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(11) | EP 0 080 734 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Valve for fuel gas cylinders |
| (57) A valve comprising a spring-loaded, ball-shaped valve body (28) is provided for closing
a gas container. The valve includes a gas inlet canal (31) which has a relatively
wide diameter and which after filling the container will be closed tightly by means
of a capsula (30). The capsula (30) comprises an elastic sealing part having a pipe
connection (29) which penetrates into the gas inlet canal (31). The pipe connection
(29) reduces the diameter of the gas inlet canal (31) and forms the valve seat for
the valve body (28). In operation, a pressure reduction valve is seated on this valve.
The pressure reduction valve includes a connection cannula piercing through the capsula
(30) and removing the valve body (28) from its seat. |
1. GENERALITIES
[0001] The fuel gases existing at present in the market are supplied to the consumers under one of the two following physical states:
- Gaseous state.
The distribution to the consumer is made through adequate pipe-lines.
- Liquid state.
The distribution to the consumer is made by using liquefied gas containers.
[0002] It is second case that one of interest to us, because our invention is for application in the referred containers.
[0003] The above mentioned containers are, generally, cylindrical steel bottles, commonly named "gas cylinders" or "gas bottles".
[0004] It is common knowledge that there are in the market a lot of cylinder models, of various sizes, generally constructed in steel-sheet, and are sold containing a certain quantity of liquefied fuel gas.
[0005] These cylinders are fitted with a component part 1 (Dwg. No. 1) named "valve", which is generally threaded in the upper part of the cylinder. This component part owing to its characteristics and through an adequate operation allows to establish a communication between inside and outside of the cylinder, allowing thus both the gas inlet into the cylinder (filling) and the gas outlet from the cylinder (consumption).
[0006] The part 1 (Dwg. No. 1) performs in full its function in the cylinder filling operation, but it is not enough to permit the normal consumption of the gas contained in the cylinder. This happens because the gas is not generally consumed at the pressure at which it is liquefied into the cylinder.
[0007] It will be therefore necessary to have another component part named "pressure regulator" 2 (Dwg. No. 1) which is adjustable to the "valve" and receives through it the gas coming from the cylinder reducing its pressure to the values required by legal rules existing for the consumption of liquefied fuel gases.
[0008] "Valve" and "Pressure Regulator" form together a necessary whole when it is required to use liquefied fuel gas from cylinders.
[0009] With regard to the "valve" it is convenient to emphasize that what will be exposed next is referring to "self-closing" valves and therefore it will not be of interest to refer here to "manual-closing" valves, as our invention is mainly useful in "self-closing" valves although it can be used too in "manual-closing" valves.
2. DESCRIPTION OF EQUIVALENT MATERIAL ALREADY KNOWN
2.1 - VALVE
2.2 - REGULATOR
[0011] In the Dwg. No. 3 it is shown a schematized pressure regulator widely used all over the world. It is composed of the following main parts:
2.3 - VALVE-REGULATOR SYSTEM
[0012] In the Dwg. No. 4 it is shown the sequence of operations leading to the connection of the regulator to the valve. The fig. 1 shows the two parts of the system in position before connection. In the fig. 2 the regulator was introduced in the upper part of the valve and the regulator inlet connection 11 can be seen introduced at the valve outlet canal 2 passing through the connection joint 6 but the clamping system has not yet reached the final security position.
[0013] In the fig. 3 the regulator can be seen completely introduced in the valve and the security system (12 and 24) is already in the final position. However, the valve is still closed.
[0014] In the fig. 4 the handle 13 which makes the stem 14 to come down by intermediary of the eccentric 23 and opens the plunger 3 has already been turned round. Henceforth, the gas will pass inside the regulator until it will reach the outlet canal 15 for consumption.
3. MAIN INCONVENIENCES OF THE EXISTING VALVE-REGUALTOR SYSTEMS
[0015] The main inconveniences of the systems used at present are found in the sealing between the valve and the regulator and even in the own valve before the regulator being applied to it.
[0016] 3.1 - Any of the valves known (Dwg. No. 2) has a canal 2 allowing the passage between the interior and exterior of the cylinder. This canal allows the cylinder to be filled with gas and it is also suitable (in the inverse direction) for the gas outlet for consumption.
[0017] The referred canal diameter, which varies according to the manufacturer, is usually of 6 to 8 mm.
[0018] This diameter has to be of this size so that the cylinder filling is made quickly (15 to 20 seconds) in order that the filling plants are profitable. However; the discharge capacity of this canal is very excessive in respect of the normal consumption requirements, as the average consumer would consume a cylinder content within 15 to 20 days. In this way, the relation between the filling speed and the normal consumption speed in the referred canal, assuming that the useful time of utilization is 10% of total time to empty a cylinder (15 days) at the consumer home, will be:
V = Filling speed
v = Consumption speed
T = Consumption time
t = Filling time
[0019] The purpose of this simplified and not accurate calculation is just to have an idea of the difference between the gas speed to fill the cylinder and the gas speed at the connection joint area for consumption. We are considering here neither pressure losses nor effective pressures which are not identical for both cases.
[0020] In practice what is found by testing is that the necessary valve outlet canal diameter to guarantee the normal consumption gas flow is sized between 1.2 and 1.8 mm for cylinders internal pressures of 7 kg/cm2 and 0.5 kg/cm2 respectively.
[0021] In conclusion we can say that the inlet and outlet canal 2 (Dwg. No. 1) existing in the conventional valves has the suitable diameter for a quick filling, but it is very excessive for the consumption. Thus, a gas leak can occur more easily during the consumption because larger diameters have to be used in the valve-regulator connection than those really necessary.
[0022] The probability to occur a gas leak at connection joint will be increasing with the diameter of canal 2 (Dwg. No. 2).
[0023] 3.2 - In the valves existing actually in the market the upper area where is made the regulator connection (see Dwg. No. 5) is subject not only to the entry of all kind of foreign matter, such as, sand, dust, etc., but also to deliberated or accidental mechanical actions with instruments that can affect the seat disc 4 (Dwg. No. 2) and connection joint 6 (Dwg. Nos. 2 and 5).
[0024] When this happens, the valve can stop guaranteeing a good gas sealing and cause danger situations and fuel gas losses.
[0025] This type of situation is frequent in practice because the cylinders are travelling from the filling plant to the consumer without the regulator fitted in the valve as the regulator is a consumer's property and is fitted when the consumer starts using a new bottle.
[0026] The efficiency of the transport plugs used in some valves is very discussible, because normally they are not duly fitted or have been lost during the transport.
[0027] In the Dwg. No. 5 are shown three types of valves well known in the market. The areas subject to foreign matters are shown in vertical broken lines.
[0028] In short, we can say that the main inconveniences of the existing valves are:
a) Just one canal for filling and consumption with an overdimensioned diameter for the consumption. A gas leak can happen more easily than if a reduced diameter would be used.
b) The principal sealing parts of the valves are easy to reach from the exterior, allowing that fuel losses occur purposely or accidentally during the cylinder transport from the.filling plant to the consumer home and also that the referred leak continues at the consumption place with the inherent dangers.
c) As there are important areas of the valve- respecting to the sealing which are subject to the entry of foreign matters (see Dwg. No. 5) we cannot be sure that, when fitting the regulator, its gas inlet connection 11 (Dwg. No. 3) will guarantee a good sealing in the connection joint 6 (Dwg. No. 2) and it can happen that gas leaks occur, in that area, at the consumer home.
[0029] 3.3 - With regard to the regulators existing in the actual market, a description of which was already made in the Dwg. No. 3, there are not so much inconveniences, in respect to the regulator we are introducing, as in the case of the valves.
[0030] However, they have a common characteristic, which is not advisable, consisting in the fact of not allowing the consumption gas passage closing independently of the valve closing (see Dwg. No. 4). There is , thus, the possibility of the volume of gas contained at the nozzle 16 downstream, to come back to the atmosphere when the regulator is removed from the valve.
[0031] Furthermore, all them dispose of a fixing system to the valve (see Dwg. No. 3) very robust mechanically to resist to the big forces that, in the system, tend to remove the regulator from the valve (see Table No. I) which are due to the existing excessive sections.
[0032] There are also in the referred regulators interlocking systems (see Dwg. No. 4 - fig. 4) not allowing the regulator to be fitted or removed from the valve without closing previously the gas in the seat 5 (Dwg. No. 4).
[0033] Taking into account that the valves are self-clos- ing type, these systems would be useless if it there would be smaller sections in the connecting area, what would reduce, as it can be seen in the Table I (Capsula System), the total ejection force exerted in the regulator to insufficient values to eject it.
[0034] Explained the main inconveniences of the conventional valve-regulator systems existing in the market, we will be relating now what was tried to put into practice with the new system which is intended to apply for patent.
4. INVENTION PURPOSES
[0035] In view of the exposed before the purposes to be reached with the new Valve-Regulator system are as follows:
4.1 - To reduce the canal diameter 2 (see Dwg. No. 2) when the system is in gas consumption service without reduction of the filling canal diameter.
[0036] The solution of this point will reduce strongly the gas leak possibilities, when connecting the regulator to the valve, in view of the small sections used.
[0037] 4.2 - To avoid that the valve area (see Dwg. No. 3), where the main sealing parts 5 and 6 (Dwg. No. 5) are found, could be easily reached from outside either by foreign matters, that can be lodged in that area, or by mechanical parts introduced purposely.
[0038] The solution of this point will lead to a great fuel economy and also to the reduction of accidents caused by gas leaks.
[0039] 4.3 - To become the valve completely inviolable, and consequently the cylinder, too, during the transport from the filling plant to the consumption place.
[0040] The solution of this point will guarantee fuel economy, will reduce accident risks and will guarantee to the consumer the right quantity of gas he acquired.
[0041] 4.4 - To guarantee that the forces proceeding from the cylinder internal pressure action on the regulator connection 11 (Dwg. No. 4) are insufficient to eject it becoming unnecessary any special fixing mechanical system between part 1 and part 2 of the system (Dwg. No. 1).
[0042] The solution of this point allows a great simplification in the regulator construction leading to lower cost prices.
[0043] 4.5 - To become the consumption gas closing independent from the valve, being that operation made just in the regulator.
[0044] It would be thus avoided leaks of the gas contained downstream of the nozzle 16 (Dwg. No. 4) when the regulator is removed from the valve.
[0045] 4.6 - To get that the gas closing inside the regulator will be done automatically when the regulator is removed from its lodging in the valve and that will be maintained in that position while it is not opened manually.
[0046] The solution of this point will avoid that when placing the regulator on the valve the gas will pass immediately to the outlet canal 15 (Dwg. No. 3).
5. INVENTION DESCRIPTION
5.1 - Composition of parts 1 and 2 (Dwg. No. 1)
5.1.1 - VALVE
5.1.2 - REGULATOR
[0048] The regulator is composed as shown on Dwg. No. 7 in gas closed position. The components are as follows:
5.1.3 - VALVE-REGULATOR SYSTEM
[0049] In the Dwg. No. 9 it is shown the Valve-Regulator system in its sequential connecting positions.
5.2 - OPERATING PRINCIPLE
5.2.1 - FILLING (see Dwg. No. 8)
[0050] The valve is threaded in the cylinder upper part and it is submitted to filling operation without the parts 29 and 30 (fig. 1 - Dwg. No. 8). In this stage the ball 28 is actuated by the spring 34 against the seat 33.
[0051] In the filling plant it is adjusted to the part 27 a device 54 (Dwg. No. 8) specially studied for that purpose which is connected to the high pressure gas line.
[0052] The gas under pressure will pass into the canal 31 forcing the ball 28 to come down. Then the gas will pass between the seat 33 and the ball 28 to inside of the cylinder.
[0053] Once the cylinder is full of gas which can be proved through weighing devices already known, the filling device is removed and the ball 28 actuated by the spring 34 and the gas pressure in the cylinder cares back to the initial position guaranteeing the complete cylinder closing by sealing the seat 33 (fig. 3 - Dwg. 8).
[0054] In the second station of filling plant the parts 29 and 30 are introduced in the upper part of the valve by means of a special device 55 (Dwg. No. 8) which effects not only this introduction but also clips firmly part 30 in the groove 53 existing in part 27 guaranteeing thus the complete tightness and inviolability of the gas cylinder.
[0055] At the same time, the ball 28 will be slightly pushed down when the bottom side of part 29 touches it loosing the contact with part 33 (fig. 4 - Dwg. 8).
[0056] The part 30 being made in brass-sheet and having a central hole 56 and the part 29 (see Dwg. Nos. 6 and 9) being designed with a special shape are allowing the introduction through them of the regulator gas inlet connection 36, which will be adjusted in the internal orifice of part 29 (2.5 mm diameter) as shown on Dwg. No. 9.
[0057] It will be possible with this new system:
1) To use for filling the canal 31 with a diameter of the order of 6 mm.
2) To replace that canal by the canal of 2,5 mm diameter existing in part 29 for consumption.
3) That the ball 28 effecting the gas sealing in the seat 33 for filling purposes, will be pushed down slightly and, loosing the contact with the part 33, starts sealing the gas in the bottom of part 29 (2,5 mm diameter orifice). This orifice will be ready from now to operate as consumption seat (fig. 4 - Dwg. No. 8).
4) That the valve area where the main sealing parts are found is completely protected from the entry of foreign matters.
5) That the valve-cylinder system is quite inviolable during the way from the filling plant to the consumer.
5.2.2 - GAS CONSUMPTION
[0059] Once effected the filling, as explained in 5.2.1, the cylinder is sent to the consumption place where the pressure regulator is adjusted to it (see Dwg. No. 9).
[0060] In the fig. 1 it is shown how the regulator is applied. The needle-shaped gas inlet connection 36 with an outside diameter of 2,5 mm will be piercing (fig. 2) in the center of the part 29 through the hole 56 existing at the center of part 30 and it will be introduced in the referred part, jointing closely, in order to guarantee a good gas sealing between parts 29 and 36.
[0061] The part 36 on coming down inside the part 29 will be pushing down the ball 28 pressing the spring 34 opening thus the gas passage to the part 36 internal canal (1,8 mm diameter).
[0062] The ejection force exerted by the gas pressure on the part 36 owing to its small cross section (see Table I) is insufficient to expel the part 36 (and consequently the regulator) from its lodgement in the part 29 reason why it will not be necessary any fixing system between valve and regulator.
[0063] The gas will pass then up to the regulator chamber 51 but it will not reach the outlet canal 38 because the gas on-off system composed of parts 37, 46, 47, 48, 49, 50 and 52 is in the most advanced position, closing the chamber 51 owing to the action of spring 49 (fig. 2).
[0064] The user must then turn round the lever 37 which will make rove the on-off plunger 47 by means of the helical ramp 46 and ramp pin 50 pulling the spring 49 to the most backward position (fig. 3 - Dwg. No. 9) opening the chamber 51 and allowing the gas passage to the gas outlet canal through the nozzle 39 and thence to the gas consumption.
[0065] The on-off plunger 47 will be maintained at its most backward position by the gas pressure action in chamber 51 which actuates on the forward surface of on-off plunger. The two O-Rings 48 are operating now as piston rings.
[0066] Obviously, it is possible for the consumer to close the gas passage at any moment by using the lever in the inverse direction of that he used to open the gas as the chamber 51 receiving the gas from the gas inlet connection 36 is ringshaped and on moving the plunger 47 ahead the chamber will be confined of both sides by the two O-Rings 48 existing in the stem end.
[0067] Should the regulator be removed wrongly from the valve before closing the gas, as indicated before, the pressure will break off at the forward plunger 47 surface and the spring 49 will move ahead automatically the plunger 47 and consequently the O-Rings 48 which will confine the chamber 51 as shown on fig. 2 (Dwg. No. 9) avoiding in this way that the volume of gas contained downstream can pass to the atmosphere through the gas inlet connection 36.
[0068] The automatic closing will avoid also that the regulator will be introduced in the valve in the "ON" position (gas opened) what could afford danger situations should the gas burner valves be opened.
[0069] It will be possible with this new system:
1) To guarantee that the gas pressure action will not eject the regulator from its lodging in the valve, becoming unnecessary any complex mechanical fixing systems.
2) To turn the gas flow off independently of the closing of the valve.
3) To obtain the automatic gas closing when the regulator is removed from the valve and maintain this situation while the consumer will not actuate voluntarily to open the gas.
5.2.3 - REFILLING (see Dwg. No. 10)
[0071] Once the gas contained in the cylinder is consumed the consumer will remove the regulator from the valve and will send the cylinder with the valve to the filling plant.
[0072] The filling plant must remove the parts 29 and 30 from the valve so that the system comes back to the same position as indicated in 5.2.1 and according to fig. 1 (Dwg. No. 8).
[0074] The part 29 is made in synthetic rubber and its sizes studied in such a way that, when exerting a compression with a specially designed device 57 (Dwg. No. 10) at its top the volume of the rubber contained between the parts 27 and 30 flows hydraulically to the periphery exerting an adequate force in the interior surface of the "capsula" 30 to extract it from the groove 53 (fig. 2 - Dwg. No. 10).
1. Valve for fuel gas cylinders characterized by a gas inlet canal inside which there
can be lodged, after the bottle filling operation, a part containing another canal
of smaller diameter which will be used for the consumption of the gas.
2. Valve according to claim 1, characterized in that the part containing the smaller
canal has not this canal completely opened when that part is introduced in the larger
diameter canal after filling opera- tion, guaranteeing thus a complete tightness of the bottle and allowing the consumer to
complete the perforation by means of a suitable perforating part existing in the regulator
which is always necessary to be used for reduction and stabilization of gas pressure
for normal consumption.
3. Valve according to claim 1 or 2, character- ized by a part (Capsula) that can be
clipped firmly to the valve body, by means of a suitable tool, guaranteeing a perfect
lodgement of the part containing the smaller canal and allowing a good tightness between
inside surface of larger canal and external surface of part containing smaller canal
and further guaranteeing the inviolability of the cylinder.
4. Valve according to claim 1, 2 or 3, charac- terized in that the part containing
the smaller canal is obtained from a raw material that can resist to the chemical
action of the fuel gas and support its pressure guaranteeing the tightness of the
valve.
5. Part of the valve according to claim 3 and 4, cha- racterized by being designed
in such a way that it has a calculated volume and a geometry such that, when compressed
by the part called "Capsula", allows to obtain the characteristics as claimed in claim
3 and when subjected to a mechanical deformation, by means of a suitable tool, can
extract itself together with the part "Capsula" from the valve body without destroying
this body.
6. Pressure regulator to apply in fuel gas cylinders, comprising a valve part according
to claim 2, cha- racterized by having an incorporated perforating part shaped as a
hollow needle designed so that can perforate easily the valve part and thus to allow
to take the gas out the cylinder for consumption.
7. Pressure regulator according to claim 6, charac- terized by the perforating part
having a diameter small enough to avoid the mechanical clamping between regulator
and valve.
8. Pressure regulator according to claim 6 or 7, cha- racterized by having inside
it a device that allows to cut the gas flow automatically when the regulator is removed
from the valve and guarantees that gas flow will be shut off when inserting the regulator
in the valve.