FR2602303A1 - "Double seal" valve for compressed and liquefied gas bottles - Google Patents

Abstract

The present invention relates to a tight-seal valve for compressed or liquefied gas bottles. This valve is characterised in that it comprises a sealing ring 21 surrounding the tail 3 of the body 2, this ring 21 having a threaded inner part 22 which is screwed onto a threading provided on a cylindrical part 23 of the body 2; the ring 21 has, in its lower front face, a transverse annular groove in which there is housed a toric gasket 24, and the ring 21 furthermore also has, in the upper part of its inner wall, a transverse annular groove in which there is housed another gasket 25 which is applied against a cylindrical part 26, having the same diameter, of the body 2.

Description

 The present invention relates to a high tightness tap for cylinders of compressed or liquefied gases.

 The significant development of the market for certain compressed or liquefied gases, which are toxic in themselves, leads to more frequent handling of the corresponding bottles and leads to the need to have liquids, and ensures tightness and safety in use. best possible. Actuellemert ori utlise, for cob to hold urie high tightness, taps either with membranes or with bellows to equip bottles containing toxic gases. These devices, namely set of metal membranes or metal bellows, allow to trar, smet- to the door - valve pushing a control rod. These devices ensure, for such a movement, better taring than the O-rings generally used for conventional taps. However, if these devices fail, a leak then occurs because a second seal is generally not expected. In addition, in the case of the use of a metallic bellows, gold, counts on the fixing of the bellows to ensure the tightness. Once again there is a risk of having a leak there again, in the long run, as a result of the fatigue of the bellows.

 The present invention aims to remedy these iricorivery, er, providing uni robirie t provided with means which guarantee, in a very simple manner, a very high tightness veriar t reri forcing that normally provided by members or the bellows.

To this end, this high-tightness tap for cylinders of compressed or liquefied gases, comprising a body having, at one end, a tail through which the body of the tap can be screwed into a thread provided in a plain flange of the bottle. conduit crossesarit axially the tail and opening, by ri coridiji t of smaller diameter delimited by ri valve seat, daris a room in which is housed ri valve and which communicates ri outlet outlet, and control means of the valve for the mairitenir pressed on or away from the seat, respectively in the closed and open positions of the tap, is characterized in that it comprises a united sealing ring surrounding the tail of the body, this ring having a united internal part threaded which is screwed on ri threading provided on a plain cylindrical part of the body is vanit hole above the tail, the ring has, danis its lower front face, an annular groove transv ersale in which is housed an O-ring seal which is thus applied to the upper surface of the flange, eri is compressed and crushed against this surface, to ensure a seal at this point, and moreover the ring also has t in the upper part of its internal wall, a plain annular trariversal groove in which is housed another seal which is applied against a plain cylindrical part; of the same diameter, of the body which is located above the cylindrical threaded part of the body
In addition, auxiliary toric seals are arranged behind the membranes or the bellows, to form a united second seal.

However, will describe below, by way of nonlimiting examples, various forms of execution, of the pre-invention, with reference to the attached drawing in which
Figure 1 is a view in axial section of a metal diaphragm valve mounted on a bottle containing a compressed or liquefied gas.

 Figure 2 is a plain view er, axial section of a united va riant execution of the valve comprising a bellows with a single hopscotch and pneumatic control device.

 The membrane valve represented in FIG. 1 is screwed onto the collar 1 of a single bottle containing the compressed or liquefied gas. This tap has a plain body 2 which ends at its lower part by a plain tapered shank 3 preritanit at its periphery, a conical thread being screwed into a conical thread 4 provided in the flange 1.

Tightness is ensured at the place of screwing of the tapered tail 3, thanks to the provision of a single garureure in coriniue material under the name of "Teflon".

 The body 2 of the tap is pierced axially, from side to side, with a uniform coriduit 5 which opens, at its lower end, into the lower front face of the stem 3 and at its upper end forming a single conduit of smaller delimited diameter by a single valve seat 7, in a single chamber 6 communicating with a single outlet orifice 10.On this seat 7 is applied a valve 8 carrying, on its front face, a plain pellet 9, made, for example, of a single material such as that coniniu under the r, om of "Célorori", this pellet 9 ensuring etarichity by being applied to the seat 7.The valve 8 crosses a plain guide ring 11 which is pierced with holes 12 so that the pressure of the gas coriteriu d anise the bottle corgtribue to the raising of the valve 8 from the start of the opening of the tap. The valve 8 tends to be lifted and consequently moved away from the seat 7 by a single spring 8a housed in the chamber 6. This spring 8a bears under a widened head 13 which is integral with the upper end of the valve S and against the face upper of which is supported by a pusher 14, with interposition in them of several transverse membranes 15 made of very stiff stainless steel. These membranes 15 which are intended to isolate the valve 8, from a waterproof barrier, from the outside , soni t mair, ter, ues er, support, by their marginal or peripheral parts, on an annular shoulder 16 of the body 2 and they are pressed on this shoulder by the annular lower front face of a guide nut 17 with thread exterior screwed with anise united suitable thread provided in the upper part of the body 2. Daris this guide nut 17 is screwed a control rod 18 which exerts a united push down on the pusher 14 and which is secured, at its upper end, to a steering wheel 19.

 In Figure 1 the valve is shown in the closed position. To open the gold valve, turn the handwheel 19 by one turn, which causes the control rod 18 to rise, along with the guide nut 17. The spring 8a then lifts the valve 8, eri acting under the head 13 if bier, that the valve 8 deviates from its seat 7, repels neither the nied limbs 15. These nied limbs are deformed neither t then according to the opening stroke caused by the control rod 18. The opening of the valve 8 results in a solid communication of the conduit 5 with the outlet orifice 10.

 According to the invention, in order to reinforce the seal, the valve t has a plain sealing ring 21 surrounding the upper part of the conical tail 3 of the body 2. This ring 21, of cylindrical shape, has a plain internal threaded part 22 which is screwed onto a thread provided on a plain cylindrical part 23 of the body 2 located above the tapered shank 3. The ring 21 has, in its lower front face, a transverse annular groove in which is housed united joining toric etherity 24 who live airisi apply on the upper surface of the collar 1, er; being compressed and crushed against this surface, to ensure a tight seal at this point.

 Furthermore, the ring 21 has, from the upper part of its internal wall, united annular groove trar, versa the dory which is housed with another seal 25 which is applied against a cylindrical part 26, of the same diameter, which is located between the cylindrical threaded portion 23 and the rest of the valve body 2. This cylindrical part 26 has joined a single diameter slightly greater than that of the threaded part 23 which has itself joined a single diameter slightly greater than that of the large base, that is to say of the upper end of the condic tail. 3.

 The tightness is also reinforced, in the valve following the invention, at the upper part of the body 2.

More particularly, this tightness is ensured, above the membranes 15, by means of a first first O-ring 26 which is housed in a transverse annular groove formed in the lower part of the lateral surface of the nut 17, united slightly above the shoulder 16 serving as a support for the membranes 15. However, as a variant, the gasket 26 could be housed in a transverse annular groove provided in the wall of the body 2 receives the lower part of the guide nut 17.

 Another O-ring seal 27 is provided between the upper parts of the guide nut 17 and of the control rod 18. This O-ring 27 can be housed, as shown in FIG. 1, in a trarisversale annular groove provided in the internal face of the guide nut 17, above its internal thread, or else in a groove formed in the control rod 18.

 In the variant embodiment of the invention shown in FIG. 2, the valve is provided, at its lower part, with the same seal ring 21 comprising the two O-rings 24 and 25. In this case, the valve comprises a bellows 31 which surrounds a solid push rod 32 for the valve 8 and which isolates the valve 8 from the outside. This valve 8 is fixed to the lower end of the rod 32.

Furthermore, the bellows 31 is fixed at its lower end to the valve 8 and, at its upper end, to a plain guide groove 33 which is crossed by the push rod 32. Uni Joirit O-ring seal 34 is interposed between the guide washer 33 and the push rod 32, being housed in a solid groove either in the washer 33 as shown in FIG. 2, or on the push rod 32. Furthermore, two other rings, annular sealing ts 33a and 33b are interposed between the guide washer 33 and the wall of the body in which it is housed.

 At its upper end the push rod 32 is integral with a axial control rod 35 feisenit protruding outside the robir, and. The rod of commar, of cross member uni piston 36 my, tee with sliding in uni cylinder 37 dorit the part iniférieura 37a, of smaller diameter, is provided with uni thread by which the cylinder 37 is screwed in the body 2 of the tap. This cylinder 37 is closed, at its upper end, by ur, nut 38 serving to the setting of a plain spring 39 which is compressed between nut 38 and the piston, 36.

The piston, 36 is doric biased year, permarierice down and it is kept pressed against the bottom of the cylinder 37. The control rod 35 is provided in its upper part with plain thread 41 by which it is screwed danis uni corresponding tarage formed in the upper part of the cylinder was cylindrical 42 extending upwards the piston 36. The upper upper part of the control rod 35 is integral with the flywheel 43, by means of the limiter of coupla 44.

 Furthermore, the valve shown in FIG. 2 is designed to allow pneumatic control. To this end, the control rod 35 is pierced axially with a single conduit 45 which opens into the upper front face of this rod 35, so as to be able to be connected to a solid source of pressurized fluid. This duct 45 communicates, at its lower part, with transverse ducts 46 which open into a space included below the piston 36.

 To improve the seal at the location of the control rod 35, two O-ring seals 47 and 48 are provided between this rod and the cylindrical wall in which it slides. The lower seal 47 is housed in a united transverse annular groove provided in the control rod 35 or in the inner wall of the small-diameter iniférieura part 37a of the cylinder 37 in which it slides. The upper seal 48 is housed in a transverse annular groove provided in the commaride rod 35 or in the wall of the piston 36 or of the barrel 42 pro lorigearit the latter upwards.

 It can be seen from the foregoing description that the joirits of toroidal etarichities 34, 47 and 48 contribute to rani notably forcing security with regard to any possible leak resulting from a rupture of the bellows 31.

Claims (3)

 1.- High tightness tap for cylinders of compressed or liquefied gas, with a single body (2) pre-tightness, with a single end, a single stem (3) by which the body of the tap can be screwed into a thread ( 4) provided with a plain flange (1) of the bottle, plain conduit (5) passing axially through the tail (3) and opening out, by plain conduit of smaller diameter delimited by a valve seat (7), in a plain chamber (6 ) in which is housed a single valve (8) and which communicates with a single outlet orifice (10), and means for controlling the valve to keep it pressed against its seat or to move it apart, respectively from the closing positions and valve opening, characterized er :: that it comprises a united sealing ring (21) enitouranit the tail (3) of the body (2), this ring (21) having a united threaded part initernia (22) which is screwed onto a single thread provided on a plain cyliridriqua part (23) of the body (2) located above the tail (3), the ring ( 21) has, in its lower front face, a transverse annular groove in which is housed a single O-ring seal (24) which vierit airisi apply on the upper surface of the collar (1), was compressed and crushed cutter this surface, to ensure a uniform taper at this point, and moreover the ring (21) also presents in the upper part of its internal wall, united transverse erinular groove in which is housed in another seal (25) is applied against a united cylindrical part (26), of the same diameter, of the body (2) which is situated above the threaded cylinidriqua part (23) of the body (2)  2. Robiriet according to claim (1), from which the valve (8) is isolated from the outside by transverse metal membranes held in abutment, by their marginal parts, on a single annular shoulder (16) of the body (2 ) on which they sound pressed by a single guide nut (17) traversed axially by a plain control rod (18), characterized in, that it comprises, above the membranes (15), plain first toroidal joirit (26) which is housed in a plain trarisversal aniniular groove in the lower part of the lateral surface of the guide nut (17), united slightly above the shoulder (16) serving as support for the members (15), or bierl in a united trarisversale annular groove provided in the wall of the body (2) receives the lower part of the guide nut (17), and a second O-ring seal (27) provided between the upper parts of the nut -guide (17) and the control rod (18), being housed in a transverse annular groove provided with reefs on the internal face of the guide nut (17), above its internal thread, or in a plain groove made of the control rod (18).  3.- Tap according to reverldicatiorl 1 danis which the valve (8) is isolated from the outside by a bellows (31) fixed at its lower end to the valve (8) and, at its upper end, to a plain washer guide (33) which is traversed by a solid push rod (32) at the end of which the valve 8 is fixed, characterized in that it comprises a first O-ring seal (34) interposed between the guide washer ( 33) and the push rod (32), being housed in a groove made either in the washer (33) or in the push rod (32), and second and third joir, toric sealing ts (47,48 ) housed in three-way grooves and irposed between rod rod (35) for controlling the push rod (32) dor, t is integral with the valve (8), and a single member (36,42) in which the control rod moves (35).