction 59 opposite to the direction 64, for the pipe 50 .

 Naturally, the seal 108 and the seal press 109 work, in this embodiment of the female end piece, identically to their working mode in the embodiment of the female end piece described with reference to FIG. 2.

 A person skilled in the art will readily understand that the three embodiments of the invention which have just been described in the case of two particular applications are only non-limiting examples as well in terms of embodiment of a device according to the invention in terms of application of such a device.

Claims (10)

 1. A sealed connection device for two sealed assemblies (1, 3, 52, 53, 131) having the same longitudinal axis (2, 54) determined, as follows:  - a male assembly (3, 53) having a transverse annular shoulder (36, 109) which is rotated in a determined longitudinal direction (13, 64) and is connected, in a centripetal radial direction, to an annular, longitudinal bearing sealing (37, 108) rotated in a centrifugal radial direction,  - a female assembly (1, 52, 131) having a transverse annular shoulder (33, 95, 133) which is turned in the direction (21, 59) opposite to said determined longitudinal direction (13, 64), faces the transverse shoulder (36, 109) of the male assembly (3, 53), and is connected, in a centrifugal radial direction, to an annular, longitudinal sealing surface (11, 75, 134) turned in a radial direction centripetal and facing the longitudinal sealing surface (37, 108) of the male assembly (3, 53),  said device comprising an elastically compressible annular seal (44, 124) interposed between the transverse shoulders (33, 36, 95, 109, 133) and longitudinal sealing surfaces (11, 37, 75, 108, 134) of the two assemblies ( 1, 3, 52, 53, 131) and clamping means (40, 89) for applying to the two assemblies (1, 3, 52, 53, 131) a longitudinal stress of mutual approach of the transverse shoulders (33, 36, 95, 109, 133) so as to put the annular seal (44, 124) in longitudinal prestress between the latter and to press it radially against the longitudinal sealing surfaces (11, 37, 75, 108, 134),  characterized in that it includes means of frank mechanical stop (faces 32 and 37, faces 95 and 107) between the two assemblies (1, 3, 52, 53, 131) to impose on said mutual approximation a limit such as the shoulders transverse (33, 36, 95, 109, 133) of the two sets (1, 3, 52, 53, 131) are mutually spaced along longitudinally, after tightening, by a determined longitudinal distance (L1, L4), corresponding to a determined longitudinal prestressing of the annular seal (44, 124).  2. Device according to claim 1, characterized in that it has a general symmetry of revolution around said axis (2, 54).  3. Device according to any one of claims 1 and 2, characterized in that, in the case where the transverse shoulders (35, 36, 95, 109, 133) are exposed to different fluid pressures, it comprises a press annular seal (45, 125), substantially incompressible longitudinally, between the annular seal (44, 124) and the transverse shoulder (36, 95, 133) subjected to the highest fluid pressure.  4. Device according to any one of claims 1 to 3, characterized in that the abutment means (32, 37, 95, 107) are located in centripetal withdrawal relative to the longitudinal sealing surface (37, 108) of the male assembly (3, 53) and to the transverse shoulder (33, 95) of the female assembly.  5. Device according to claim 4, characterized in that the longitudinal sealing surface (11) of the female assembly (3) is parallel to the axis (2), in that the longitudinal sealing surface (37 ) of the male assembly (3) is oblique to the axis (2), which it approaches in said determined longitudinal direction (13), and in that the stop means (32, 37) comprise  on the one hand, a direct annular extension (37) of the longitudinal sealing surface (37) of the male assembly (3),  - on the other hand a surface (32) complementary to said extension (37), arranged on the female assembly (1) and placed back in said determined longitudinal direction (13) relative to the transverse shoulder (33) of the female set (I).  6. Device according to claim 4, characterized in that the longitudinal sealing surfaces (75, 108, 134) of the two assemblies (52, 53, 131) are parallel to the axis (54) and in that the means stop (95, 107, 133) have  - firstly a direct annular extension (95, 33) of the transverse shoulder (95, 133) of the female assembly (52, 131),  - On the other hand an annular surface (107) complementary to said extension (95, 133), arranged on the male assembly (53) and to which the longitudinal sealing surface (108) of the male assembly (53) is connects in said determined longitudinal direction (64).  7. Device according to claim 6, characterized in that the female assembly (52) comprises  - A longitudinal annular casing (71) constituting the longitudinal sealing surface (75) of the female assembly (52), which extends beyond the transverse shoulder (95) of the female assembly (52) in direction (59) opposite to said determined longitudinal direction (64),  an added transverse ring (90) constituting the transverse shoulder (95) of the female assembly (52) and said extension (95) and moreover having a transverse face (93) turned in said determined longitudinal direction (64), opposite the transverse shoulder (95) of the female assembly (52) and said extension (95), and a longitudinal outer peripheral face (94) to which the transverse shoulder (95) of the female assembly (52) and said transverse face (93) of the ring (90) are connected in a centrifugal radial direction and which is placed in free contact with the longitudinal sealing surface (75) of the female assembly (52),  - A male part (53) located longitudinally opposite the male assembly (53) relative to the ring (90) and secured to the casing (71), said male part (55) comprising  * a transverse annular shoulder (61) which is turned in the direction (59) opposite to said determined longitudinal direction (64), faces the transverse face (93) of the ring (90) and is connected, in a centripetal radial direction , to the longitudinal sealing surface (75) of the female assembly (52),  a transverse annular surface (58) which is turned in a direction (59) opposite to said determined longitudinal direction (64), and offset on the one hand longitudinally by a determined longitudinal distance (L4), in said opposite direction (59), and on the other hand in a centripetal radial direction with respect to the transverse shoulder (61) of the male part (55) and faces the transverse face (93) of the ring (90) against which it is in longitudinal abutment after tightening,  * an annular, longitudinal sealing surface (60) which is rotated in a centrifugal radial direction, faces the longitudinal sealing surface (75) of the female assembly (52) and mutually connects the transverse surface (58) of the male part (55) and the transverse shoulder (61) of the male part (55),  - And another elastically compressible annular seal (97) interposed in determined longitudinal preload, after tightening, between the transverse shoulder (61) of the male part (55), the transverse face (93) of the ring (90) and the longitudinal sealing surfaces (75, 60) of the female assembly (52) and of the male part (55).  8. Device according to claim 7, characterized in that, in the case where the transverse face (93) of the ring (90) and the transverse shoulder (61) of the male part (55) are exposed to pressures of different fluids, it comprises an annular seal press (98), substantially incompressible longitudinally, between the other annular seal (97) and the transverse face (93) of the ring (90) or the transverse shoulder (61) of the male part (55), respectively, which is subjected to the highest fluid pressure  9. Application of a device according to claim 5 to the sealed connection of a valve body (1), constituting the female assembly, and of a container (3) with seals (4) receiving a shaft ( 7) valve control and constituting the male assembly.  10. Application of a device according to any one of claims 6 to 8 to the sealed connection of two pipes (50, 51), one of which (51) is tightly secured to the male assembly (53) and of which the other (50) is tightly secured to the female assembly (131), respectively the male part (55) thereof (52).