AU2021200123A1 - Gas Cooker Isolation Valve - Google Patents

Abstract

A gas ball valve (30) is disclosed having a generally L-shaped housing (34) having a quasi-spherical ball having a through hole, a handle (33) mounted on the housing to permit the ball to be rotated between valve open and valve shut 5 positions, and a valve outlet and a valve inlet in communication with the ball. The valve outlet takes the form of a male thread (38), the valve inlet takes the form of a swivel nut (36) and a metal dome (37). The metal dome has a central bore (41) in communication with the ball, and the handle is located opposite the valve inlet. A method of installing a gas cooker to connect same to the 10 male thread of the gas supply pipe, and a gas installation valve for a gas cooktop to be supplied with gas via an "easy hooker" style of flexible hose, are also disclosed. 5183BQ-AU 15 9/q ' t i-i.. - 3 I )4. I-33 VA . ,_ _ _4 yA~~*~ ~ 17 3A tl 7 t1

Description

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"Gas Cooker Isolation Valve"

Field of the Invention The present invention relates to isolation valves for gas cookers or cooktops.

Background Art Gas has long been used in domestic and commercial premises as source of energy for cooking. Because gas is invisible, explosive and poisonous many regulations specifically relating to gas are in force in Australian. Such regulations include Australia/New Zealand Standard AS/NZS 5601 and such standards are quite different from the standards and regulations governing water supply and reticulation such as AS/NZS 3500. For such reasons plumbers require an additional qualification in order to be qualified to act as gas fitters. It is also possible to qualify as a gas fitter without being a plumber.

While some items of hardware such as pipes and elbows are able to be used for both gas and water applications, in general many hardware items, and valves in particular, are differentiated according to whether they are intended for use with gas, or are intended for use with water. There are various structural and/or operational reasons for this.

For example, a major point of differentiation between gas and water valves is that valves for water are able to use jumper valves and ceramic disc quarter turn type valves which are unsuitable for control of gas flow. Because of this operational difference, an industry convention has arisen that valves for water have green or blue handles and valves for gas have yellow handles so as to provide a visual indication because a valve's interior construction is hidden by the valve housing.

Furthermore, some gas hardware items such as gas cylinders are provided with a left hand thread rather than a right-hand thread as a safety measure in order to deter people who are not gas fitters from assembling an installation including such left-hand thread devices.

5183BQ-AU 1

Similarly, most O-rings used in water valves are not suitable for gas valves and visa versa. Other areas of differentiation between gas and water valves include the pressure rating which is required to pass certification, different testing procedures for gas valves and water valves, and different requirements for the torque required to operate the valve handle for gas valves and water valves.

Still further, plumbers' sealing tape for sealing threaded water fittings is coloured white and is unsuitable for use with gas fittings since it is liable to deteriorate in contact with gas over time and therefore give rise to gas leaks. For this reason, gas fitters have a different type of sealing tape which is coloured yellow.

Traditionally gas cooking took place on a freestanding stove which included both an oven and gas burners. However, in recent years the number of freestanding stoves sold has declined. Furthermore, gas burners in the form of a gas cooker are now provided independently of any oven. This enables prospective purchasers to choose an electric oven, for example, in combination with a gas cooktop or cooker.

In particular, for gas cooktops AS/NZ 5601.1 Paragraph 6.6.3 specifies that it is necessary in commercial or industrial buildings and in residential apartment buildings to have an isolation valve adjacent the cooktop in order to permit the gas supply to be turned off in an emergency. The same standard requires only that such an isolation valve is optional for single residential dwellings, however, it is clearly desirable for such dwellings. Furthermore, given the preponderance of apartments being built in Australian cities of recent years, from a commercial point of view such an isolation valve is a significant item of commerce.

Furthermore, such an isolation valve needs to be at a location adjacent the cooktop, rather than the isolation valve being the main isolation valve for the premises. Usually such a main isolation valve is located adjacent the gas meter for the premises and therefore normally some distance from the cooktop. Since the cooker isolation valve is likely to be operated under emergency conditions, it is necessary (or desirable for single dwellings) for the cooker isolation valve to be both visually apparent and physically accessible. In most instances items closely adjacent the cooker such as

5183BQ-AU 2 bench tops, other appliances, and the like, means that the physical space available for such a cooker isolation valve is limited and the installer of such an isolation valve almost always finds that the installation is cramped.

A cooker isolation valve also is useful during initial construction if various gas appliances such as a gas cooker, a gas hot water system, and so on are supplied at different times. If the cooker isolation valve is installed before any appliances are delivered, the gas supply can be turned on and the isolation valve turned off before the gas cooker is delivered. After the gas cooker is connected, the isolation valve can then be turned on.

Hitherto a conventional in-line gas valve with a threaded inlet and outlet has been used as the isolation valve for gas cookers. The outlet of such an in-line gas valve is connected to the gas stove by a flexible hose known as an "easy hooker" flexible hose. The inlet of the in-line gas valve is connected to the male threaded pipe providing gas to the cooker by means of conventional threaded plumbing fittings. Usually such plumbing fittings involve the use of thread tape which requires some degree of skill on the part of the gas fitter lest there be too much tape, or too little tape, utilised.

When one looks at a catalogue of a supplier of plumbing fittings, one cannot help but be impressed, often to the point of being overwhelmed, by the number and variety of items available for sale. It seems that every conceivable size and shape of plumbing fitting and valve is available for selection by intending customers. However, it is not the case that such catalogues display every desired article since specialised applications can, and do, arise.

Genesis of the Invention The Genesis of the present invention is a desire to both fill such a product niche (and thereby expand the product range available to prospective purchasers to cater for specialised applications) and provide for an easier installation of such a gas cooker isolation valve by the gas fitter. In particular, there is a desire to avoid the need to use thread tape in the cooker isolation valve installation.

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Summary of the Invention In accordance with a first aspect of the present invention there is disclosed a gas ball valve comprising a generally L-shaped housing having a quasi-spherical ball having a through hole, a handle mounted on said housing to permit said ball to be rotated between valve open and valve shut positions, and a valve outlet and a valve inlet in communication with said ball, wherein said valve outlet comprises a male thread, said valve inlet comprises a swivel nut and a metal dome, said metal dome having a central bore in communication with said ball, and said handle is located opposite said valve inlet.

Preferably the valve is intended to isolate a gas supply to a gas cooker installed in a building. The gas supply takes the form of a male threaded pipe extending from a wall of the building and the gas cooker has a flexible "easy hooker" style connecting hose terminating in a conventional swivel nut and metal dome connector, the dome connector having a through passage leading to said hose, and the size of the central bore exceeds the size of the through passage.

According to another aspect of the present invention there is provided a method of installing a gas cooker to connect same to a male thread of a gas supply pipe via a gas isolation valve as defined above, utilising an "easy hooker" style of flexible hose which terminates in a nut and tail fitting, said method comprising the steps of, in any order,: connecting said flexible hose to said threaded valve outlet, and connecting said swivel nut and metal dome to said gas supply pipe male thread without the use of thread tape thereby placing said handle of said valve opposite said gas supply pipe and therefore in a position which is both visually apparent and physically accessible.

In accordance with a still further aspect of the present invention there is disclosed an isolation valve installation for a gas cooktop to be supplied with gas via an "easy hooker" style of flexible hose which terminates in a nut and tail fitting, the supply

5183BQ-AU 4 being from a gas supply pipe having a male threaded outlet, wherein said installation comprises a gas isolation valve as defined in above and having said nut and tail fitting of said flexible hose connected to the outlet of said gas isolation valve, and having the swivel nut and dome of said gas isolation valve connected to said gas supply pipe whereby said installation does not utilise sealing tape.

Brief Description of the Drawings A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. 1 is a side elevation illustrating the use of a conventional in-line gas valve as a cooker isolation valve and plumbing fittings to connect to the gas supply pipe, Fig. 2 is a perspective view of a known gas valve, Fig. 3 is a perspective view of another known gas valve, Fig. 4 is a side elevation similar to Fig. 1 illustrating the valve of the preferred embodiment being used as a cooker isolation valve without the need for additional plumbing fittings, Fig. 5 is a perspective view of the valve of Fig. 4, Fig. 6 is a side view of the valve of Fig. 4, Fig. 7 is the opposite side view of the valve of Fig. 6, Fig. 8 is an end view of the valve of Fig. 4, Fig. 9 is an end view of the valve of Fig. 4 looking in a direction opposite to that of Fig. 8, Fig. 10 is a cross-sectional view of the valve of Fig. 4 taken along the line X-X of Fig. 8, Fig. 11 is a schematic representation of the restricted access available for installation of a prior art gas cooker isolation valve assembly of the type illustrated in Fig. 1, and Fig. 12 is a perspective view similar to that of Fig. 11 but showing the valve of the preferred embodiment installed behind the drawer.

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Detailed Description As seen in Fig. 1, a gas supply pipe 1 protrudes from a wall 2 and presents a male thread 3. The gas supply pipe 1 is often located adjacent a floor 4 or other surface of the building. The gas pipe 1 is plumbed in during the construction of the building and is thus installed long before the installation (or re-installation) of a gas cooker (not illustrated). When the gas cooker is to be installed, a connection hose 5 termed an "easy hooker" has one end (not illustrated) connected to the cooker. The size of the gas inlet on the cooker is normally DN15mm (half inch) and this determines the size of the upstream components such as the connection hose 5, gas isolation valve and gas pipe 1.

The connection hose 5 is formed from flexible material, such as an elastomer, which is covered with stainless steel braiding. Two identical fittings are swaged to either end of the hose 5. One of these fittings 7 is connected to the other end 6 of the hose 5. The fitting 7 comprises a loose nut with an interior female thread and a metal dome having a through passage which leads to the interior of the hose 5. The fitting 7 is dimensioned to connect with the male thread 3 of the gas supply pipe 1. The internal diameter of the through passage of the metal dome of the fitting 7 is approximately 7mm.

Instead of being connected to the gas supply pipe 1, the fitting 7 is connected to a male thread at the outlet 9 of an in-line gas isolation valve 10. The gas isolation valve 10 has a handle 12 which faces away from the wall 2 and which is therefore both visually apparent and physically accessible.

The isolation valve 10 is connected to the supply pipe 1 by means of conventional plumbing fittings 14 such as an elbow 15. An important aspect of the plumbing fittings 14 is that in order to connect to the male thread 3 of the gas supply pipe 1, and the female thread 17 of the valve inlet 18, the gas fitter needs to utilise conventional thread tape (not illustrated). Either too much, or too little, thread tape can result in gas leaks, so the use of thread tape at all is to be avoided if possible.

5183BQ-AU 6

Usually there is enough distance between the male thread 3 of the gas supply pipe 1 and the floor 4 (or other surface such as a cupboard interior) to enable the elbow 15 to be rotated.

Turning now to Fig. 2, a gas valve 20 is illustrated which is known from plumbing catalogues but little used within Australia. The gas valve 20 has an inlet 21, an outlet 22 and a handle 23, all arranged around a generally L-shaped housing 24. The inlet 21 is a female thread. This requires the entire valve to be rotated about any stationary male thread to which the valve 20 is to be connected. The outlet 22 is a nut and tail connector which requires a gasket to effect a seal.

If the inlet 21 is to be connected to the gas supply pipe 1, this requires the valve 20 to be rotated around the supply pipe 3. Since the supply pipe 3 is typically close to the floor 4, or there are other possible obstructions, such as kitchen cupboards or kitchen benches adjacent the confined space allocated for the gas cooktop, it may well be impossible to rotate the valve 20 as required in this arrangement.

Similarly, as illustrated in Fig. 3, another gas valve 120 is illustrated which is known from plumbing catalogues but also little used within Australia. The gas valve 120 has a male thread at its inlet 121, an outlet 122 and a handle 123, all arranged around a generally L-shape housing 124. Because the inlet 121 is a male thread, this requires a female/female union and thread tape in order to connect the valve 120 to the male thread 3 of the gas supply pipe 1. Again this requires rotation of the gas valve 120.

It is theoretically possible for the valves 20, 120 to be installed in a "reverse" condition. That is, it would be possible to connect the outlet 22, 122 to the supply pipe 1. Whilst this overcomes the above-mentioned problems regarding rotating the valve 20, 120 it means that the handle 23, 123 will lie in a horizontal plane, as illustrated in Figs. 2 and 3, and thus be below the supply pipe 1. As a consequence, the handle 23,123 if the valve 20, 120 is installed in this manner, is neither visually apparent nor physically accessible. This reverse connection is also unlikely to be used because the "easy hooker" 5 is difficult to connect to the female threaded inlet 21, for example.

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Furthermore, irrespective of which way the valve 20, 120 is connected, thread tape is required.

In accordance with the preferred embodiment, these problems are overcome by use of the generally L-shaped gas isolation valve 30 as illustrated in Figs. 4-11. The valve 30 has an outlet 31, an inlet 32, a handle 33 and a housing 34. Within the housing 34 is a quasi-spherical ball 35 (Fig. 10) which has a hole therethrough which, in known fashion, interconnects the outlet 31 and inlet 32. The ball 35 can be turned by the handle 33 between interconnect and disconnect positions so as to open and close the passage between the inlet 32 and outlet 31.

The outlet 31 takes the form of a male thread 38 which is dimensioned to directly connect with the fitting 7 of the hose 5. The inlet 32 has a loose nut 36 with an interior female thread which mates with the male thread 3 of the gas supply pipe 1. Within the inlet 32 is a metal dome 37 which has an exterior shape which forms a compression seal with the end of the pipe 1. In addition, as best seen in Fig. 10, the metal dome 37 has an interior bore 41.

The regulatory regime which applies to gas connections is Australia/New Zealand Standard AS/NZS 5601.1. This standard sets out in Table 4.1 the standards applicable to pipes, fittings and joining methods for the design, installation and commissioning of gas installations which are to be used with fuel gases such as natural gas, liquefied petroleum gas (LP gas) and biogases such as methane. Table 4.1 requires copper alloy screw fittings to comply with Australia Standard AS 3688. This standard in turn in sets out in Table 3.2 a minimum mean diameter of the passage through which the gas flows as 8.6mm for a nominal size of DN15 (half inch).

This is substantially larger than the traditional internal diameter 7mm of the dome of the fitting 7 of the flexible hose 5. As a consequence, to use the same fitting 7 on the flexible hose 5 for the inlet 32 of the valve 30, would result in the valve 30 not complying with the relevant Australian standards (AS 4617). However, prima facie, any increase in the size of the fitting to accommodate the valve regulations, would

5183BQ-AU 8 result in the enlarged fitting not mating with the male thread 3 of the gas supply pipe 1.

The inventors have been able to overcome this dilemma by increasing only the size of the bore 41, but not increasing the external size of the dome 37. The external diameter of the dome 37 is 17mm and the inventors have determined that the internal diameter of the bore 41 can be in the range of from 8.6mm to 10mm and is preferably 8.6mm.

Furthermore, traditionally prior art valves such as those illustrated in Figs. 2 & 3 have the valve handle adjacent the nut and tail fitting, and the nut and tail fitting is traditionally the outlet of the valve. However, the inventors wish to use the nut and tail fitting for connection to the gas supply pipe 1, thereby obviating the need to use thread tape. In order to permit this to be conveniently done, the inventors have resolved to place the valve handle opposite the nut and tail fitting. This has the desired consequence that the handle is both visually apparent and physically accessible.

Finally, a glance at any plumbing supplier's catalogue, illustrating thousands of products, would seem to indicate that every possible combination of plumbing device has already been manufactured and is offered for sale. However, this is not the case, as no such catalogue product offers the numerous advantages of the present invention. In particular, there is a substantial saving in installation time for the gas fitter in utilising the gas isolation valve of the present invention, an advantage in avoiding the cost of the elbow 15, an advantage in the avoidance of thread sealing tape, an advantage in using a gas certified device, an absence of any sealing gasket, and an enhanced convenience in working in a confined area.

For example, Fig. 11 illustrates in cutaway fashion a typical confined space available for the isolation valve (whether it be the prior art valve 10 or the valve 30 of the preferred embodiment). As seen in Fig. 11, the building has a wall 2 which is covered by a tiled splashback 43 which abuts a kitchen benchtop 44. Underneath the benchtop 44 and illustrated in dashed lines is a cupboard 49. Located on one side wall of the cupboard 49 are an upper track 46 and a lower track 47 which support a drawer 48

5183BQ-AU 9 illustrated in dot dash lines in Fig. 11. On the other side wall of the cupboard 49 are another upper track 46 and lower track 47 all of which are not illustrated in Fig. 11.

Access to the male thread 3 is achieved by removing the drawer 48 so that the gas fitter can reach into the cupboard 49 in order to carry out the necessary installation. In the prior art this involves applying sealing tape to the male thread 3. The next step is connecting the female end of the elbow 15 to the male thread 3 and rotating same to achieve the desired degree of tightness and the correct orientation of the elbow 15. Next sealing tape is applied to the male end of the elbow 15 and the female valve inlet 18 is connected to the elbow 15. At this stage the valve 10 must be rotated to again achieve the desired degree of tightness and the correct orientation of the handle of the valve 10. Finally, the hooker hose 5 is connected to the valve 10 using the fitting 7.

This cumbersome prior art activity carried out in the confined space of the cupboard 49 is to be contrasted with the situation using the valve 30 of Fig. 4 as illustrated in Fig. 12. First of all, no sealing tape is required. The valve inlet 32 is connected directly to the male thread 3 by means of the swivel nut 36. This automatically positions the handle 30 with the desired orientation. It is necessary only to hold the valve 30 in its desired orientation whilst tightening the nut 36 in order to ensure that the outlet of the valve 31 has the desired orientation. Then the hooker hose 5 is directly connected to the threaded male outlet 31 of the valve 30. That is, only two steps and no sealing tape are required.

The foregoing describes only one embodiment of the present invention and modifications, obvious to those skilled in the gas fitting art, can be made thereto without departing from the scope of the present invention.

Furthermore, it should be understood that the present applicants have a very detailed knowledge of the Australian plumbing and gas fitting industries. Accordingly, the reference to prior art valves or fittings referred to herein, does not necessarily mean that other persons in the plumbing industry and gas fitting industry are aware of this prior art, nor does it mean that such prior art is sufficiently well known to constitute common general knowledge in the plumbing industry and gas fitting industry.

5183BQ-AU 10

The term "comprising" (and its grammatical variations) as used herein is used in the inclusive sense of "including" or "having" and not in the exclusive sense of "consisting only of'.

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Claims (1)

1. CLAIMS 1. 1. A gas ball valve comprising a generally L-shaped housing having a quasi-spherical ball having a through hole, a handle mounted on said housing to permit said ball to be rotated between valve open and valve shut positions, and a valve outlet and a valve inlet in communication with said ball, wherein said valve outlet comprises a male thread, said valve inlet comprises a swivel nut and a metal dome, said metal dome having a central bore in communication with said ball, and said handle is located opposite said valve inlet.

   2. The valve as claimed in claim 1 intended to isolate a gas supply to a gas cooker installed in a building, said gas supply comprising a male threaded pipe extending from a wall of said building and said gas cooker having a flexible "easy hooker" style connecting hose terminating in a conventional swivel nut and metal dome connector, said dome connector having a through passage leading to said hose, wherein the size of said central bore exceeds the size of said through passage.

   3. The valve as claimed in claim 2 wherein both said central bore and said through passage are substantially cylindrical and said size constitutes an internal diameter.

   4. The valve as claimed in claim 3 wherein said valve has a size of DN15 (half inch) and said central bore has an internal diameter of at least 8.6 mm.

   5. The valve as claimed in claim 4 wherein said central bore has an internal diameter of between 8.6 mm and 10 mm.

   6. The valve as claimed in any one of claims 1-5 and certified for gas.

   7. The valve as claimed in paragraph 6 and certified to AS 4617.

   5183BQ-AU 12

   8. The valve as claimed in any one of claims 1-7 wherein said metal dome of said valve complies with AS 3688.

   9. A method of installing a gas cooker to connect same to a male thread of a gas supply pipe via a gas isolation valve as claimed in any one of claims 1-8, utilising an "easy hooker" style of flexible hose which terminates in a nut and tail fitting, said method comprising the steps of, in any order: connecting said flexible hose to said threaded valve outlet, and connecting said swivel nut and metal dome to said gas supply pipe male thread without the use of thread tape thereby placing said handle of said valve opposite said gas supply pipe and therefore in a position which is both visually apparent and physically accessible.

   10. The method claim in claim 9 and carried out without the use of sealing tape.

   11. A gas isolation valve installation for a gas cooktop to be supplied with gas via an "easy hooker" style of flexible hose which terminates in a nut and tail fitting, the supply being from a gas supply pipe having a male threaded outlet, wherein said installation comprises a gas isolation valve as claimed in any one of claims 1-8 having said nut and tail fitting of said flexible hose connected to the outlet of said gas isolation valve, and having the swivel nut and dome of said gas isolation valve connected to said gas supply pipe whereby said installation does not utilise sealing tape.

   12. The gas isolation valve installation as claimed in claim 11 wherein said gas supply pipe is located within a cupboard or equivalent kitchen enclosure.

   5183BQ-AU 13

   Dated this 1 1 th day of January 2021

   Zetco Valves Pty Ltd

   By FRASER OLD & SOHN Patent Attorneys for the Applicant

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