EP0496091B1 - Valve for compressed or liquefied gas bottles - Google Patents

Description

The present invention relates to a valve for compressed or liquefied gas bottles, comprising a body designed to be screwed onto a gas bottle, an internal closure member with a sealing surface at the intersection of a gas outlet passage. and of a channel in communication with an intake passage, an external operating means connected, through the body, to said closing member to move the latter, against the action of elastic means, between an open position and a closed position and a regulator for controlling the gas flow pressure in the open position of the closing member.

Although not limited thereto, the invention relates more particularly to a valve with a pressure reducing valve ensuring a pre-expansion of the gas so as not to be obliged, when filling a bottle, to have to take account of the operating pressure or the performance of the regulators provided in the use circuits. This allows, in particular to further compress the gas in the bottle during filling, in other words, with equal capacity of the bottle, to increase its content, that is to say, the amount of gas, or, with equal content , to reduce the size of the bottle.

Unfortunately, the mounting of regulators directly on the bottles requires, most often, their disassembly for the filling of the bottle, because the filling cannot be carried out through a regulator, this allowing only one-way circulation some gas.

To remedy this, US Pat. No. 4,844,111 proposes a regulator which is provided with a second orifice serving only for filling the bottle and communicating directly with the interior thereof. This regulator has the disadvantage that, when filling the bottle, it is necessary to close the gas withdrawal orifice, and vice versa, when withdrawing, the filling opening must be closed.

Valves with neutralizable regulators have also already been proposed comprising relatively complicated means for neutralizing the action of the regulator by blocking it in a non-operative position when filling the bottle.

The object of the present invention is to provide a new tap of the type described in the preamble which allows the filling of the bottle and the withdrawal of gas through the same opening.

To achieve this objective, the valve proposed by the present invention is essentially characterized by a bypass line through the body of the valve, between the intake passage and the channel, short-circuiting the regulator and provided with means allowing the flow filling gas from the outlet passage to the intake passage and preventing reverse gas flow.

Said means are preferably constituted by a non-return valve. Another non-return valve is provided between the regulator and the closing member. This non-return valve allows the withdrawal of gases through the regulator but prevents the penetration of gases into the regulator during filling. This valve does not normally allow the gas cylinder to be emptied beyond a lower pressure threshold corresponding to the closing pressure of the valve. To be able nevertheless to offer, if necessary, the possibility of completely emptying the bottle, for example by connecting it to a vacuum pump, the valve is preferably neutralizable from the outside by mechanical or magnetic means.

The valve also includes a safety valve, known per se. This is preferably provided in a fitting through which the outlet passage passes in a location such that it is masked by a first adaptable connector on the connection for filling the cylinder and that it is not masked by a second connector adaptable on the same connection for the withdrawal of gases.

• la figure 1 montre un schéma synoptique des deux modes de fonctionnement d'un robinet selon la présente invention;
• la figure 2 montre une coupe axiale à travers un mode d'exécution d'un robinet fonctionnant selon le principe de la figure 1, la figure 2a montre la position de la soupape de sécurité et
• la figure 3 montre les détails d'un mode d'exécution préféré d'un clapet anti-retour.

Other features and characteristics of the invention will emerge from the detailed description of an advantageous embodiment presented below, by way of illustration, with reference to the appended figures in which:

• Figure 1 shows a block diagram of the two operating modes of a valve according to the present invention;
• FIG. 2 shows an axial section through an embodiment of a tap operating according to the principle of FIG. 1, FIG. 2a shows the position of the safety valve and
• Figure 3 shows the details of a preferred embodiment of a check valve.

We will first explain the operating principle of the valve according to the present invention with reference to the block diagram of Figure 1. The active elements of the valve are arranged between an outlet 60 of the valve and an inlet passage 62 in communication with the inside a gas cylinder not shown. The reference 64 designates the valve closing member, while the reference 66 designates a regulator, known per se, designed, for example, to reduce the gas pressure of the filling pressure, in this case for example the 'order of 300.10⁵ Pa of the bottle until the pressure, for example of the order of 90 to 120.10⁵ Pa of a circuit of use. The reference 68 designates a safety valve, known per se, designed to open in the event of overpressure, for example due to a faulty operation of the regulator. The references 70 and 72 each designate a non-return valve.

The drawing off of the gas under pressure takes place in normal operation, in a manner known per se, by the line 74 following the arrows in dashed lines through the regulator 66 and the open closing member 64. The novelty lies in the layout 76 comprising a bypass line bypassing the reducing valve 66 and connecting the outlet 60 to the inlet 62 through the closing member 64 leaving side of the regulator 66. This trace 76 represented by the arrows in solid lines therefore allows the filling of the bottle through the open closure member 64, the pressure of the filling gas allowing the opening of the non-return valve. 70. On the other hand, the non-return valve 72 prevents the filling gas from flowing through the pressure reducing valve 66. The non-return valve 70, on the other hand, prevents the gases from following the course 76 during the withdrawal. requires taking the passage through the regulator 66 and its non-return valve 72 which opens under the pressure of the expanded gases.

We will now describe, with reference to Figures 2 and 3, an advantageous embodiment of a valve operating according to the principle of Figure 1. This valve has a body 78 whose lower part is provided with an external thread 79 allowing it to be screwed onto a gas cylinder not shown. The lower part of the body 78 is crossed by an inlet pipe 62 in communication with the interior of the bottle, while the upper part of the body 78 is provided with an outlet radial passage 60 through a connector 80 on which can be connected either a gas use circuit or a cylinder filling circuit. The central part of the body 78 has radial housings for receiving the active elements illustrated in FIG. 1, namely the pressure reducer 66 as well as the non-return valves 70 and 72. The closing member 64 is located in the upper part of the body 78 of the tap. This closing member 64 is constituted by a piston 82, the lower part of which comprises a sealing pad 84 cooperating with a seat 86 surrounding an axial channel 88. The outlet passage 60 is in communication with the annular space surrounding the seat 86.

The upper part of the valve comprises an operating handwheel 90 acting by means of a rod 92 on the piston 82. FIG. 2 shows the handwheel 90 in the closed position in which the pellet 84 is applied in a sealed manner to its seat 86 When the handwheel 90 is loose, the piston 82 is raised under the action of an appropriate mechanical means such as a coil spring, thereby lifting the pellet 84 from its seat 86 and establishing communication between the channel 88 and the outlet passage 60.

In accordance with the principles of FIG. 1, the intake line 62 can communicate with the channel 88 through the pressure reducer 66, the line 74 and the non-return valve 72, while the channel 88 can also be put in communication with the inlet line 62 through the bypass line 76 and the non-return valve 70.

In the example shown, the two non-return valves 70 and 72 are identical to each other. They essentially consist of a piston 94 sliding in a cylindrical axial housing of a plug 100 screwed into a suitable fitting of the body 78 of the valve. The piston 94 has a frustoconical inner head provided with a seal 98 intended to cooperate with a corresponding seat 96 of the valve body. The piston 94 is influenced by a calibrated interior spring 102 whose action tends to keep the piston 94 in a sealed manner on its seat 96. The piston 94 is, moreover, axially pierced at 104 so as to ensure equalization pressure on either side of piston 94.

The regulator 66 comprises, in a manner known per se, a piston 106 mounted radially in a cylindrical bore of the body 78 with a seal 108 capable of closing a radial passage 110 between the housing of the piston 106 and the intake pipe 62. The piston 106 is subjected, in the direction of its opening to the action of a spring 112 which is calibrated to ensure a determined degree of relaxation. The section on the inside of the piston 106 is slightly smaller than the section on the outside thanks to a peripheral shoulder 114 and a corresponding enlargement of the bore in which the piston 106 slides. This piston 106 is provided with an axial channel 116 establishing communication between its two opposite bases.

The tap is also provided with a safety valve 68 which, in the embodiment shown, is provided in the connector 80 (see FIG. 2a). This valve is constituted, in a manner known per se, by a collapsible membrane when the pressure of the gas supplied to the use network exceeds a predetermined safety threshold, for example in the event of malfunction of the regulator 66, this to release the gases and avoid the explosion of the bottle. The valve 68 is preferably provided in a cylindrical section of the connector 82 between two successive conical seats 120 and 122.

We will now describe the operation of the valve for the two operating modes explained with reference to Figure 1. In order to fill a cylinder with a gas under high pressure, for example 300.10⁵ Pa we screw on the connector 80 a connector not shown, provided with a seal, which, when the connector is screwed onto the connector 80 is pressed in a sealed manner on the interior seat 120. This prevents the safety valve 68 from being exposed to the filling gases under high pressure, at which its membrane would burst. After the opening of the handwheel 90, the pressurized gas flows in the axial channel 88 and the bypass pipe 76. The gas pressure is exerted on the head of the piston 94 of the non-return valve 72, but, as a result of the axial opening 104 in the piston, the pressure is equalized on either side of the piston and as a result of the higher section on the side of the spring 102 the differential pressure of the gas on the piston 94 keeps the valve 72 in the closed position. The valve 72 therefore exercises its non-return function during filling. Admittedly, the pressurized gas could not pass through the regulator 66 via the line 74 since the passage through a regulator is always a one-way, but the valve 72 prevents the high pressure of the filling gas being exerted on the regulator and causes rapid wear of its seal 108 as a result of the high force which applies it to its seat.

In the non-return valve 70 the gas pressure is exerted on the peripheral region of the neck 96 of the piston 94 and lifts it from its seat against the action of the spring 102 so that the gas under pressure can flow freely through the open non-return valve 70 and the passage 62 towards the interior of the bottle.

As soon as the filling pressure falls, for example following the closing of the handwheel 90, below the pressure exerted by the spring 102 on the non-return valve 70, the latter closes automatically. Appropriate calibration of the spring 102 makes it possible to fix this closing threshold of the valve 70 at a determined pressure, for example of the order of 4.10⁵ Pa.

To connect the bottle to a usage circuit, a connector (not shown) provided with a seal is screwed onto the connector 80, this time being applied in a sealed manner to the seat 122 of the connector 80 or to the inlet. of the fitting 80 so that the safety valve 68 is subjected to the action of the expanded gas leaving the valve and can exercise its function in the event of abnormal overpressure.

During withdrawal, the non-return valve 70 operates in the same way as the valve 72 during filling, that is to say that the high pressure of the gas is exerted, thanks to the passage 104 of the piston 92 on both sides of it and keeps it in the closed position, thus forcing the pressurized gas to pass through the regulator 66.

Since the high pressure of the gas leaving the cylinder is exerted on both sides on the piston 106 of the regulator 66 and that the outside section of the latter is greater than its inside section the gas exerts a differential pressure on the piston 106 in the direction of its closure. The equilibrium position resulting from the action of this differential thrust and the thrust of the spring 112 thus determines the degree of relaxation of the gases which is determined by an appropriate calibration of the spring 112, generally of the order of 90 to 120.10⁵ Pa. The gas expanded at this reduced pressure flows through line 74 to open the non-return valve 72 in the same way as the valve 70 opens under the action of the pressure of the filling gas. The expanded gas can therefore flow through the non-return valve 72 open in the operating circuit, provided that the closure member 64 is open.

When the pressure in the gas cylinder falls below the expansion pressure to which the regulator 66 is adjusted, the latter ceases to produce its effects under the action of its spring 112 which keeps it in the open position so that the gas, no longer requiring expansion, can flow freely through the pipe 74 and the open valve 72.

When the pressure in the gas cylinder falls to a value corresponding to the force exerted by the spring of the non-return valve 72 the pressure of the gas is no longer able to keep the non-return valve open so that it closes under the action of its spring and stops the flow of gas to the operating circuit. This minimum pressure which depends on the calibration of the spring of the non-return valve 72 can be of the order of 1.5 to 2.10⁵ Pa. In other words, the valve 72, in addition to its intrinsic functions of only allowing gas flow to sense single, prevents a complete emptying of the gas cylinder beyond a residual pressure corresponding to the calibration value of its spring. Maintaining such a minimum gas pressure in the bottle has the advantage of preventing the penetration of impurities and moisture into the bottle before refilling, even when the closure member has been forgotten. main closure 64.

If it is useful to be able to maintain a residual pressure in the bottle to prevent the penetration of impurities, it may be necessary to empty it completely from time to time by connecting it to a vacuum pump, in particular for rinsing . To this end, it is useful to provide means to be able to neutralize the action of one of the two non-return valves 70 or 72. FIG. 3 shows, as a variant, the medallion of FIG. 2 and illustrates a exemplary embodiment of a neutralizable non-return valve. In this embodiment, the piston 130 which forms the shutter member is slidably mounted in the cylindrical housing of a plug 132 which is screwed into the body 78 of the valve. The housing of the shutter member 130 has an inner retaining edge 134 cooperating with a peripheral shoulder 136 of the shutter member 130. When the plug is screwed fully into the body 78 of the valve, as shown in the lower part of FIG. 3, the freedom of movement of the member 130 is not disturbed by this peripheral edge 134. On the other hand, when the plug 132 is unscrewed, as shown on the upper part of FIG. 3 the member 130 is raised from its seat under the effect of the action of the edge 134 on the shoulder 136. By further unscrewing the plug 132 the member 130 is completely disengaged from its seat and the valve is thus neutralized in a position of opening, which allows the bottle to be completely emptied and, if necessary, connected to a vacuum pump.

It is possible to provide other means for neutralizing the valve than those shown in FIG. 3. For example, it is possible to provide the shutter member 130 with a rod axially and sealingly passing through the plug and capable of be actuated from the outside by mechanical or magnetic means to lift the member 130 from its seat against the action of its spring.

Instead of providing for the neutralization of the valve 72, one could, in principle, make the valve 70 neutralizable. It is however preferable to provide for the neutralization of the valve 72 since the latter is located downstream of the regulator 66 and does not undergo, like the valve 70, the high pressure of the gas in the bottle, this to counter any possibility of negligence or forgetting to put the non-return valve back into service after neutralizing it.

It finally remains to emphasize that, if a tap as shown in FIG. 2, that is to say with the pressure regulator provided below the valve 72 and the valve 70 below the connector 82 is practicable, this arrangement has been chosen for the purposes of description and clarity of the figure. In practice, in order to make the valve more compact, in particular in the axial direction, the regulator 66 and the valve 70 are provided approximately at the level of the valve 72 and the connector 82 and arranged in a cross with respect thereto.

Claims (8)

1. A faucet for bottles of compressed or liquefied gas, comprising a body designed to be screwed onto a gas bottle, an inner closure member (64) with a sealing surface at the intersection of a gas-outlet passage (60) and a channel (88) communicating with an intake passage (62), an outer operating means (90) connected, through the body, to said closure member (64) in order to displace the latter, counter to the action of mechanical or elastic means (94), between an open position and a closed position, and a pressure reducer (66) for controlling the pressure at which the gas flows out in the open position of the closure member (64), which comprises a duct (76) branched through the body (78) between the intake passage (62) and the channel (88), short-circuiting the pressure reducer (66) and provided with means enabling the filling gas to flow from the outlet passage (60) to the intake passage (62) and preventing gas from flowing in the opposite direction.
2. The faucet as claimed in claim 1, wherein said means consist of a non-return valve (70).
3. The faucet as claimed in either of claims 1 and 2, which comprises a non-return valve (72) between the pressure reducer (66) and the closure member (64).
4. The faucet as claimed in claim 3, wherein the non-return valve (72) can be neutralized from outside.
5. The faucet as claimed in claim 4, wherein the non-return valve (72) comprises a shut-off member (130) which is subjected to the action of a spring and mounted inside a plug (132) screwed into a socket of the body of the faucet and the unscrewing of which frees the passage in both directions through the non-return valve.
6. The faucet as claimed in claim 5, wherein the plug comprises a cylindrical housing for the shut-off member, and wherein the housing is provided with an inner edge (134) interacting with a peripheral shoulder (136) of the shut-off member.
7. The faucet as claimed in claim 4, wherein the valve comprises a shut-off member (130) subjected to the action of a spring and mounted inside a plug (132), and wherein the shut-off member (130) can be maneuvered, from outside by magnetic means, via a rod connected to the shut-off member (130) and traversing the plug (132) axially and in sealing fashion.
8. The faucet as claimed in any one of claims 1 to 7, which comprises a safety valve (68) provided in a socket (80) traversed by the outlet passage (60) at a location situated between two frustoconical seats in such a way that it is masked by a first connector which can be fitted to the socket in order to fill the bottle, but that it is not masked by a second connector which can be fitted to the same socket in order to draw off the gas from the bottle.

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