EP3980350A1

EP3980350A1 - Valve for pressurised container

Info

Publication number: EP3980350A1
Application number: EP20743677.5A
Authority: EP
Inventors: Hervé BODET; Eric Gaillard
Original assignee: Lindal France SAS
Current assignee: Lindal France SAS
Priority date: 2019-07-29
Filing date: 2020-07-20
Publication date: 2022-04-13
Anticipated expiration: 2040-07-20
Also published as: US11787619B2; BR112022001611A2; CA3143113A1; EP3980350C0; WO2021018656A1; AR119459A1; EP3980350B1; US20220297925A1; MX2022001171A; CA3143113C; FR3099470A1; FR3099470B1

Abstract

The invention concerns a valve (1) comprising - a valve body (10) that has a cavity and that bears against a seal (40) provided with a central opening, and - a seat (20) that is able to move in the cavity, the seat bearing against the seal in the closed position and being spaced apart from the seal in the open position. The seat has a cavity that bears against the seal in the closed position, and is spaced apart from the seal in the open position. A rod (60) is attached in a non-detachable manner in the cavity, forming a seat/rod assembly, the rod being traversed, in its portion situated inside the cavity, by windows (612) opening in the outlet channel, the free end of the rod protruding out of the cavity and passing through the central opening of the seal.

Description

Pressure vessel valve

The invention relates to a valve for a pressure vessel, such as an aerosol generator, which valve comprises a valve body which has a cavity and which bears tightly by a first end against a seal provided with a central opening. , a seat which is placed movable in translation in the cavity of the valve body and which is pushed against the seal by return means, the seat being in sealed bearing against the seal in the closed position of the valve and being spaced from the seal by movement in the cavity of the valve body against the effect of the force of the return means in the open position of the valve, the seat having a cavity delimited by a sealing ridge, which sealing ridge bears tightly against the seal in the closed position of the valve, and is moved away from the seal in the open position of the valve.

Pressure vessels generally consist of a housing closed by a valve mounted on a cup. The product can be contained directly in the housing with the propellant gas. It can also be contained in a pocket to be separated from this propellant gas.

The valves include at least one sampling path that the product must pass through to exit the container. When the valve is closed, this sampling path is closed by a seal which divides it into an upstream part in contact with the interior of the container and a downstream part in contact with the outside.

The valves generally consist of a valve body having an interior cavity in direct fluid connection with the interior of the container or of the bag, or indirectly via, for example, a metering reservoir. The cavity belongs to the upstream part of the sampling path. The cavity is closed at its top by the seal making it possible to close the sampling path. A movable element is placed inside the cavity. It can move between a closed position of rest, in which the product cannot leave the container under pressure, and an open position in which the product can exit the container. In the closed position, the movable element cooperates with the seal to close the sampling path. A spring placed in the cavity tends to maintain the movable element in the closed position. This mobile element is a stem in the case of a male valve or a seat in the case of a female valve. In the case of male valves, the stem (also known as the stem or nozzle) is formed by a tubular duct open at its top and closed at the other end. One or more radial orifices are made in the tubular wall, in a radial plane located near the closed end. The closed end of the stem is placed in the cavity of the valve body, while the free end protrudes out of the valve, to be actuated by a diffuser fitted above. The interior of the tubular duct belongs to the downstream part of the sampling path. In the closed position, the orifices are aligned with the gasket placed at the top of the valve body cavity. The seal therefore blocks all the openings. The interior of the valve body is then isolated from the exterior by the seal. When pressure is exerted on the diffuser, it moves the stem downwards. The orifices move out of alignment with the seal and descend into the cavity. The product contained in the container can therefore pass into the cavity of the valve body, pass through the orifices thus released, continue in the tubular duct to leave the valve and enter the diffuser before being dispensed.

In the case of female valves, the movable element is a seat which rests on the seal annularly around a central opening of the seal. To open the valve, a tubular actuator rod must be inserted into the central opening of the seal. This actuating rod presses on the seat and pushes it down. The seat is thus moved away from the seal and an annular passage forms between the top of the seat and the seal, which passage contacts the interior of the valve body cavity with the exterior via the actuator rod.

Male valves and female valves each have their advantages. In both cases, it is possible to fill the case or the bag by passing through the valve. However, filling via the female valves is easier and faster, because the annular passage between the top of the seat and the seal has a much larger section than the few orifices made in the wall of the stem of the male valves and whose diameter is limited by the thickness of the seal and the stroke of the stem between the open position and the closed position.

Moreover, during actuation, the opening of a male valve is progressive, while the opening of a female valve is almost instantaneous. This is due to the fact that the orifices of the stem gradually disengage from the seal as the stem is pushed in. On the contrary, in the case of female valves, the seat is directly detached, immediately forming an annular passage. Likewise, when the pressure on the movable element is removed, the female valve closes suddenly, while the male valve closes slowly. The product therefore continues to flow momentarily while the user has stopped actuating the valve. Despite this apparent superiority of female valves over male valves, many users prefer male valves, especially since it is easier, when assembling the packaged product, to center the diffuser on the male valve due to the portion of the valve. stem protruding above the male valve. The objective of the invention is therefore to combine the advantages of male valves and those of female valves.

This is achieved with a valve according to the preamble, in which a stem (also known as a stem or nozzle) is non-detachably attached in the seat cavity forming an integral seat / stem assembly. , which stem is composed of a tubular wall which surrounds an outlet channel open towards the end opposite the seat, and which is crossed in its part located inside the cavity by one or more passage windows, the part of the stem opposite to the seat and located beyond the passage windows projecting out of the seat cavity passing through the central opening of the seal.

It is preferable

- that the seat comprises a tubular wall, a first end of which forms the sealing ridge, said tubular wall being completely closed at a distance from the sealing ridge by a transverse wall, thus forming the seat cavity

- that the lower part of the tubular wall of the stem is dimensioned to penetrate into the tubular wall of the seat, and

- that an annular recess extending around the tubular wall of the stem is formed in the upper part of the tubular wall of the seat which is located opposite the passage windows of the stem, the annular recess extending to the sealing edge. This annular recess radially extends the seat cavity.

It is preferable that the windows do not encroach on the seal. For this, it is preferable that the ends of the passage windows directed towards the seal are flush with the face of the seal directed towards the seat cavity and / or that said ends are located at a distance from said face of the seal. Concretely, the windows can extend when the valve is in the closed position either up to the seal, or stop below and away from the seal. When the valve is open the windows are moved downwards and in any case are away from the seal. It would of course be possible that in the closed position of the valve, the upper part of the windows penetrates over part of the height of the seal. The stem can be attached to the seat by any suitable means. Welding is a particularly well suited method of attachment, in particular ultrasonic welding or rotational welding. A reserve of material can be provided for welding on the seat and / or on the stem.

The return means are preferably constituted by a spring. In order to stabilize the spring, it is preferable to provide the seat, opposite its sealing edge, with a centering pin around which one end of the spring fits.

To facilitate the fixing of the stem in the seat cavity, a fixing stud can be placed in the seat cavity, on the transverse wall, the stem being fixed to the seat on the fixing stud, preferably on a front face of that -this.

In a particular embodiment of the invention,

- the tubular wall of the stem is open at both ends, a transverse wall being placed inside the tubular wall, between the passage windows and the end of the stem placed in the seat cavity, and at a distance from said end, a preferably through opening being made in the face of the transverse wall directed towards the end located in the cavity,

- a centering projection is produced on the seat fixing pin, preferably on its front face,

- the tubular wall of the stem, in its part located in the seat cavity, being dimensioned so that the fixing stud penetrates inside through the end, and the centering projection being dimensioned to penetrate into the opening made in the transverse wall .

The seal can be locked against the upper edge of the valve body by a cup provided with an opening for the free end of the stem, the cup being able to be crimped onto an annular crown of the valve body.

The valve body can be fitted

- an attachment tenon to attach a dip tube or anti-sagging means; and or

- a fastening wall for attaching a pocket, said fastening wall surrounding the fastening pin when there is one.

One or more longitudinal grooves can be made in the cavity of the valve body so that the product can more easily bypass the seat. The longitudinal groove or grooves preferably extend from the annular passage to at least the lowest position taken, when the valve is in the open position, through the end of the seat opposite the sealing ridge. The invention is described in more detail with the aid of an exemplary embodiment presented in the figures which show:

[Fig. 1]: an exploded view of a valve according to the invention;

[Fig. 2]: a sectional view of the valve of FIG. 1 (a) before and (b) after assembly of the stem;

[Fig. 3]: a view of the valve body (a) in perspective from below, (b) in perspective from above, (c) from above, (d) from below and (e) in section in perspective;

[Fig. 4]: a view of the seat (a) in perspective from above, (b) in perspective from the bottom and (c) in section in perspective;

[Fig. 5]: A perspective sectional view of the joint;

[Fig. 6]: A view of the stem (a) in perspective and (b) in section in perspective;

[Fig. 7]: A sectional view of the seat / stem assembly;

[Fig. 8]: A perspective sectional view of the valve of the invention;

[Fig. 9]: a sectional view of the valve (a) in the closed position and (b) in the open position.

[Fig. 10]: An enlarged section of the inside of the valve (a) in the closed position and (b) in the open position.

The invention relates to a valve (1), in particular a pocket valve, intended to close the housing of a pressure vessel.

Conventionally, the valve is shown with the stem at the top, without this being limiting. The references "top" / "bottom" or "upper" / "lower" have only a relative value in relation to the representations of the attached figures. It goes without saying that in some cases the valve can be used in other positions and what is up in the position shown here will not necessarily be in use. Furthermore, the valve in the assembled state extends along a main axis (A), vertical in the representations of the attached figures. The terms “radial”, “axial” and “transverse” refer to this main axis (A). The valve (1) shown here has all the attributes of a female valve. It mainly consists of a valve body (10) having a cavity (11) in which a seat (20) and a spring (30) are placed. The upper opening of the cavity (11) is closed by a seal (40). The cavity is in direct or indirect fluidic connection with the interior of the container. A cup (50) can be crimped onto the valve body (10) by blocking the seal (40). Unlike a female valve, the valve of the invention is also provided with a stem (60). If necessary, a pocket (70) can be welded to the valve body (10). The valve body (10) consists of a tubular wall (12) open at both ends which extends, in the assembled state of the valve, around the main axis (A). The interior of the tubular wall defines the cavity (11) of the valve body. The tubular wall preferably has substantially the shape of a cylinder of revolution. Its more tapered upper end forms an upper ridge (121) which extends in a radial plane. Three grooves (122) are made in the inner face of the tubular wall. They extend in the longitudinal direction of the tubular wall, therefore in a substantially vertical manner in the present case. The grooves (122) extend from the tapered shape of the upper end (121) to at least the lowest position taken, when the valve is in the open position, by the lower end of the seat. The outer face of the tubular wall has at the upper end an annular ring (123) in the form of an extra thickness of material to allow the crimping of the cup (50) on the valve body. An attachment lug (13) for attaching an anti-sag device or a dip tube is attached, for example by four bridges (131), to the lower end of the tubular wall (12). These four bridges (131) also fulfill the function of stopper for the spring (30). It would be possible not to provide an attachment tenon (13), in which case it would be preferable to provide a stop inside the tubular wall to support the spring.

In order to be able to fix a pocket on the valve, a fixing wall (14) is made on the tubular wall (12), below and at a distance from the annular crimping ring (123). This fixing wall surrounds the lower end of the tubular wall (12) and the fixing pin (13). It preferably has a flattened diamond-shaped cross section with the angles of the small diagonals obtuse and rounded, and the angles of the large diagonals acute and more pointed, as can be seen in Figure 3d. This shape facilitates the welding of the pocket (70). If the valve is to be used without a pocket, this fixing wall (14) can be dispensed with. The seat (20) of the invention consists of a cup-shaped element having a cavity (21) delimited by a tubular wall (22) and a transverse wall (23) which is preferably continuous radially. The tubular wall (22), when the seat is mounted in the valve, extends around the main axis (A). It preferably has substantially the shape of a cylinder of revolution. It is open at one of its ends forming a sealing ridge (221) extending in a radial plane. The seat (20) is dimensioned to be able to fully penetrate the cavity (11) of the valve body while being able to slide freely therein. Concretely, the tubular wall (22) of the seat can slide parallel to the main axis (A) in the tubular wall (12) of the valve body. The tubular wall (21) of the cavity has an upper portion (222) of larger diameter which extends to the sealing ridge and which forms an annular recess (211) around the cavity itself in extending it radially. The radial wall (23) closes the tubular wall (22), preferably at the end opposite the sealing edge (221), so that the cavity (21) is only accessible through the defined opening by the sealing edge (221). The lower face of the radial wall (23) is extended by a centering pin (24) to center the spring (30). In order to save material and to facilitate the handling of the seat during assembly, the centering pin (24) is not solid, but made up of two segments of a tubular wall. The slot (241) which delimits the two tubular segments extends in part into the underside of the radial wall (23). A fixing stud (25) is produced on the upper face of the radial wall (23). It is preferably substantially in the form of a solid cylinder concentric with the tubular wall (22) of the seat. The front face (251) of the fixing stud, opposite the radial wall, is preferably frustoconical with the top of the cone located at the bottom. The upper edge of the front face constitutes an annular reserve of material (252) for welding the stem. It is preferable to place in the center of the front face of the fixing pin a centering projection (253) which is preferably rounded at its top.

The geometry of the seat, and in particular its external size, must take into account that a sliding movement inside the valve body from top to bottom must be able to allow the valve to open. Conversely, a sliding movement of the seat from the bottom to the top must be done easily inside the valve body to guarantee the rapid closing of the passage windows (612) by the seal (40) and the closing of the valve. to control product distribution.

The stem (60) consists of a tubular wall (61) which, in the assembled state of the valve, extends around the main axis (A). This tubular wall (61) is open at both ends and defines an outlet channel (62). The lower end (611) of the tubular wall is dimensioned to be able to penetrate into the cavity (21) of the seat. It is preferably tapered to facilitate its centering during its introduction into the cavity (21) of the seat. Above and at a distance from this lower end, a wall has been placed inside the outlet channel (62). transverse (63), preferably radial, so as to reduce its cross section, or even to block it. An orifice (631) at least open downwards can be made in the radial wall. In the present example, the orifice (631) is through. Large passage windows (612) are made in the tubular wall, above the radial wall (23). In the example shown here, there are four windows aligned two by two. These windows extend in the same radial plane, without necessarily being radial themselves.

The internal dimensions of the tubular wall (61), at least in its lower part (613) located between the radial wall (63) and the lower end (611), are such that the fixing stud (25) can enter it. without restraint. Likewise, the orifice (631) of the radial wall of the stem is dimensioned so that the centering projection (253) of the seat can enter it without constraint.

The seal (40) has a generally annular shape. The inside diameter of its central opening (41) is chosen so that it tightly encloses the tubular wall (61) of the stem while allowing it to slide when the valve is actuated. The outer diameter of the seal is greater than the diameter of the upper ridge (121) of the valve body. In the assembled position of the valve, the upper ridge (121) rests tightly against the seal (40).

The spring (30) fulfills the function of return means, making it possible to bring the seat back into abutment against the seal to close the valve.

According to the invention, the seat (20) and the stem (60) are attached to each other to form a seat / stem assembly (80). For this, the stem is introduced with its lower end (611) into the cavity (21) of the seat until its radial wall (63) comes into contact with the upper part of the frustoconical face (251) of the stud. fixing forming a reserve of material. In this position, the centering projection (253) penetrates the opening (631) made in the radial wall (63) of the stem and the lower part (613) of the tubular wall of the stem partially surrounds the fixing stud ( 25) of the seat. The welding is done at this reserve of material (252). Welding can be done in different ways, in particular by ultrasound or by spin welding. As shown in Figure 7, the large passage windows (612) of the stem open into the annular recess (211) of the seat cavity. The top of the passage windows (612) is in the radial plane defined by the sealing edge (221) of the seat, or slightly below. This also means that, in the assembled state of the valve, the top of the passage windows (612) is flush with the seal (40) or is located slightly below. In the open position of the valve, the windows are anyway away from the joint. It would also be possible for the top of the windows to be located inside the seal, without however going over it.

The section of the outlet channel (62) and the section of the passage windows (612) are calculated so as not to create a flow restriction corresponding to the flow around the seat. In particular, the total cross section of the windows (612) and that of the outlet channel (62) are preferably of the same order of magnitude, or even greater, than the narrowest cross section in the outlet passage (122, 211) upstream of the windows. Furthermore, since the stem must be able to withstand a vertical compressive force allowing the valve to open, it is preferable to dimension the thickness of its wall to allow this force, without limiting the section of the passage windows. A compromise must therefore be found to optimize the wall thickness and the vertical compressive strength of the stem while allowing clearance between the external diameter of the stem and the central opening of the cup through which it passes. The outer diameter of the stem in its upper part located outside the valve body and above the horizontal plane formed by the central opening, or at least above the rounded upper part of the cup must allow the fixing of a means of distribution. In its lower part, the outer diameter of the stem should allow its introduction inside the seat.

It is not currently known how to mold such a seat / stem assembly (80) due in particular to the presence of the passage windows (612) oriented radially and hidden behind the upper part (222) of the tubular wall of the seat. It is therefore necessary to manufacture these two parts separately and then to assemble them.

Depending on requirements, it is possible in a preliminary step to attach an anti-collapse device or a dip tube to the attachment pin (13) and / or to fix a pocket (70) on the outside face. of the fixing wall (14) before folding or rolling it around the main axis (A).

The valve is assembled as follows. The spring (30) is introduced into the cavity (11) of the valve body (10) until its lower end rests on the fixing bridges (131) of the tenon (13). The seat (20) is then introduced so that its centering pin (24) penetrates inside the spring (30) and that its cavity is open upwards. The spring is thus sandwiched between the fixing bridges (131) of the valve body at the bottom and the underside of the radial wall (23) of the seat at the top. The seal (40) is then placed at the top of the valve body (10), the upper edge (121) thereof resting on the seal. The cup (50) is then placed on and around the annular crown (123) of the valve body with its central opening centered on the main axis (A) and on the central opening (41) of the seal. The cup is then crimped, resting under the annular crown (123) of the valve body. The stem (60) is then introduced by its lower end (61 1) into the cavity (21) of the seat, passing through the central opening of the cup and the central opening (41) of the seal. The stem is then welded to the seat, for example by ultrasound. It would also be possible to make the seat / stem assembly (80) first before assembling the valve. When the stem is welded after assembly of the valve, it must be taken into account that the welding requires the application of a downward vertical force to maintain sufficient contact between the weld zone of the stem and the supply of material supplied by the seat fixing tooth. It is therefore preferable to size the spring (30) so that it exerts a back pressure greater than that applied during the welding so as not to allow the seat / stem system to be driven into the valve body during the joining of the two components.

The grooves (122) extend from the tapered portion of the upper end of the valve body to below the underside of the radial wall (23) of the seat when it is pulled away from the seal in the open position of the valve . The grooves do not go all the way to the top ridge (121) as can be seen in Figure 10, in order to avoid sealing problems.

At all times, the upper ridge (121) of the valve body is sealingly resting on the seal (40). In the closed rest position of the valve, the sealing ridge (221) of the seat also bears tight against the seal, the seat being pushed back by the spring. As in a traditional male valve, the stem passes through a central opening of the cup and protrudes outside the valve, and as in a female valve, the sealing is done, when the valve is in the closed rest position. , at the sealing edge (221) of the seat in sealed contact with the underside of the seal (40).

The valve of the invention operates as follows. Pressure is exerted on the upper end of the stem (60) of the seat / stem assembly (80) using a diffuser for a male valve fitted onto the protruding part of the stem. The seat / stem assembly (80) is moved downwards against the effect of the spring (30). The sealing edge (221) of the seat is then moved away from the seal and an annular passage (26) is formed between the sealing edge (221) of the seat and the underside of the seal, as can be clearly seen on Figure 10. Under the effect of the pressure difference between the pressure inside the pressure vessel and atmospheric pressure, the product contained inside the vessel enters the bottom of the cavity (11) of the valve body, bypassing the fixing bridges (131) and / or by a dip tube attached to the fastening pin (13). It then rises in the cavity (1 1) of the valve body, passing the along the spring (30), bypasses the tubular wall (22) of the seat by passing through the grooves (122), passes through the annular passage (26), enters the annular recess (211) of the seat cavity, traverses the passage windows (612) and enters the outlet channel (62).

As soon as the pressure exerted on the stem is released, the spring (30) pushes the seat / stem assembly (80) upwards until the sealing edge (221) of the seat is again in contact tight against the underside of the seal (40). The product output channel is interrupted at this interface.

The valve of the invention differs from a traditional male valve by the fact that the passage windows (612) of the stem always remain open and do not need to be closed by the seal. Whatever the position of the valve, the passage windows bring into contact the exterior of the valve and the cavity (21) of the seat via the outlet channel (62) of the stem. Passage windows are always located below the seal. Their dimensions are therefore not imposed by the thickness of this seal unlike the passage openings of a traditional stem. It is therefore possible to provide much larger passage windows, and in particular higher. Simply adjust the height of the annular recess (211) in the seat cavity to the desired height of the windows (612). With the valve of the invention, the rate of filling through the valve is much faster than with a traditional male valve and approaches that of a female valve. The valve of the invention is therefore particularly well suited to viscous products and / or rapid filling via the valve. The valve of the invention combines the advantages of female valves (quick opening and closing, large passage windows) and those of male valves (stem protruding from the valve for easier centering of the diffuser).

The valve of the invention is particularly intended for use as a pocket valve. However, it is possible to use it without a pocket. In the example shown here, the valve is of the traditional type with a metal cup crimped on it. The seat / stem assembly (80) can however be used in any other type of valve, and in particular in so-called “all plastic” valves where the cup is made of plastic and the valve body is snapped onto the cup or is an integral part. of it. The seat / stem assembly (80) can in particular be applied to valves of the type of those described in patent application WO 2016/202 754 A1 or FR 18 54 513.

The seat and the stem can be made, for example, of POM (polyoxymethylene) or of PA (polyamide). The material chosen must be compatible with the product to be dispensed. The body valve can be for example in POM or, if a bag has to be welded on, in PE (polyethylene) or in PP (polypropylene).

List of references

1 Valve

10 Valve body

11 Cavity

12 Tube wall

121 Upper edge

122 Grooves

123 Ring crown

13 Attachment post

131 Fixing bridges

14 Pocket fixing wall

20 Seat

21 Cavity

211 Annular recess

22 Tube wall

221 Sealing edge

222 Upper part

23 Radial wall

24 Centering pin

241 Slot

25 Fixing stud

251 Upper side

252 Material allowance

253 Centering projection

26 Annular passage

30 Spring

40 Seal

41 Central opening

50 Cup

60 Stem (or stem)

61 Tube wall

611 Lower end

612 Passage windows

613 Lower part

62 Output channel

63 Radial wall

631 Opening

70 pocket

80 Seat / stem assembly

Claims

1. Pressure vessel valve, comprising

- a valve body (10) which has a cavity (1 1) and which bears tightly by a first end (121) against

- a seal (40) provided with a central opening (41),

- a seat (20) placed movable in translation in the cavity (11) of the valve body and pushed against the seal (40) by

- return means (30),

the seat resting tightly against the seal in the closed position of the valve and being moved away from the seal by displacement in the cavity (1 1) of the valve body against the effect of the force of the return means in the open position of the valve ,

the seat having a cavity (21) delimited by a sealing edge (221), which sealing edge bears tightly against the seal (40) in the closed position of the valve, and is spaced from the seal (40) in forming an annular passage (26) in the open position of the valve characterized

- in that a rod (60) is fixed in a non-detachable manner in the cavity (21) of the seat forming a seat / rod assembly (80) in one piece, which rod (60) is composed of a tubular wall (61) which surrounds an outlet channel (62) and which is crossed in its part (613) located inside the cavity (21) by one or more passage windows (612) opening into the outlet, the free end of the rod (60) located beyond the passage windows (612) projecting out of the cavity (21) of the seat passing through the central opening (41) of the seal (40).

2. Valve according to claim 1, characterized

- in that the seat (20) comprises a tubular wall (22), a first end of which forms the sealing edge (221), said tubular wall being completely closed at a distance from the sealing edge by a transverse wall (23),

- in that the lower part (613) of the tubular wall of the rod is dimensioned to penetrate into the tubular wall (22) of the seat, and

- in that an annular recess (21 1) extending around the tubular wall (61) of the rod is formed in the upper part (222) of the tubular wall of the seat which is located opposite the passage windows (612) of the rod, the annular recess (211) extending to the sealing edge (221).

3. Valve according to claim 1 or 2, characterized in that in the closed position of the valve, the ends of the passage windows (612) directed towards the seal (40) are flush with the face of the seal (40) directed towards the cavity. (21) of the seat and / or said ends are located at a distance from said face of the seal.

4. Valve according to one of the preceding claims, characterized in that the rod (60) is fixed to the seat (20) by welding, preferably by ultrasonic welding or by rotation welding, a reserve of material (252) being able to be provided on the seat (20) and / or on the rod (60) for welding.

5. Valve according to one of the preceding claims, characterized in that the return means are constituted by a spring (30), and in that the seat has, opposite its sealing edge (221), a centering pin (24) around which takes place one of the ends of the spring (30).

6. Valve according to one of the preceding claims associated with claim 2, characterized in that a fixing stud (25) is placed in the cavity (21) of the seat, on the transverse wall (23), the rod ( 60) being fixed to the seat on the fixing stud, preferably on a front face (251) thereof.

7. Valve according to the preceding claim, characterized

- in that the tubular wall (61) of the rod is open at both ends, a transverse wall (63) being placed inside the tubular wall (61), between the passage windows (612) and the end (611) of the rod placed in the cavity (21) of the seat, and at a distance from said end (611), an opening (631) preferably through being made in the face of the transverse wall (63) directed towards the end (611),

- in that a centering projection (253) is produced on the fixing stud (25) of the seat, preferably on its front face (251),

- the tubular wall (61) of the rod being dimensioned so that the fixing stud (25) penetrates therein through the end (611), and the centering projection (253) being dimensioned to penetrate into the opening (631) carried out in the transverse wall.

8. Valve according to one of the preceding claims, characterized in that the seal (40) is blocked against the edge (121) of the valve body by a cup (50) provided with an opening for the free end of the rod (60).

9. Valve according to one of the preceding claims, characterized in that the valve body (10) is provided - an attachment tenon (13) for attaching a dip tube or anti-sagging means; and or

- a fixing wall (14) for fixing a pocket (70), said fixing wall surrounding the fastening pin (13) when there is one.

10. Valve according to one of the preceding claims, characterized in that one or more longitudinal grooves (122) are formed in the cavity (11) of the valve body, which longitudinal grooves (122) preferably extend from the annular passage (26) to at least the lowest position taken by the end of the seat opposite the sealing edge (221) when the valve is in the open position.