Valve and associated fitting including such a valve for a fluid line coupling device

Abstract

Valve and associated fitting comprising such a valve for a fluid line coupling device. The invention relates primarily to a valve (7) for fitting a fluid line coupling device, which extends along a main longitudinal axis (XX') and which has a valve head (8) surmounting a stem (17), characterized in that said valve head (8) has a free end (11) extending towards a junction base (15) with the stem (17) to a coaxial shoulder (12) which, together with the base (15), defines a coaxial collar (14) and which extends to an annular perimeter edge (13) having a diameter greater than the diameter of said free end (11), and in that the annular perimeter edge (13) is made of fluoropolymer. The invention further relates to a fitting incorporating such a valve and to a fluid line coupling device incorporating such a fitting. Figure to be published with the abbreviation: Figure 4

Description

Title of the invention: Valve and associated fitting comprising such a valve for a fluid conduit coupling device. TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of fluid conduit coupling devices, and more particularly of cryogenic fluid. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] Coupling devices are known to transfer fluids, including cryogenic fluids, from a storage tank to a mobile use tank.

[0003] To achieve this, the coupling device comprises a first male fitting and a second female fitting, which are poppet valves whose ends are butted together. Each valve has a fluid passage orifice from which a poppet protrudes, supported by a spring. In the rest position, the spring keeps the poppets engaged in their respective fluid passage orifices, the fitting thus being in the closed position. Coupling the fittings causes the springs, and therefore the poppets, to move. Under the effect of the coupling, the movement of the poppets creates a passage orifice. The device as a whole then moves from a position in which both male and female fittings are closed to a position in which both male and female fittings are open, ensuring the transfer of fluid through the coupling device.

[0004] The male fitting of the device often presents specific constraints related to the characteristics of its spring and the geometry of its body and valve. The male fitting must therefore be adapted to the female fitting.

[0005] The male fitting is subjected to more than 10,000 cycles during its service life and is subjected to temperature variations ranging from ambient temperature to -196°C. These stresses can degrade the sealing performance of the fitting, leading to premature replacement or malfunction.

[0006] Known fittings which generally have a peripheral seal at the level of the support flange of the poppet valve against the inner face of the fitting, often cause a number of problems including a variable leakage rate close to the limit criterion defined at 103 mbar.l / s, poor replacement of the poppet in the closed position, as well as a risk of dislodging of the support flange.

[0007] In this context, the invention relates to a valve and a fitting comprising such a valve and forming the male part of a fluid coupling device that overcomes the aforementioned drawbacks by offering a sufficiently high level of sealing to ensure optimum performance throughout the part's service life. The invention is not, however, limited to a valve to be integrated into a male fitting, but also relates to a valve that adapts to any fitting. Summary of the invention

[0008] For this purpose, the valve (7,7a,7b) for connecting a fluid line coupling device, which extends along a main longitudinal axis (XX') and which has a valve head (8,8a,8b) surmounting a stem (17), is essentially characterized in that said valve head (8,8a,8b) has a free end (11) extending towards a junction base (15) with the stem (17) up to a coaxial shoulder (12) which delimits with the base (15) a coaxial collar (14,14a,14b) and which extends up to an annular perimeter edge (13) having a diameter greater than the diameter of said free end (11), and in that the annular perimeter edge (13) is made of fluorinated thermoplastic polymer.

[0009] The valve of the invention may also include the following optional features considered individually or according to all possible technical combinations: • the coaxial shoulder (12) extends transversely to the longitudinal axis (XX') up to the annular perimeter edge (13). • according to one variant, the coaxial collar (14b) is cylindrical and extends longitudinally from the annular perimeter edge (13) to the junction base (15). • according to another variant, the coaxial collar (14,14a) has a first frustoconical part (161,161a) which extends longitudinally, widening from the annular perimeter edge (13) to a second cylindrical part (162,162a) which extends longitudinally to the junction base (15) • The fluorinated thermoplastic polymer is polychlorotrifluoroethylene. • The valve is made entirely of polychlorotrifluoroethylene. • the surface area of ​​the annular perimeter edge (13) is less than 12mm2.

[0010] Another aspect of the invention relates to a fitting intended to form the male part of a fluid conduit coupling device, and comprising: • a longitudinal body (2) extending from a junction end to a conduit (3) to a coupling end (4) to a second cooperating fitting of the coupling device, which coupling end (4) presents a fluid passage orifice (5) in fluidic communication with a flow channel (6) formed in the longitudinal body (2) and which extends from the coupling end (4) to the junction end (3), • a valve (7, 7a, 7b) as previously defined, disposed in the flow channel (6) of the longitudinal body (2), the principal axis of which extends along the principal axis (XX') of the longitudinal body (2) of the fitting (1), and which comprises a valve head (8, 8a, 8b) surmounting a stem (17), which valve head (8, 8a, 8b) is located at the passage orifice (5) of the coupling end (4) of the longitudinal body (2), extends longitudinally between a free end (11) and a junction base (15) with the longitudinal stem (17), and is displaceable longitudinally in the flow channel (6) by the application of a force (F) on said valve head (8, 8a, 8b) by actuation means (9) between a clear position in which the passage orifice (5) is open, and a closed, watertight position in which the passage orifice (5) is sealed by a watertight contact between the valve head (8, 8a,8b) and a truncated conical valve head seat (10) formed in the longitudinal body (2) and in the internal extension of the passage orifice (5), the free closing end (11) of the valve (1) extending into the passage orifice (5) by projecting from the coupling end (4), , the fitting being characterized in that the free end of the sealing end (11) of the valve head (8,8a,8b) extends towards the junction base (15) to a coaxial shoulder (12) which delimits with the base (15) a coaxial collar (14,14a,14b) and which extends to an annular perimeter edge (13) having a diameter greater than the diameter of said free end (11), which annular perimeter edge (13) constitutes the only sealing contact bearing surface between the valve head (8, 8a,8b) and the valve head seat (10) when the valve head (8, 8a,8b) is in its sealing position, and in that the annular perimeter edge (13) is made of fluorinated thermoplastic polymer.

[0011] The fitting of the invention may also include the following optional features considered individually or according to all possible technical combinations: • the coaxial shoulder (12) of the valve head (8,8a,8b) of the valve (7,7a,7b) extends transversely to the longitudinal axis (XX') up to the annular perimeter edge (13). • according to one variant, the coaxial collar (14b) of the valve head (8,8a,8b) of the valve (7,7a,7b) is cylindrical and extends longitudinally from the annular perimeter edge (13) to the junction base (15). • according to another variant, the coaxial collar (14,14a) of the valve head (8,8a,8b) of the valve (7,7a,7b) has a first frustoconical part (161,161a) which extends longitudinally, widening from the annular perimeter edge (13) to a second cylindrical part (162,162a) which extends longitudinally to the junction base (15) • the base angle (A) of the first frustoconical part (161,161a) is less than the base angle (B) of the valve head seat (10) so that the annular edge (13) remains the only sealing contact bearing surface between the valve head (8,8a) and the valve head seat (10) when the valve head (8,8a) is in its sealing grip position. • The fluorinated thermoplastic polymer is polychlorotrifluoroethylene. • the valve (7,7a,7b) is made of polychlorotrifluoroethylene. • The valve head seat (10) is made of stainless steel. • the longitudinal body (2) of said fitting (1) is made of stainless steel. The surface area (S) of the annular edge (13) is defined according to the following formula [Math 6]: c F Formula 6 ô s z0 1RtE Where is the thickness of the coaxial collar (14,14a) in millimeters? F' 1m is the normal force on the surface of the annular perimeter edge (13) in Newtons resulting from the application of the force of the actuation means (9) applied on the base (15) of the valve head (8,8a,8b) E is the modulus of elasticity of the material constituting the annular perimeter edge (13) in MPa, and Rt is the surface roughness of the valve head seat (10) of the body (2) of the fitting (1). • the valve (7,7a,7b) is made of polychlorotrifluoroethylene with a modulus of elasticity between 1300 and 1500 MPa, the longitudinal body (2) of the fitting (1) is made of stainless steel with a roughness Rt of less than 4 pm, preferably less than or equal to 2 pm, the force F' 1m is between 25 and 45 Newtons, the thickness of the coaxial collar is between 2 and 3 millimeters and the surface of the annular edge (13) is less than 34 mm2. • the surface of the annular edge (13) is less than 12 mm2 and in that the roughness Rt of the valve head seat (10) is less than or equal to 2 pm. • the means for actuation (9) of the movement of the valve head (9) include a spring (9) which extends to the base (15) of the collar (14) of the valve head (8,8a,8b) and which forces the valve head (8,8a,8b) towards its sealing position by applying a force parallel to the longitudinal axis (XX') of the fitting (1) and the valve (7).

[0012] Another aspect of the invention relates to a fluid conduit coupling device, which is characterized in that it comprises a first fitting according to any one of claims 8 to 20 forming a male part and a second cooperating fitting (1') forming a female part, the second fitting comprising: - a longitudinal body (2') which extends from a junction end (3') to a second conduit (3') to a coupling end (4') which surrounds the coupling end (4) of the first fitting (1), which coupling end (4') has a fluid passage orifice (5') in fluidic communication with a flow channel (6') formed in the longitudinal body (2') and which extends from the coupling end (4') to the junction end (3'), - a valve (7') disposed in the flow channel (6') of the longitudinal body (2') and comprising a valve head (8') located at the passage orifice (5') of the coupling end (4') of the longitudinal body (2'), and which is movable longitudinally in the flow channel (6') by actuation means (9') between a clear position in which the passage orifice (5') is open, and a sealed position in which the passage orifice (5') is closed by a sealed contact between the valve head (8') and a truncated conical valve head seat (10') provided in the longitudinal body (2') and in the extension of the passage orifice (5'), and in that the respective valve heads (8,8a,8b;8') of the first and second fittings (1,1') are in longitudinal contact support and are alternately subjected, by the actuation means (9) associated with the valve head (8,8a,8b) of the first fitting (1) and the actuation means (9') associated with the valve head (8') of the second fitting (1'), in cooperation with the relative position of the respective coupling ends (4,4') of the first (1) and second (1') fittings, to a concomitant position of clearance of the fluid passage orifices (5,5') of the first (1) and second (1') fittings, and to a concomitant position of closure of the fluid passage orifices (5,5') of the first (1) and second (1') fittings. ;

[0013] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0014] Other features and advantages of the invention will become apparent from the following description, with reference to the accompanying figures, which illustrate:

[0015] [Fig.1] Fig.1 is a schematic longitudinal cross-sectional representation of the fitting of the invention when the valve, according to a first variant, is in the position of closing the fluid passage orifice;

[0016] [Fig.2] The [Fig.2] is a schematic longitudinal sectional representation of the fluid conduit coupling device of the invention when the fluid passage orifices of the first and second fittings are simultaneously closed, the valve of the invention, according to the first variant, of the fitting of the invention being in the closed position;

[0017] [Fig.3] The [Fig.3] is a schematic longitudinal cross-sectional representation of the fluid connection area of ​​the fluid conduit coupling device of the invention when the fluid passage orifices of the first and second fittings are simultaneously cleared, the valve of the invention, according to the first variant, of the fitting of the invention being in the cleared position;

[0018] [Fig.4] The [Fig.4] is a schematic longitudinal sectional representation of a part of the fitting of the invention illustrating the coupling end of the fitting when the valve of the invention, according to the first variant, is in the closed, sealed position in which the fluid passage orifice is blocked;

[0019] [Fig.5] The [Fig.5] is a schematic perspective representation of the valve of the invention according to the first embodiment and an enlarged part of the annular collar of the valve;

[0020] [Fig.6] The [Fig.6] is a schematic side view representation of the valve of the invention according to a second embodiment and an enlarged part of the upper part of the annular collar of the valve;

[0021] [Fig.7] Fig.7 is a schematic perspective and elevation representation of the valve of the invention according to the second embodiment; and

[0022] [Fig.8] The [Fig.8] is a schematic perspective representation of the valve of the invention according to a third embodiment. DETAILED DESCRIPTION

[0023] It is first specified that in the figures, the same references designate the same elements regardless of the figure in which they appear and regardless of the form of representation of these elements. Similarly, if elements are not specifically referenced in one of the figures, their references can easily be found by referring to another figure.

[0024] It is also specified that the figures represent variants of the invention but that there may be other embodiments which meet the definition of the invention.

[0025] The present invention relates primarily to a valve adapted to form part of a male fitting, itself part of a fluid line coupling device. The invention also applies to a valve adapted to form part of a female fitting of a fluid line coupling device.

[0026] Contrary to known fittings which provide, in order to ensure the sealing of the coupling device, a maximization of the contact surface between the valve head and the internal contact surface of the fitting, as well as, where appropriate, the addition of a sealing gasket, the invention provides a valve whose contact surface with the internal surface of the fitting is minimal and whose material is selected to cooperate with this minimal contact surface.

[0027] The fitting of the invention and its contextualization of operation in the coupling device are described first with reference to figures 1 to 3.

[0028] With reference to [Fig.1], the male fitting 1 comprises a longitudinal body 2 which extends from a junction end to a conduit 3 (the conduit is not shown) to a coupling end 4 to a second cooperating female fitting 1' of the coupling device 10 (Figures 2 and 3), which coupling end 4 has a fluid passage orifice 5 in fluidic communication with a flow channel 6 provided in the longitudinal body 2 and which extends inside the longitudinal body 2 from the coupling end 4 to the junction end 3.

[0029] The male fitting 1 further comprises a valve 7 which is disposed in the flow channel 6 of the longitudinal body 2 on the coupling end side. The main axis XX' of the valve 7 extends along the main axis XX' of the longitudinal body 2. The valve 7 comprises a valve head 8 which is located at the passage orifice 5 of the coupling end 4 of the longitudinal body 2. The valve head 8 extends longitudinally between a free end 11 and a junction base 15 with a longitudinal stem 17, which stem 17 extends in a tubular guide 18 of the fitting 1 forming a longitudinal guide means for the stem 17 in the fitting 1.

[0030] The valve head 8 is movable longitudinally within the fitting 1, and more particularly within the flow channel 6, towards its position of closing the passage orifice 5, by the application of a force F on said valve head 8 by means of actuation 9, here a helical spring surrounding the tubular guide 18 and extending longitudinally to the junction base 15 of the valve head 8. When no external force is applied to the valve head 8, the spring 9 at rest exerts a force Flm against the base 15 of the valve head 8, driving the valve head 8 into the passage orifice 5 in a sealed position in which the passage orifice 5 is closed by a sealed contact between the valve head 8 and a frustoconical valve head seat 10 formed in the longitudinal body 2 and in the internal extension of the passage orifice 5.In this position, the free end 11 of the valve head 8 extends into the passage orifice 5, protruding from the coupling end 4.

[0031] The valve 8 is also movable longitudinally in the fitting 1, and more particularly in the flow channel 6, towards a clear position ([Fig.3]) by the action of a force Fl exerted from outside the fitting 1 on the free end 11 of the valve head 8 which causes the spring 9 to compress and the opening of the fluid passage orifice 5.

[0032] With reference to Figures 2 and 3, the fluid line coupling device 20 comprises the male fitting 1 described above, and a second female fitting 1' which has a longitudinal body 2' extending from a junction end to a second line 3' (the second line is not shown) to a coupling end 4' which surrounds the coupling end 4 of the male fitting 1 by having a recess for the coupling end 4 having a bottom 19' opposite the coupling end 4 of the male fitting 1. As with the male fitting 1, the coupling end 4' has a liquid passage orifice 5' in fluidic communication with a flow channel 6' formed in the longitudinal body 2' and which extends from the coupling end 4' to the junction end 3'.

[0033] The female fitting 1' includes a valve 7' which is disposed in the flow channel 6' of the longitudinal body 2' and which includes a valve head 8' located at the passage orifice 5' of the coupling end 4' of the longitudinal body 2', and which is movable longitudinally in the flow channel 6' between a clear position in which the passage orifice 5' is open, and a closed, watertight grip position in which the passage orifice 5' is closed by watertight contact between the valve head 8' and the frustoconical valve head seat 10' via a sealing gasket 18'.

[0034] As with the first fitting 1, the valve head 8' of the female fitting 1' is movable longitudinally within the fitting 1', and more particularly within the flow channel 6', towards its position of closing the passage orifice 5', by applying a force F' to said valve head 8' by means of actuation 9', here a helical spring surrounding the valve stem 7' and extending longitudinally to the valve head 8'. When no external force is applied to the valve head 8', the spring 9' at rest exerts a force F' against the base 15' of the valve 8', driving the valve head 8' into the passage orifice 5' in a sealed position in which the passage orifice 5' is closed. In this position, the free end 11' of the valve head 8' extends into the passage orifice 5' by protruding from the coupling end 4'.

[0035] The valve head 8' is also movable longitudinally in the fitting 1', and more particularly in the flow channel 6', towards a clear position ([Fig.3]) by the action of a force Fl' exerted from outside the fitting 1' on the free end 11' of the valve head 8' which causes the spring 9' to compress and the opening of the fluid passage orifice 5'.

[0036] In operation, the respective valve heads 8,8' of the valves 7,7' of the male 1 and female 1' fittings are in longitudinal contact support and are alternately subjected to a concomitant position of clearance of the fluid passage orifices 5,5' of the first 1 and second 1' fittings ([Fig.3]), and to a concomitant position of closure of the fluid passage orifices 5,5' of the first 1 and second 1' fittings ([Fig.2]).

[0037] The transition from the concomitant position of release to the concomitant position of closure involves not only the springs 9,9' of the respective fittings 1,1', but also the relative position of the respective coupling ends 4,4' of the first 1 and second 1' fittings.

[0038] More specifically, in the concomitant position of blocking the fluid passage orifices 5,5' of the male 1 and female 1' fittings ([Fig.2]), the bottom 19' of the housing recess of the coupling end 4' of the female 1' fitting is at a distance from the coupling end 4 of the male 1 fitting and the springs 9,9' at rest each exert an application force F,F' on the valve heads 8,8' respectively of the male 1 and female 1' fittings, which results in the fluid passage orifices 5,5' of the male 1 and female 1' fittings both being blocked.

[0039] In the concomitant position of clearing the fluid passage orifices 5,5' of the male 1 and female 1' fittings ([Fig.3]), the bottom 19' of the recess for housing the coupling end 4' of the female fitting 1' is attached to the coupling end 4 of the male fitting 1 so that each valve head 8,8' of the valves 7,7' of the male 1 and female 1' fittings exerts against the valve head 8',8 of the valve 7',7 of the other fitting a force Fl',Fl which drives the valve heads 8,8' into their cleared position, the corresponding fluid passage orifices 5,5' then being open and the flow channels 6,6' of the male 1 and female 1' fittings being put into fluid communication.

[0040] With reference to figures 4 and 5, the valve 7 of the invention is described according to the first variant as well as the associated fitting 1.

[0041] According to the invention, the unique sealing contact bearing surface between the valve head 8 and the valve head seat 10 when the valve head 8 is in its closed sealing grip position and the fluid passage orifice 5 is sealed is an annular perimeter edge 13.

[0042] To this end, the free end of the sealing flap 11 of the valve 8 extends towards the junction base 15 to a coaxial shoulder 12 which, together with the base 15, defines a coaxial collar 14 of thickness lo. The coaxial shoulder 12 extends transversely to the annular perimeter edge 13, which has a diameter greater than the diameter of the free end 11 so that contact between the flap 8 and the frustoconical seat 10 of the fitting 1 can only occur by means of the annular edge 13.

[0043] The term "perimetric edge" refers to a linear configuration of the contact area between the valve 8 and the seat 10, which is an essential feature of the invention. However, this linear configuration is physically manifested by a surface, particularly during the contact pressure exerted by the edge 13 against the frustoconical valve head seat 10 formed in the longitudinal body 2. Therefore, the term "contact surface" may be used throughout the rest of the description without deviating from the linear configuration of the edge 13.

[0044] The only difference between the two embodiments shown in Figures 4 and 5 and Figures 6 and 7 concerns the dimensions of the coaxial collar 14 configuration. In the first embodiment shown in Figures 4 and 5, the collar 14 has a first frustoconical portion 16i that extends longitudinally, widening from the annular edge 13 to a second cylindrical portion 162 that extends longitudinally to the junction base 15. According to this embodiment, the height of the first frustoconical portion 16i is substantially the same as the height of the second cylindrical portion 162. In the second embodiment shown in Figures 6 and 7, the collar 14a of the valve head 8a of the valve 7a also has a first frustoconical portion 16ia that extends longitudinally, widening from the annular edge 13 to a second cylindrical portion. 162a which extends longitudinally to base 15.According to this variant, the height of the first truncated conical part 16 ia is substantially less than the height of the second cylindrical part 162a.

[0045] In these two configurations, the base angle A of the first frustoconical part 16i, 16ia is less than the base angle B of the frustoconical valve head seat 10 provided in the longitudinal body 2 ([Fig.4]) so that the annular edge 13 remains the only sealing contact area between the valve head 8 and the valve head seat 10 when the valve head 8 is in its closed position in sealing grip.

[0046] According to the third embodiment of the invention, the coaxial collar 14b of the valve head 8b of the valve 7b has a single cylindrical part which extends from the shoulder 12, and thus from the annular edge 13, to the junction base 15.

[0047] The other references relating to the common constitution of the three variants are repeated identically for these three variants.

[0048] Furthermore, and in order to ensure the application of sufficient pressure to achieve the required seal and impart the properties described below, the perimeter edge 13, and preferably the entire valve assembly 7, 7a, 7b, is made of fluoropolymer, preferably polychlorotrifluoroethylene (PCTFE). PCTFE provides the following advantageous properties: • significant mechanical resistance (rigidity, tensile / compressive strength, creep resistance). • It retains its mechanical properties and dimensional characteristics at cryogenic temperatures thanks to its very low rate of thermal expansion. This allows it to be used for structural components subjected to relatively high stresses for a thermoplastic. • a near-zero moisture absorption capacity which reduces the risk of moisture infiltrating the material, which can solidify at cryogenic temperatures and thus weaken the material, • chemical stability against oxidizing / corrosive agents due to the absence of hydrogen atoms in its composition, • significant resistance to flammability, which is a considerable advantage for applications involving pressurized liquid oxygen, • very good machinability allowing for strict dimensional tolerances and surface finishes.

[0049] For this purpose, the valve 7, 7a, 7b can be made by machining and turning from a raw polychlorotrifluoroethylene bar. This polymer has a modulus of elasticity of approximately 1400 MPa, which allows, for a minimum surface area such as that configured by an annular edge, for sufficiently flattening the surface defects of the seat, generally made of metal and more particularly of stainless steel like the entire longitudinal body 2 of the fitting 1.

[0050] The essential criterion of the invention lies in the presence of an annular edge 13 as the sole contact surface between the valve 8,8a,8b and the seat 10 and which leads to defining a surface of the annular edge less than 12 mm2 thus giving it its linear geometry proper to an edge.

[0051] Instead of maximizing the contact area between the valve head 8 and the valve head seat 10 to avoid the risk of leaks, it was considered, on the contrary, that the focus should be on evaluating the pressure to be applied to the surface of the valve head seat to deform the surface irregularities until they are crushed, thus ensuring the required seal. Indeed, it is surface defects that can generate leakage paths, known as interface leaks, which are contrary to the required seal.

[0052] Continuing along these lines, to reduce interface leakage, it is therefore necessary to minimize surface asperities. The pressure applied by the valve on the valve head seat of the fitting must then be adapted to the material and the surface condition of that material to ensure the deformation and crushing of surface defects, resulting in a small contact area between the valve and the valve head seat.

[0053] Thus, the applied pressure Ps must be greater than or equal to the stress o required to deform the most significant surface irregularity of the part until it is flattened. [Math 1] Ps > <7 with <7 = Ee (Hooke's Law) Formula 1 Where E is the elastic modulus of the surface of the annular edge (or of the valve if it is made of a single material), and 8. The deformation, which can be expressed as follows [Math 2]: ~ _ AL Formula 2 £~ h Where AL is the deformation of the largest surface asperity, which can be defined as being equal to 2 times the larger surface roughness Rt of the two contacting surfaces (the valve and the seat), and lo is the thickness of the annular collar 14,14a, 14b

[0054] We can thus define that the surface pressure to be applied must comply with the following formula [Math 3]: ps >}? — Formula 3

[0055] In the fitting of the invention, the pressure exerted on the valve results from the preload force of the spring 9 on the valve in its closed position and is defined by the following formula [Math 4]: p _ Formula 4 rs - S Where S is the contact surface between the valve head and the valve head seat of the fitting, i.e., the surface of the annular edge, and Fim is the preload force of the spring 9 on the base 15 of the valve.

[0056] Given that the force Fim is applied to the base 15 of the valve head 8 while the seal is made on the surface of the annular edge 13, the normal force F'im on the surface of the annular edge 13 is evaluated by the following formula [Math 5]: F\m = F]wi*cos(^) Formula 5 Where [3 is the angle formed by the axis of application of the normal force F'im and the axis of application of the force Fim exerted longitudinally on the base 15 of the valve head 8.

[0057] The surface area S of the annular edge 13 can then be evaluated by the following formula [Math 6]: F'* Formula 6 ô - lQ 2RfE Where is the thickness of the coaxial collar in millimeters? F'im is the normal force on the surface of the annular perimeter edge 13 in Newtons resulting from the application of the force from the actuation means 9 applied to the base 15 of the valve head E is the modulus of elasticity of the material of the annular perimeter edge 13 in MPa, and Rt is the surface roughness of the valve head seat 10 of the fitting 1.1a.

[0058] This formula could be considered in another sense by seeking for example to establish the value of the force Fim to be provided by the spring on the base 15 of the valve head 8, 8a,8b knowing the surface S of the annular edge and the surface roughness Rt of the material constituting the seat of the fitting, or alternatively by seeking the surface condition (Rt) of the valve head seat knowing the force Fim provided by the spring on the base 15 of the valve head 8,8a,8b and the surface S of the annular edge.

[0059] According to the invention, it has been established to adapt to existing fitting bodies by modifying only the shape of the valve 7,7a,7b, and more specifically of the valve head 8,8a,8b, and by adapting the spring 9 for the application of the required pressure.

[0060] According to one embodiment, the valve 7, 7a, 7b is made of polychlorotrifluoroethylene with a modulus of elasticity between 1300 and 1500 MPa, the longitudinal body of the fitting is made of stainless steel with a roughness Rt of less than 4 µm, preferably less than or equal to 2 µm, the force F'im is between 25 and 45 Newtons, and the thickness of the coaxial flange is between 2 and 3 millimeters. Applying the formula established above, the surface area of ​​the annular edge 13 must therefore be less than 34 mm².

[0061] More specifically, when the force Flm of the spring 9 on the base 15 of the valve head 8,8a is 36 Newtons, the base angle A of the first frustoconical part 16i, 16ia of the valve head 8,8a is 74° (the normal force F' 1m is then 28.7 Newton), the surface roughness Rt of the valve head seat of the stainless steel fitting is 0.002 millimeters and the modulus of elasticity of the polychlorotrifluoroethylene valve 7,7a,7b is 1400 MPa, then the surface of the annular edge 13 is less than 12 mm2.

[0062] A surface area of ​​the annular edge 13 less than 10 mm2 will be used more preferably, for example 9.91 mm2 for an annular perimeter of 58.18 mm. Such a condition results in an annular surface with a length of 0.3 millimeters and a width of 0.2 millimeters;

[0063] Leakage rate tests were carried out on the valve thus defined (PCTFE, annular edge area of ​​9.91, normal force F' 1m of 28.7 Newtons) by varying the surface roughness of the valve head seat (or of the longitudinal body of the fitting if the latter is made of a single material). The results are presented in Table 1 below: Test number Rt (in pm) Leakage rate (in mbar.l / s at 1.45 Bar) 1 4.3 io- 2 4 io- 3 3.5 103 4 2 107 Table 1

[0064] It is observed that if tests 1 and 2 do not meet the limit criterion of 10 3 mbar.l / s, tests 3 and 4 do meet this limit criterion.

[0065] Considering formula 7 above to establish the surface roughness criterion Rt of the valve head seat to be applied, we obtain the following formula [Math 7]: » 1 F^1 Formula 7 -l02SJE

[0066] For the valve thus defined, an Rt of less than or equal to 2 µm is obtained, which, according to the results in the Table, corresponds to a leakage rate of 107 mbar.l / s, well below the limit criterion. This ensures a sufficiently large degradation margin to maintain the performance of the fitting throughout the part's service life. It will therefore be defined that the surface roughness should preferably be less than 3.5 µm.

[0067] Thus, without being bound by any theory, it is demonstrated that by seeking, contrary to the prior art, the crushing of the surface irregularities of the valve instead of maximizing the contact area between the valve and the valve head seat, the defined contact area is minimal in the form of an annular edge with a surface area of ​​less than 34 mm2, preferably less than 12 mm2 made of polychlorotrifluoroethylene.

[0068] The invention also relates to the device as a whole as previously described with reference to Figures 2 and 3 and comprising the male fitting as defined, as well as the cooperating female fitting.

[0069] The valve and the fitting resulting from the invention thus ensure high sealing performance throughout the life of the part, and manual opening made difficult by the small bearing surface which increases the pressure required for opening.

Claims

Demands

1. Valve (7,7a,7b) for connecting a fluid line coupling device, which extends along a main longitudinal axis (XX') and which has a valve head (8,8a,8b) surmounting a stem (17), characterized in that said valve head (8,8a,8b) has a free end (11) extending towards a junction base (15) with the stem (17) to a coaxial shoulder (12) which delimits with the base (15) a coaxial collar (14,14a,14b) and which extends to an annular perimeter edge (13) having a diameter greater than the diameter of said free end (11), and in that the annular perimeter edge (13) is made of fluorinated thermoplastic polymer.

2. Valve according to the preceding claim, characterized in that the coaxial shoulder (12) extends transversely to the longitudinal axis (XX') up to the annular perimeter edge (13).

3. Valve according to any one of claims 1 and 2, characterized in that the coaxial collar (14b) is cylindrical and extends longitudinally from the annular perimeter edge (13) to the junction base (15).

4. Valve according to any one of claims 1 and 2, characterized in that the coaxial collar (14,14a) has a first frustoconical part (16i,16ia) which extends longitudinally, widening from the annular perimeter edge (13) to a second cylindrical part (162,162a) which extends longitudinally to the junction base (15)

5. Valve according to any one of the preceding claims, characterized in that the fluorinated thermoplastic polymer is polychlorotrifluoroethylene.

6. Valve according to the preceding claim, characterized in that it is made of polychlorotrifluoroethylene.

7. Valve according to any one of the preceding claims, characterized in that the surface area of ​​the annular perimeter edge (13) is less than 12mm2.

8. Fitting intended to form the male part of a fluid line coupling device, and comprising: - a longitudinal body (2) extending from a junction end to a line (3) to an end of coupling (4) to a second cooperating fitting of the coupling device, which coupling end (4) has a fluid passage orifice (5) in fluidic communication with a flow channel (6) formed in the longitudinal body (2) and extending from the coupling end (4) to the junction end (3), a valve (7, 7a, 7b) according to any one of claims 1 to 7, disposed in the flow channel (6) of the longitudinal body (2), the principal axis of which extends along the principal axis (XX') of the longitudinal body (2) of the fitting (1), and which comprises a valve head (8, 8a, 8b) surmounting a stem (17), which valve head (8, 8a, 8b) is located at the passage orifice (5) of the coupling end (4) of the longitudinal body (2), extending longitudinally between a free end (11) and a junction base (15) with the longitudinal rod (17),and is longitudinally movable within the flow channel (6) by applying a force (F) to said valve head (8, 8a, 8b) by means of actuation (9) between a clear position in which the passage orifice (5) is open, and a closed, sealed position in which the passage orifice (5) is sealed by a seal between the valve head (8, 8a, 8b) and a frustoconical valve head seat (10) formed in the longitudinal body (2) and in the internal extension of the passage orifice (5), the free sealing end (11) of the valve (1) extending into the passage orifice (5) by projecting from the coupling end (4), characterized in that the free sealing end (11) of the valve head (8, 8a, 8b) extends towards the junction base (15) up to a coaxial shoulder (12) which delimits with the base (15) a coaxial collar (14,14a,14b) and which extends to an annular perimeter edge (13) having a diameter greater than the diameter of said free end (11), which annular perimeter edge (13) constitutes the sole sealing contact bearing surface between the valve head (8, 8a, 8b) and the valve head seat (10) when the valve head (8, 8a, 8b) is in its, watertight gripping position, and in that the annular perimeter edge (13) is made of fluorinated thermoplastic polymer.

9. Fitting according to the preceding claim, characterized in that the coaxial shoulder (12) of the valve head (8,8a,8b) of the valve (7,7a,7b) extends transversely to the longitudinal axis (XX') up to the annular perimeter edge (13).

10. Fitting according to any one of claims 8 and 9, characterized in that the coaxial collar (14b) of the valve head (8,8a,8b) of the valve (7,7a,7b) is cylindrical and extends longitudinally from the annular perimeter edge (13) to the junction base (15).

11. Fitting according to any one of claims 8 and 9, characterized in that the coaxial collar (14,14a) of the valve head (8,8a,8b) of the valve (7,7a,7b) has a first frustoconical part (16i,16ia) which extends longitudinally and widens from the annular perimeter edge (13) to a second cylindrical part (162,162a) which extends longitudinally to the junction base (15)

12. Fitting according to the preceding claim, characterized in that the base angle (A) of the first frustoconical part (16X, 16ia) is less than the base angle (B) of the valve head seat (10) so that the annular edge (13) remains the only sealing contact bearing surface between the valve head (8,8a) and the valve head seat (10) when the valve head (8,8a) is in its sealing grip position.

13. Fitting according to any one of claims 8 to 12, characterized in that the fluorinated thermoplastic polymer is polychlorotrifluoroethylene.

14. Fitting according to the preceding claim, characterized in that the valve (7,7a,7b) is made of polychlorotrifluoroethylene.

15. Fitting according to any one of the preceding claims, characterized in that the valve head seat (10) is made of stainless steel.

16. Fitting according to the preceding claim, characterized in that the longitudinal body (2) of said fitting (1) is made of stainless steel.

17. Fitting according to any one of claims 8 to 16, characterized in that the surface (S) of the annular edge (13) is defined according to the following formula: Ff ô - £0 2RPE Or lo is the thickness of the coaxial collar (14,14a) in millimeters, F'im is the normal force on the surface of the annular perimeter edge (13) in Newtons resulting from the application of the force of the actuation means (9) applied on the base (15) of the valve head (8,8a,8b) E is the modulus of elasticity of the material constituting the annular perimeter edge (13) in MPa, and Rt is the surface roughness of the valve head seat (10) of the body (2) of the fitting (1).

18. Fitting according to the preceding claim, characterized in that the valve (7,7a,7b) is made of polychlorotrifluoroethylene with a modulus of elasticity between 1300 and 1500 MPa, the longitudinal body (2) of the fitting (1) is made of stainless steel with a roughness Rt of less than 4 pm, preferably less than or equal to 2 pm, the force F'im is between 25 and 45 Newtons, the thickness of the coaxial collar is between 2 and 3 millimeters and the surface of the annular edge (13) is less than 34 mm2.

19. Fitting according to the preceding claim, characterized in that the surface of the annular edge (13) is less than 12 mm2 and in that the roughness Rt of the valve head seat (10) is less than or equal to 2 pm.

20. Fitting according to any one of claims 8 to 19, characterized in that the means for actuation (9) of the movement of the valve head (9) comprise a spring (9) which extends to the base (15) of the collar (14) of the valve head (8,8a,8b) and which forces the valve head (8,8a,8b) towards its sealing position by the application of a force parallel to the longitudinal axis (XX') of the fitting (1) and the valve (7).

21. Fluid conduit coupling device, characterized in that it comprises a first fitting according to any one of claims 8 to 20 forming a male part and a second cooperating fitting (1') forming a female part, the second fitting comprising: - a longitudinal body (2') extending from a junction end (3') to a second conduit (3') to a coupling end (4') surrounding the coupling end (4) of the first fitting (1), which end of coupling (4') has a fluid passage orifice (5') in fluidic communication with a flow channel (6') formed in the longitudinal body (2') and which extends from the coupling end (4') to the junction end (3'), - a valve (7') disposed in the flow channel (6') of the longitudinal body (2') and comprising a valve head (8') located at the passage orifice (5') of the coupling end (4') of the longitudinal body (2'), and which is movable longitudinally in the flow channel (6') by actuation means (9') between a clear position in which the passage orifice (5') is open, and a sealed position in which the passage orifice (5') is closed by a sealed contact between the valve head (8') and a truncated conical valve head seat (10') provided in the longitudinal body (2') and in the extension of the passage orifice (5'), and in that the respective valve heads (8,8a,8b; 8') of the first and second fittings (1,1') are in longitudinal contact and subjected alternately, by the actuation means (9) associated with the valve head (8,8a,8b) of the first fitting (1) and the actuation means (9') associated with the valve head (8') of the second fitting (1'), in cooperation with the relative position of the respective coupling ends (4,4') of the first (1) and second (1') fittings, to a concomitant position of clearance of the fluid passage orifices (5,5') of the first (1) and second (1') fittings, and to a concomitant position of closure of the fluid passage orifices (5,5') of the first (1) and second (1') fittings.