WO2022048722A1

WO2022048722A1 - Directional gas leak detector

Info

Publication number: WO2022048722A1
Application number: PCT/DK2021/050271
Authority: WO
Inventors: Lasse JENSEN; Søren Xerxes FRAHM; Tom LUNDQUIST; Peter Billy JACOBSEN
Original assignee: Gasokay Aps
Priority date: 2020-09-04
Filing date: 2021-09-03
Publication date: 2022-03-10

Abstract

A directional gas leak detector for detecting, if there is a gas leak present in a gas system and if so, on which side of the gas leak detector the leak is located. The directional gas leak detector comprises a detector body to be fluidically connected in the gas system, whereby gas can pass through the gas leak detector body between a gas inlet and a gas outlet of the detector body, the detector body having a first and a second chamber with a liquid in them and a gas bridge fluidically connecting the two chambers. If a leak is present in the gas system, bubbles will form in the liquid, as the gas passes through the liquid from the higher-pressure side of the gas system towards the leak.

Description

DIRECTIONAL GAS LEAK DETECTOR

FIELD OF THE INVENTION

The invention relates to the field of gas leak detectors for gas lines. Specifically, it relates to directional gas leak detection and detectors.

BACKGROUND OF THE INVENTION

Gas burners are used for numerous applications including heating and cooking in places, where a steady supply of electricity cannot be ensured for a stove top. This may be for outdoors grilling, on boats out at sea, at cottages far from cities or in areas, where the electricity supply is not steady, and the power may cut frequently. Some people also have a general preference to cooking with gas.

The fact that gas is flammable is what makes it perfect for stove top cooking, but it also poses a danger to the users as leaking of gas causes risks of uncontrolled fire and even explosions, if significant volumes of gas build up. Leaks might happen because of errors in assembly of the gas system, e.g. where a tube is connected to an outlet. Another cause of leaking is the tube itself becoming damaged which can happen because it degrades over time, especially extreme temperatures, sunlight, and ozone can damage the tube, e.g. if it is outdoors in frost or if cooking grease drips on the tube heating it locally. Leaks cause thousands of serious accidents yearly which result in fatalities in the worst cases.

Because of the risks involved, detecting whether leaks are present in the system is essential for using gas safely, e.g. for cooking. Various solutions exist for detecting the presence of leaks in a system. One such solution is to have a manometer integrated with the regulator, but such a solution cannot be retrofitted in a system which makes the solution costly and may discourage users from implementing the necessary safety precautions. Furthermore, some users may not feel comfortable evaluating the readings of a manometer to determine whether the gas system is sufficiently leak-tight. Other solutions such as gas leak bubble detectors solve some of these problems by providing a system that can be retrofitted and is easily evaluated by the user, but these can only show leaks happening between the detector itself and the consumer side, e.g. after the regulator. To monitor the largest possible region of the system, the known bubble detectors must be located as close to the regulator as possible which will unfortunately be as far as possible from where the user will be when working with the gas system, e.g. at a stove top. This means that the user will have to go to where the gas cylinder or tank is located to look at the gas leak detector, as this may be outside the house where it may be cold or dark, or in a small storage compartment on a boat this will make it harder for the user to actually inspect the output of the detector. The more cumbersome it is for the user to use the safety mechanisms, the higher the risk that they will not do it every time, and thus accidents, which could have been avoided, might take place.

SUMMARY OF THE INVENTION

In accordance with the invention, some of the above-mentioned difficulties with gas leak detection will be alleviated by a directional gas leak detector for a gas system comprising:

- a detector body to be fluidically connected in the gas system, whereby gas can pass through the gas leak detector body between a gas inlet and a gas outlet of said detector body,

- the connection body comprising at least a first chamber and a second chamber for holding a liquid, and

- said gas inlet providing a passage to the second chamber and

- said gas outlet providing a passage to the first chamber, wherein the first and second chamber are connected by a gas bridge enabling gas to pass between said chambers via the liquid.

By having at least two chambers in the directional gas leak detector, it becomes possible to detect on which side of the directional gas leak detector a leak is present. When the gas leak detector is installed for use in a gas system, each of the first and second chambers is partially filled with a liquid such as water. If a leak is present in the gas system, the water levels in the two chambers will change due to the differential pressure, and bubbles will form. The bubbles will move in the direction D towards the side, where the leak is. Thus, the bubbles become a clear visual indicator that can be determined by any user without any special training.

By indicating on which side of the gas system the leak is, e.g. the consumption side or the supply side, it becomes easier for the user to locate the problem and deal with it. The leak may be caused by a fault in the connection between a conduit and any of the other components, i.e. the regulator, the burner or the gas supply, and indicating on which side the leak is allows the user to examine only the connections on the relevant side thus making it faster and easier to solve the problem. In the case, where the leak is caused by damage to the conduit, knowing whether it is on the supply side in the supply conduit or on the consumption side in the consumption conduit also allows the user to examine a shorter conduit section to find the leak.

If there is no leak, no bubbles will form, and the user will know that it is safe to proceed with using the gas system.

That the directional gas leak detector makes it possible to determine on which side of the directional gas leak detector itself the leak is located also means that the directional gas leak detector can be placed wherever it is most practical for the user. It may be placed at either end of the gas system, e.g. right before the burner to be as close as possible to where the user is going to be while using the gas system. Alternatively it may be located at the middle to minimise the potential length of conduit to examine, or it may be located at any point along the line where it is easily accessible in the location where the gas system is installed thus making it easy to inspect whether bubbles are formed and how they move. By making the directional gas leak detector easily accessible and more user-friendly, the chances of the leak test being performed frequently is increased which in turn minimises the risk of a leak going undetected and causing an accident.

In an embodiment of the invention, the first chamber comprises a first window of a transparent material, and the second chamber comprises a second window constructed in a transparent material.

Having a window or region of transparent material in the first and second chambers of the directional gas leak detector allows the user to inspect visually what is happening inside the first and second chambers. This is a means for allowing the user to see bubbles moving through the first and/or second chamber, thereby detecting a leak and its position relative to the directional gas leak detector. By a window is understood any region made in a transparent material. In some variants of the invention there may be only a single window in each of the first and second chambers: In another variant, there may be multiple windows, e.g. both in the sides and the bottom of the chambers. In yet another variant, the window may be the full size of the chamber such that all of either or both of the chambers are constructed in a transparent material, e.g. glass or a transparent plastic. In a variant of the invention, the first and second chambers may share a wall separating the two chambers. This wall may also comprise a window.

In an embodiment of the invention, the directional gas leak detector comprises a first back-chamber and a first top opening connecting said first back-chamber to said first chamber, and wherein said directional gas leak detector further comprises a second back-chamber and a second top opening connecting said second back- chamber to said second chamber.

Having a first and second back chamber without any liquid present in addition to the first and second chambers with a liquid at the bottom has the benefit that gas may be led into the first side of the directional gas leak detector, i.e. the side of the first chamber and first back-chamber either from the top or from the bottom of the first back-chamber. Similarly, gas may be led into the second side of the directional gas leak detector, i.e. the side of the second chamber and second back-chamber either from the top or from the bottom of the second back-chamber. In the case, where the there is no first and second back-chambers, it is not possible lead gas in from the bottom as this would lead to the liquid getting into the chamber connector, but as there is no gas in the first and second back-chambers, the gas outlet and the gas inlet can be connected to these from the bottom, respectively. The chamber connectors can also still be located at the top and will not be hindered by the first and second back-chambers.

Being able to locate the gas outlet and the gas inlet freely at the top and/or bottom allows more flexibility in how the directional gas leak detector is located with respect to the gas system. This makes it possible to place it in a manner which is most convenient for the user in a specific location. It may be that it is easier to access the directional gas leak detector, if it is placed above or below the connectors, as it can thus be placed above or below a surface close to the gas system, between closely spaced cupboards, or within other restricted spaces, where it might not have been possible to have the gas outlet and the gas inlet at the gravitational top of the directional gas leak detector.

In an embodiment of the invention, the directional gas leak detector comprises a bypass channel and a test activation means for engaging and disengaging said bypass channel.

A bypass channel allows unobstructed gas flow through the gas system, while the directional gas leak detector is installed. Thus, a bypass channel ensures that the directional gas leak detector may be mounted permanently in the gas system and does not need to be plugged in every time a leak test is made. This makes it much easier and more practical for the user which in turn makes it more likely that a user will make frequent tests thereby increasing the safety of the use of the gas system. In some variants of the invention, the test activation means may be a button or a turn knob that the user can press to begin and/or end a test, i.e. toggle between test mode and bypass mode. In some variants of the invention the test activation means will block the bypass channel and thus force any gas moving in the system to move through the first and second chambers and the gas bridge between them. In another variant of the invention, the test activation means may move the alignment of the directional gas leak detector, such that the gas flows through the chambers and gas bridge rather than through a bypass channel.

In an embodiment of the invention, the directional gas leak detector comprises a pressure lock comprising an activation means for providing a lock-up pressure.

A pressure lock is a means for blocking the flow of gas through the regulator in a gas system temporarily. The pressure lock induces an additional gas pressure into the test volume of the gas system. This brings the regulator into a lock-up mode and will prevent access of gas from the gas supply. By blocking the inflow of gas, the pressure lock ensures that the pressure is the same everywhere between the regulator and the gas consumer of the gas system, if there is no leak in the system. If there is a leak in the system, the pressure lock will still block the flow of gas through the regulator temporarily, but a pressure difference will persist between the sides of the gas system due to the leak. The pressure lock function by introducing an additional volume of gas into the system and thereby increasing the pressure to above the intended output pressure thereby stopping the regulator from introducing more of the supply gas into the system, until the pressure has decreased to the output pressure once more. Thus, the pressure lock requires an activation means that allows the introduction of and compression of gas in the system and thereby increasing the pressure temporarily. The amount of gas introduced in the system and therethrough the rise of the pressure brought on by the pressure lock may vary between different variants of the invention.

The pressure lock allows rapid detection of a leak in the gas system. If no pressure lock is present, the regulator will work to maintain a predetermined output pressure downstream of the regulator. Even when the gas supply is shut off an elevated pressure will remain upstream of the regulator for some time and the regulator will continue to uphold the predetermined output pressure in the gas system. If there is no pressure lock in the gas system, it will not be possible to detect a leak on the supply side of the gas system before the pressure upstream and downstream of the regulator has equalised. Depending on the gas system this may take several minutes and up to half an hour. If there is no leak in the system, the user making the leak test will observe no difference between the situation, where the regulator is ensuring a stable pressure, and when the test is made, showing no leak. Thus, there is a risk of a user not waiting long enough and drawing the wrong conclusion that there is no leak in the system This poses a danger of a false sense of security. Similarly, a longer waiting time in relation to a leak test may mean that the user being in a hurry will sometimes forego making the leak test, thus making the gas system less secure. Hence, implementing a pressure lock, which allows the user to make a rapid leak test, where the results can be seen within less than a minute, increases the security of the system, as the user can be certain that there is no leak, if they observe no bubbles. Furthermore, the user will be more likely to conduct frequent leak tests, when each test does not take long to conduct.

In an embodiment of the invention, the pressure lock is integrated with the test activation means.

By integrating the pressure lock and the test activation, i.e. by introducing the lockup pressure simultaneously with switching from bypass mode to test mode, the number of steps, which the user has to take to make a gas leak test, is reduced and the process simplified, thereby making it more likely that the user makes frequent gas leak tests. In a variant of the invention, the pressure lock is integrated with the test activation means in the form of a piston pump simultaneously applying the lockup pressure and blocking the bypass channel, when the user presses it into position, thereby activating test mode and allowing immediate detection of the presence of leaks.

In an embodiment of the invention, a directional gas leak detector is used with a pressure lock.

The pressure lock needs not be integrated with the directional gas leak detector to obtain the benefits of either. A gas leak detector may be installed in the gas system, where a pressure lock is installed separately. In such a variant of the invention, the directional gas leak detector can be put into test mode, and the pressure lock can be engaged separately still allowing the gas leak detection to take place immediately, after the pressure lock has been engaged. Installing the directional gas leak detector and the pressure lock as separate units in a gas system has the benefit of allowing them to be added to an existing system. For example, if a user has a gas system with a directional gas leak detector already installed, they will not need to replace the directional gas leak detector with one that has an integrated pressure lock, but can retrofit the gas system with a separate pressure lock.

The invention further covers the method of detecting a leak in a gas system comprising

- connecting the described directional gas leak detector to a gas system, and

- ensuring that the gas is not supplied to the directional gas leak detector from a gas supply,

- ensuring there is liquid in a first and second chamber of said directional gas leak detector,

- monitoring whether bubbles form in said liquid,

- determining in which direction bubbles move, if bubbles are formed, thereby determining on which side of said directional gas leak detector a leak is located. In an embodiment of the invention, it is ensured that the gas is not supplied to the directional gas leak detector from the gas supply, as the gas supply is turned off, before the detection of bubbles takes place.

By shutting of the gas supply, no additional gas is supplied to the system, and the pressure upstream and downstream of the regulator is equalised thus allowing any pressure difference due to the presence of a leak to be detected. This variant has the benefit that it requires no special equipment, as gas supplies will typically be made with means for opening and closing the gas supplies, e.g. an opening valve on a gas flask.

In another embodiment of the invention, it is ensured that the gas is not supplied to the directional gas leak detector from the gas supply, as flow from the gas supply is blocked by a lock-up pressure applied by the activation of a pressure lock.

Stopping the flow of gas from the gas supply by supplying a lock-up pressure leads to immediate blocking of the gas supply rather than needing to wait for the equalisation of the pressure upstream and downstream of the regulator. Hence, it allows more rapid detection of a potential gas leak, as the waiting time is decreased.

In an embodiment of the invention, where the directional gas leak detector comprises a bypass channel, the method of detecting a leak includes closing the bypass channel by engaging a test activation means.

By including the bypass channel, the user does not need to reinstall the directional gas detection means in the system, before each gas leak test is made, and they will not need to dismount it from the system, after the test is finished. With the presence of a bypass channel, many tests can be made once the directional gas leak detector has been installed without needing to uninstall it again. Instead, the user simply needs to engage the test activation means to close the bypass channel to begin a test.

In an embodiment of the invention, the test activation means and said pressure lock are activated simultaneously. By engaging the pressure lock and the test activation means simultaneously, the period of time in which a potential leak can be detected is maximised. The pressure lock will hold back the introduction of gas from the gas supply for a limited period of time, and therefore the simultaneous activation ensures that the user does not initiate the leak detection test too late to notice a potential leak. Simultaneous activation also ensures that the user does not need to spend unnecessary time on the test, as there is no need to first activate the test mode by engaging the test activation means to then subsequently activate the pressure lock before observing the results of the leak detection test on the directional gas leak detector. Hence, simultaneous activation of the test activation means and the pressure lock provides an efficient method of performing the gas leak detection.

SHORT LIST OF THE DRAWINGS

In the following, example embodiments are described according to the invention, where

Fig. 1 is a sketch of a gas system with a gas leak detector.

Fig. 2 is a sketch of a regulator shown in a cross-sectional view.

Figs. 3a-3c are schematic drawings of the working principles of a directional gas leak detector in a cut-out of the gas system.

Fig. 4 shows a gas system with a pressure lock.

Figs. 5a-5b show an embodiment of the directional gas leak detector in a compact construction with an integrated bypass and a pressure lock, illustrated in partial cross-sectional view.

Figs. 6a-6c show embodiments of the directional gas leak detector with four chambers and the possibility of having the chamber connectors located above or below the chambers with respect to gravity.

DETAILED DESCRIPTION OF DRAWINGS

In the following, the invention is described in detail through embodiments thereof that should not be thought of as limiting to the scope of the invention. Fig. 1 shows a gas system 1 comprising a gas supply 26, a regulator 50, a supply conduit 24 a directional gas leak detector 100 a consumption conduit 14 and a gas consumer 16.

The fluid used in the gas system 1 , is one which will be a flammable gas at atmospheric pressure, e.g. butane, methane, biogas, propane or mixed gasses. In general, the system may rely on any type of flammable gas which can be transformed from liquid to vapour phase within the ambient temperature and atmospheric pressure, where the gas is being consumed by the end user. The general design of the gas system can be customised for different gasses depending on the properties of the gas and the pressures under which it is stored and used. Commonly, the gas supply 26 is either a central supply distributed to various households through piping structures or a gas cylinder, flask or gas tank closer to the location, where the gas will be consumed. The fuel for the gas system 1 is kept at a supply-pressure P being high enough to keep it in liquid phase thus allowing compact storage. The gas supply 26 may be placed a distance from where the gas is to be used. For instance, the gas supply 26 may be stored away outside a house, in a shed, in a storage compartment on a boat or in the basement near other utilities and will frequently be a distance away from the gas consumer 16. The gas consumer 16 could be a burner on a stove top in a house or on a boat or it might be for a gas grill placed outdoors in a garden. Similarly, the gas system can be used for various applications, where energy consumption is required, such as but not limited to lighting, room heaters, patio heaters, indoor fire pits, soldering, welding and electricity generators. The person using the gas system will usually stay closer to the gas consumer 16 most of the time when operating the gas system 1 than they will to the gas supply 26.

The gas supply 26 may comprise a supply activation 22 which is a means for opening a path for gas to stream from the gas supply 26 and into the rest of the gas system 1 . The supply activation 22 may for example be a valve that the user can open by turning a knob on the gas supply unit 26. Similarly, the gas consumer 16 may comprise a consumption activation 12 which may also be a valve which the user can open by turning a knob. On a gas stove, it may for example have steps indicating how large a stream of gas is allowed through and may in some variants comprise an ignition for igniting the gas at the gas consumer 16. Preferably, a directional gas leak detector 100 is placed between the regulator 50 and the gas consumer 16. In another variant, the directional gas leak detector 100 may be placed between the gas supply 26 and the regulator 50. During use, the directional gas leak detector 100 can indicate on which side of its placement a leak occurs, i.e. on the consumption side 10 from the position of the gas leak detector 100 itself to and including at the connection to the gas consumer 16 or on the supply side 20 between the directional gas leak detector 100 and the regulator 50. Hence, the directional gas leak detector 100 can be placed anywhere between the regulator 50 and the gas consumer 16 thus customising its location to the needs of the user and the restrictions of the environment in which the gas system 1 is placed. This is an advantage over common gas leak detectors of the bubble type which are only capable of detecting leaks on the consumer side 10 and which must thus be placed near the regulator 50 to monitor as much of the gas system 1 as possible.

The regulator 50 is mounted in the gas system 1 near the gas supply 26 and is a means to ensure that the rest of the gas system 1 receives an intended outputpressure p of gas. The distance between the regulator 50 and the gas supply 26 may vary following national regulations, where the gas system is in use. Typically, they will be placed within 1 meter of each other. In the gas supply 26, the fuel is stored under a high supply-pressure P. In embodiments, where the gas supply 26 is a gas cylinder or tank, the supply-pressure P in the gas supply 26 is usually around 0.3-16 bar. In embodiments of the gas system, where the gas is supplied through a pipeline from a central supply, the supply-pressure will commonly be in the range of 20-500 mbar. The output-pressure p of gas intended at the gas consumer 16 will typically be much lower than the supply-pressure P. In many embodiments, the output-pressure at the gas consumer 16 is in the range of 20-500 mbar, i.e. several orders of magnitude lower than the supply-pressure P of a gas cylinder or tank. The regulator 50 ensures that a pre-set output-pressure p is maintained downstream of the regulator 50, when it receives a higher pressure upstream. Depending on the specific application the precision of the pressure output by the regulator 50 may vary.

Fig 2. shows a cross-sectional sketch of a regulator 50 illustrating the concept of a single-stage regulator known in the art. A regulator 50 comprises a regulator inlet 51 to be connected to a high-pressure side. In the gas system 1 (see Fig. 1 ), the regulator inlet 51 is connected to the high-pressure region 30 (see Fig. 1 ), and it receives gas from the gas supply 26 (see Fig. 1 ). A regulator 50 further comprises a regulator outlet 52 which is where the regulator 50 releases gas at a lower pressure then it receives it at the regulator inlet 51 . In the gas system 1 , the regulator outlet 52 is connected to the supply side 20. The regulator inlet 51 and the regulator outlet 52 are connected through a regulator opening 54 which is at least partially blocked by a blocking lever 66. The regulator 50 further comprises a regulator valve which is based on a regulator spring 62, a diaphragm 64 and the blocking lever 66. The diaphragm 64 is connected to the regulator spring 62 on one side and the blocking lever 66 on the other. The length of the blocking lever 66 and the force of the regulator spring 62 are balanced such that the blocking lever 66 blocks the regulator opening 54 partially and only enough gas to uphold the output-pressure p in the regulator outlet 54 is let through the regulator opening 54. If the pressure in the regulator outlet 52 rises above the output-pressure p, the gas will press against the diaphragm 64 and work against the spring force of the regulator spring 62. This will in turn move the blocking lever 64, which is also connected to the diaphragm 66, in such a way that the regulator opening 54 is more closed and less gas can stream through the regulator opening 54, thereby decreasing the pressure in the regulator outlet 52. If the pressure in the regulator outlet 52 is below the output pressure p, the press of the gas on the diaphragm 64 is lessened, and the spring force will move the diaphragm 64 and in turn the blocking lever 66, such that the regulator opening 54 is blocked less, and more gas can stream through to the regulator outlet 54, thereby increasing the pressure. Through this regulator valve, the regulator 50 maintains a steady output pressure p. The uncertainty on the output pressure p depends on the tolerance of the specific regulator, and the properties of the gas and will range from ±5 mbar to ±50 mbar.

Fig. 3a-3c show schematic drawings of the working principle of the directional gas leak detector 100 in different working conditions.

Fig. 3a shows the directional gas leak detector 100 installed in the gas system 1 (see Fig. 1 ), where there is no leak. The gas leak detector 100 comprises a detector body 101 with a first chamber 110 and a second chamber 120 as well as a gas bridge 130. The first 110 and second chambers 120 are joined by the gas bridge 130 that allows the exchange of fluids between the first 110 and second chambers 120. The gas bridge 130 is located below the surface level of the liquid 150 such that there is a liquid connection between the first 110 and second chambers 120, and gas passing between the first 110 and second chambers 120 must pass through the liquid 150 to do so, i.e. the gas bridge is placed low in the directional gas leak detector 100 with respect to gravity. In an embodiment of the invention, the gas bridge 130 connects the bottom half of the first chamber 110 to the bottom half of the second chamber 120, where bottom is considered the lowest point with respect to gravity, i.e. an item affected by gravity will tend to fall from the top towards the bottom, when the directional gas leak detector 100 is installed for use in the gas system 1 (see Fig. 1 ). Furthermore, the directional gas leak detector 100 has a gas outlet 112 for providing a fluidic connection between the first chamber 110 and one side of the gas system 1 , i.e. either the consumption side 10 or the supply side 20 (see Fig. 1 ). The gas outlet 112 may be connected directly to the first chamber 110 or be connected through an additional structure which does not hinder the flow of gas to the first chamber 110. The directional gas leak detector 100 further has a gas inlet 122 for providing a fluidic connection between the second chamber 120 and the other side of the gas system 1 (see Fig. 1 ). The gas inlet 122 may be connected directly to the second chamber 120 or be connected through an additional structure which does not hinder the flow of gas to the second chamber 120. In an embodiment of the invention, the directional gas leak detector 100 is constructed symmetrically such that it does not matter whether the gas inlet 122 or the gas outlet 112, i.e. which connector, faces the side of the gas system 1 , i.e. the consumption side 10 or the supply side 20 (see Fig. 1 ). In other words, the gas inlet can be used as gas outlet and vice versa depending on which way the directional gas detector 100 is installed in the gas system 1 .

The gas outlet 112 and the gas inlet 122 are any means for attaching the directional gas leak detector 100 to the gas system 1 (see Fig. 1 ), e.g. by connecting the detector body 101 to the supply conduit 24 and the consumption conduit 14, respectively. The gas inlet 122 and gas outlet 112 may take any suitable form which may vary for different embodiments suited for mounting in different systems. The connection means of the gas outlet 112 and gas inlet 122 may for example be threaded for connection with another connector piece either on the conduits 14, 24 or for connection directly to the gas consumer 16 or the regulator 50. In other embodiments, the connectors of the gas outlet 112 and the gas inlet 122 may be a nozzle that can be wedged directly into the opening of a conduit 12, 24 in the form of a tube. Various national standards exist for gas system connection means, and the present invention should not be seen as limited to only some connection means, as the working principle of the invention is unaffected by the specific form of the connection means 112,122, and variants adapted to connect with local connection means standards are foreseen. Similarly, the suitable connection means 112,122 may vary depending on the specific type of gas system, i.e. if it is a heating system, a system of cooking, etc. In some embodiments of the invention, the gas outlet 112 and the gas inlet 122 may be of the same type. In other embodiments of the invention, they may be different types of connectors.

When the directional gas leak detector 100 is installed for operation, the first 110 and second chambers 120 are filled partially with a liquid 150. This liquid is what helps visualise any pressure difference in the gas system 1 caused by a leak 90 (see Figs. 3b and 3c). In the case shown in Fig. 3a, there is no leak 90, so the pressures in the consumption conduit 14 and the supply conduit 24 are equivalent, and the liquid levels in the first 110 and second chambers 120 are the same.

Fig. 3b shows the directional gas leak detector 100 installed in the gas system 1 , where there is a leak 90 on the consumption side 10 (see Fig. 1 ) in the consumption conduit 14. When the supply activation 22 is shut off, and the excess pressure built up on the pressure side is equalised with the system, the pressure on the consumption side 10 will remain lower due to the leak 90. In this situation, the output pressure (p) on the supply side 20 (see Fig. 1 ) is higher than the leak pressure (L) on the consumption side 10. This pressure difference leads to a shift in the level of the liquid 150 in the first 110 and second chambers 120 causing the level to be higher in the first chamber 110, i.e. the chamber which is closest to the leak 90 which is in this case the one connected to the consumption conduit 14 on the consumption side 10. Furthermore, bubbles 160 will form, as gas on the supply side 20 (see Fig. 1 ) will move through the consumption conduit 24 towards the leak 90 located on the opposite side on of the directional gas leak detector 100, i.e. the consumption side 10. Hence, the formation of bubbles 160 is a visual indication of the presence of a leak 90, and the direction (D), in which they move, is an indication of the side of the directional gas leak detector 100 on which the leak 90 is located, as the bubbles 160 move towards the leak 90. Hence, the directional gas leak detector 100 can identify the presence of a leak 90 and on which side of the gas system 1 (see Fig. 1 ) it is located, thereby assisting the user in locating the leak and preventing any further leakage of gas.

In Fig. 3c shows the directional gas leak detector 100 installed in the gas system 1 (see Fig. 1 ), where there is a leak 90 in the supply conduit 24 on the supply side 20. When the supply activation 22 (see Fig. 1 ) is shut off and the excess pressure built up on the pressure side is equalised with the system, the pressure on the supply side 20 will stabilise at a leak pressure (L) lower than the output pressure (p) due to the leak 90. In this situation, the output pressure (p) on the consumption side 10 is higher than the leak pressure (L) on the supply side 20 (see Fig. 1 ). This pressure difference leads to a shift in the level of the liquid 90 in the first 110 and second chambers 120, causing the level to be higher in the second chamber 120, i.e. the chamber which is closest to the leak 90 which is in this case on the supply side 20. Furthermore, bubbles 160 will form, as gas on the consumption side 10 will move towards the leak 90 located on the opposite side on of the direction gas leak detector 100, i.e. in the supply conduit 24 of the supply side 20. Hence, the formation of bubbles 160 is a visual indication of the presence of a leak 90, and the direction (D) in which the bubbles 160 move is an indication of the side of the directional gas leak detector 100 on which the leak 90 is located, as the bubbles 160 move towards the leak 90. Hence, the directional gas leak detector 100 can identify the presence of a leak 90 and on which side of the gas system 1 it is located, thereby assisting the user in locating the leak 90 and preventing any further leakage of gas.

If a leak 90 is present on the consumption side 10 of the gas system 1 (see Fig. 1 ), bubbles 160 will be visible immediately in the directional gas leak detector 100. This is the case because the leak pressure L on the consumption side 10 will be lower than the output pressure p on the supply side 20.

If a leak 90 is present on the supply side 20, detecting the leak 90 can only be done once the pressure of the gas system 1 (see Fig. 1 ) has stabilised. Thus, the gas supply 26 (see Fig. 1 ) must be closed off from the rest of the gas system 1 through use of the supply activation 22 (see Fig. 1 ), so that no additional gas is being supplied to the gas system 1. Similarly, the consumer activation 12 (see Fig. 1 ) must be shut off such that the gas system 1 is closed off from the surrounding environment aside from any potential leaks 90. Once the gas system 1 (see Fig. 1 ) is closed off from supply and outlet of gas there will initially be an excess pressure H in the high-pressure region 30 (see Fig. 1 ) of the gas system, i.e. between the gas supply 26 and the regulator 50 (see Fig. 1 ). Initially, this excess pressure H may be around 0.3-16 bars and will thus initially be orders of magnitude larger than the output pressure p. The regulator will continue to let gas through from the high- pressure region 30 (see Fig. 1 ) to the rest of the gas system 1 as long as the excess pressure H in the high-pressure region 30 is larger than the predetermined output pressure p. As the directional gas leak detector 100 relies on the detection of a pressure difference to determine if there is a leak 90 in the gas system 1 , the leak detection will not take place until the excess pressure H has been lowered to the same level as the pressure in the supply conduit 24, i.e. either the output pressure p or the leak pressure L. Thus, a pressure-equalising time T, where the excess pressure H dwindles to the same pressure as the pre-set output pressure p, must take place before a leak 90 on the supply side 20 can be detected. Hence it may take several minutes, e.g. 5-20 minutes, before the directional gas leak detector 100 can provide a reading on whether a leak 90 is present on the supply side 20.

Therefore in a preferred embodiment of the invention, the directional gas leak detector is used with a pressure lock 200 (see Figs. 4 and 5a-5b). The gas system 1 comprising a pressure lock is shown in Fig. 4. The pressure lock 200 is a means of applying a lock-up pressure B to the regulator 50, thereby blocking the flow of gas into the system through the regulator 50, as the pressure exceeds the predetermined output pressure p so that the regulator valve of the regulator 50 closes as the lock-up pressure B moves the diaphragm 64 (see Fig. 2) thus compressing the regulator spring 62 (see Fig. 2) and moving the blocking lever 66 (see Fig. 2) such that the regulator opening 54 (see Fig. 2) is blocked. Thus, by using a pressure lock 200 to introduce a lock-up pressure B, the temporarily increased pressure of the system is the same on the supply side 20 and the consumption side 10, if there is no leak 90 present in the gas system 1 . If there is a leak 90 present in the gas system 1 , the gas will escape through said leak 90 making the pressure lower on that side of the system thus leading to bubbles 160 in the first 110 or second chamber 120 moving in the direction D towards the leak 90.

With the pressure lock 200, the leak detection can take place on both the consumption side 10 and the supply side 20 immediately or at least within a very short time frame of less than a few minutes. As the added gas escapes through a potential leak 90 (see Figs. 3b and 3c), the pressure in the consumption conduit 14 and the supply conduit 24 will decrease, and once the pressure is once more below the predefined output pressure p, the regulator valve will open up the flow of gas through the regulator opening 54 (see Fig. 2), and leak detection can no longer take place. The period of time in which a leak detection can be made on the supply side 20 of the gas system 1 , makes the use of a pressure lock 200 dependant on the extent of lock-up pressure B created by the pressure lock 200, i.e. how big a volume of gas the pressure lock 200 is capable of compressing. It will also depend on the size of the leak 90 (see Figs. 3b and 3c), as a larger opening will allow the gas to escape the gas system 1 at a higher flow rate.

The extent of lock-up pressure (B) applied to the gas system 1 depends on the volume of gas the pressure lock 200 compresses upon activation and the length of the gas system 1 , i.e. how big a volume of gas can be contained within the gas system 1 which depends on the length of the tubing of the supply 24 and consumption conduit 14. In an embodiment of the invention, the pressure lock 200 has a volume of compression of 5-100 ml of gas. Size of the volume of compression for the pressure lock 200 can be varied between embodiments of the invention to be customised for the type of gas and the gas volume of the full gas system 1 , i.e. the lengths and size of tubing in the gas system 1. The gas compression provided by the pressure lock 200 may be varied by the dimensions of the of the pressure lock, e.g. the volume of the pressure lock itself and the travelling distance of the activation means 210 in the case of a piston. In a preferred embodiment, the pressure lock 200 has a volume for compression of 5-25 ml. With a small compression volume in the pressure lock 200, e.g. around 15 ml, the directional gas leak detector 100 will be capable of detecting a leak in a gas system 1 with 1 .5 m of tubing with an inner diameter of 10 mm for approximately a minute. By compressing a larger volume of gas with the pressure lock 200, a longer test time t can be made available.

The pressure lock 200 may compress a volume of gas through any activation means 210. For example, the activation means 210 could be a manual hand-pump for example based on a piston, or it could be an electric pump or a can of compressed gas. In a preferred embodiment, the pressure lock 200 is activated manually through a pressure lock activator 202 such as a button or a turn-knob for opening a valve or the handle or button of a piston system or pump.

Using the pressure lock 200 enables a quick leak detection on either side of the directional gas leak detector 100. Enabling a leak test to be made within a minute allows the user to be sure that they would have noticed bubbles 160 and have detected the leak 90 (see Figs. 3b and 3c), if it is present in the gas system 1 (see Fig. 4). If the user must wait a significant period of time, before receiving a signal indicating a problem, they risk concluding erroneously that there is no leak 90 in the gas system 1 , before the system is ready for the test. Furthermore, the pressure lock 200 enables detection of leaks 90 in the system, while the gas supply 26 has not been turned off on the supply activation 22 (see Fig. 1 ), as the regulator valve is locked effectively regardless of the pressure in the high-pressure region 30 (see Fig. 1 ).

In some gas systems 1 , the pressure lock 200 is mounted separately from the directional gas leak detector 100. In another embodiment, the pressure lock 200 is an integrated part of the directional gas leak detector 100.

Figs. 5a and 5b show a partial cross section of a preferred embodiment of the directional gas leak detector 100. On the side of the second chamber 120, the full structure is shown including a second window 124 which may be made of any transparent material thus allowing the user visual access to the second chamber 120 which is necessary when determining a leak based on the presence of bubbles 160 (see Figs. 3b and 3c) in the liquid 150. The first chamber 110 will also be equipped with a first window 114, but this is not shown in Figs. 5a and 5b, as the first chamber 110 side of the directional gas leak detector 100 is shown in a cross- sectional view to also show the structure above the first chamber 110.

In embodiments of the directional gas leak detector 100, it comprises a bypass channel 140 that allows the gas system 1 to operate normally while the directional gas leak detector 100 is installed in the system. In the structure shown in Figs. 5a and 5b, the bypass channel 140 is an open volume connecting the first 110 and second chambers 120. When the directional gas leak detector 100 is not engaged, the consumption conduit 14 and the supply conduit 24 are connected through the bypass channel 140, and the directional gas leak detector 100 does not influence the gas system 1 . In the embodiment shown in Figs. 5a and 5b, some gas may still enter the first 110 and second chambers 120 through the first test channel 144 and the second test channel 145 (not shown) while bypassing the test system. However, by constructing the bypass channel 140 to be larger than the first 144 and second test channels 145, the bypass channel 140 offers less resistance, and the gas will pass primarily through the directional gas leak detector 100 via the bypass channel 140 as long as it is open.

When a leak test is to be made, the bypass channel 140 is blocked by the test activation means 142, thereby forcing any gas moving between the consumption side 10 and the supply side 20 of the system to move through the first 144 and second 145 test channels into the first 110 and second chambers 120 and pass through the gas bridge 130 between the first 110 and second chambers 120 and hence also through the liquid 15. Thereby, bubbles 160, which can be detected by the user, are created, if there is a pressure difference between the sides of the directional gas leak detector 100 thus causing the gas to move across said directional gas leak detector 100.

When a leak test is to be made, the test activation means 142 is engaged, and the bypass channel 140 is closed, whereby the gas is directed through the first 110 and second chamber 120 and the gas bridge 130 between them. In an embodiment of the invention the test activation means 142 must be engaged by the user throughout the span of the test, e.g. being a button that is held down during the test or a mechanism that is rotated and held in place. In another embodiment of the invention, the test activation means 142 can be locked in place, so that the user does not need to apply any force to it during the test itself. In such an embodiment, where the test activation means 142 can be locked in place, the user will have to release the test activation means 142 manually, once the test is done, and bypass mode is once more desired.

In a preferred embodiment of the invention illustrated in Figs. 5a and 5b, the pressure lock 200 is integrated in the directional gas detector 100. In this embodiment, the test activation means 142, the pressure lock activator 202, and the activation means 210 are all combined in one part taking the form of a small piston pump which introduces air from the surroundings into the gas system, thereby creating the lock-up pressure B. At the same time, the piston of the pump functions as a test activation means 142, as the structure blocks the bypass channel 140, once it has been pressed to create the lock-up pressure B. This integrated solution allows a compact construction, where the user needs only interact with a single unit to make a leak test, thereby simplifying the process and making it easy to perform a test in relation to every use of the gas system 1 (see Fig. 4).

Fig. 5a shows the compact embodiment of the directional gas leak detector 100 in bypass-mode, where the bypass channel 140 is open, before the combined test activation means 142 and the pressure lock 200 have been engaged by the user. Assuming that the directional gas leak detector 100 is mounted in the system such that the gas inlet 122 is connected to the supply conduit 24 and the gas outlet 112 is connected to the consumption conduit 14 (see Figs. 3a-3c), the gas will in bypass mode enter the directional gas leak detector 100 through the gas inlet 122 and pass directly through the bypass channel 140 and out through the gas outlet 112. The directional gas leak detector 100 may be installed oppositely such that the gas outlet 112 is connected to the supply conduit and will in that case function in the same manner.

Fig. 5b illustrates the situation, where a test-mode has been engaged, and the bypass channel 140 is blocked by the test activation means 142. If there is a leak 90 on the consumption side 10, gas will move from the supply side 20 (see Fig. 4) towards the leak 90. Thus, in test mode, the gas will enter the directional gas leak detector 100 through the gas inlet 122 and move towards the bypass channel 140, but as the bypass channel 140 is blocked, the gas will move through the second test channel 145 (not shown) into the second chamber 120 and through the gas bridge 130 into the first chamber 110. It is this movement of gas through the second 120 and first chambers 110 which will cause bubbles 160 to form and move through the liquid 150. The gas will exit the first chamber 110 through the first test channel 144 and continue out of the directional gas leak detector 100 through the gas outlet 112, wherefrom it can move out of the system through the leak 90 placed on the consumption side 10.

In a preferred embodiment of the invention, the test activation means 142 is integrated with the activation means 210 of a pressure lock 200 such that a lock-up pressure B is created in the system, and detection of a leak takes place immediately. In another embodiment of the invention, the directional gas leak detector 100 is equipped with a bypass channel separate from a potential pressure lock 200 rather than them being integrated. The bypass channel 140 and test activation means 142 may be made similar to what is illustrated in Figs. 5a and 5b, where the activation means 142 is only made as a block of the bypass channel 140 without comprising any activation means 210. In other embodiments of the invention, the test activation means 142 may take another form than the closing cylinder and may for example be a disc or a lid slid in place to close the bypass channel 140.

Figs. 6a-cb show preferred embodiments of the invention in which the directional gas leak detector 100 comprises a first chamber 110 and a first back-chamber 116, a second chamber 120 and a second back-chamber 126. While the first 110 and second chambers 120 contain the liquid 150, in which bubbles 160 can form, the first 116 and second back-chambers 126 contain no liquid, but is each a space, where the gas can be contained.

Fig. 6a illustrates the concept of the four chambers without the remainder of the directional gas leak detector 100, i.e. without chamber connectors of the gas inlet and gas outlet or outer wall thicknesses. It is shown in a semi-transparent perspective, where some lines in the background are dashed for easier distinction of the layers of the structure.

As in all other embodiments of the invention, the first 110 and second chambers 120 are fluidically connected only through the gas bridge 130 which is located below the surface of the liquid 150 in the first 110 and second chambers 120, respectively, i.e. the gas bridge is located low in the directional gas detector 100 with respect to gravity. Meanwhile the first chamber 110 is connected to the first back-chamber 116 through a first top opening 118, and the second chamber 120 is connected to the second back-chamber 126 through a second top opening 128. The top opening may be a gap above a first 117 and second back-chamber wall 127 as illustrated in Fig. 6a or it may be an opening or channel through the first 117 and second back- chamber wall 127, respectively. The first 118 and second top openings 128 need not be made in the same manner as long as they allow gas communicating between the first chamber 110 and first back-chamber 116 and the second chamber 120 and second back-chamber 126, respectively. In another embodiment of the invention, the first chamber 110 does not need to share a wall with the first back-chamber 116 The chambers may be disconnected aside from through the top opening 118. The same is the case for the second chamber 120 and the second back-chamber 126. The first 118 and second top openings 128 are located gravitationally higher than the gas bridge 130, and the surface level of the liquid 150 is in both the first 110 and second chambers 120 above the gas bridge 130 and below the first 118 and second top openings 128, respectively. This ensures that gas can pass directly between the first back-chamber 116 and the first chamber 110 and between the second back- chamber 126 and the second chamber 120, respectively, but for gas to pass between the first 110 and second chambers 120, it has to pass through the liquid 150 to go through the gas bridge 130. The first back-chamber 116 and the second back-chambers 126 have no direct connection. This configuration of four chambers ensures that the liquid can be placed at the gravitational bottom of the first 110 and second chambers 120, while the gas outlet 112 and the gas inlet 122 may be located either at the gravitational top or gravitational bottom of the directional gas detector

100 and be connected to the gas system 1. This flexibility in the placement of the gas outlet 112 and the gas inlet 122 allows versatility in the installation of the directional gas leak detector 100 in a gas system 1 which is important, when it needs to be installed in a place with limited space, e.g. above or below the surface of a table or between cabinets. Ensuring that the directional gas leak detector 100 takes up little space and is easily accessible for the user increases the chance of it being installed and frequently used and thus also the safety that it provides.

In some embodiments of the invention, the directional gas leak detector 100 comprises connection means that allows a connection unit 103 comprising the gas outlet 112 and the gas inlet 122 to be releasably connected to a detector body 101 comprising the first 110 and second chambers 120 as well as the first 116 and second back-chambers 126. The detector body 101 comprises connection means such as threading or snap-fit at both the top and bottom such that the connection unit 103 may be connected to the detector body 101 at either the top or bottom depending on what is preferable for the particular gas system in which the directional gas detector 101 is installed. Furthermore, in such embodiments, the detector body

101 comprises apertures in both the top and bottom for the gas outlet 112 and the gas inlet 122 to interface with and which allow gas into the detector body 101 , once it is connected to the gas system 1. In these embodiments, the directional gas leak detector 100 further comprises a cap unit 105 which can be releasably connected to the opposite end of the detector body 101 with respect to the connection unit 103. This cap unit 105 ensures that the directional gas leak detector 100 is leak-tight when connected to the gas system 1 by blocking the apertures not engaged by the gas outlet 112 and the gas inlet 122.

Fig. 6b illustrates an embodiment of the directional gas leak detector 100, where the gas outlet 112 and the gas inlet 122 are placed above the first 110 and second chambers 120. This embodiment of the invention functions like the previously described embodiment. The gas outlet 112 connects one side of the gas system 1 to the first chamber 110 through a first top aperture 119 wherefrom it can also enter the first back-chamber 116 through the first top opening 118. Similarly, the gas inlet

122 connects the other side of the gas system 1 to the second chamber 120 through a second top aperture 129 wherefrom it can enter the second back-chamber 126 through the second top opening 128. Gas may be exchanged between the first 110 and second chamber 120 through the gas bridge 130 by passing through the liquid 150. Thereby, the movement of gas in the form of bubbles 160 reveal the presence of a pressure difference between the sides of the system and hence the presence of a leak 90. In a preferred embodiment, the first 118 and second top opening 128 are larger than the gas bridge 130. The directional gas leak detector 100 further comprises a cap unit 105 which blocks the first 113 and second bottom apertures

123 ensuring that the directional gas leak detector 100 does not leak through the apertures which are not connected to the gas outlet 112 and the gas inlet 122.

Fig. 6c illustrates an embodiment of the directional gas leak detector 100, where the gas outlet 112 and the gas inlet 122 are placed below the first 110 and second chamber 120. In this case, the gas outlet 112 connects one side of the gas system 1 to the first back-chamber 116 and through that to the first chamber 110. Similarly, the gas inlet 122 connects the other side of the gas system 1 to the second back- chamber 126 and through that the second chamber 120. As the liquid 150 is pulled by gravity to the bottom of the first 110 and second chambers 120, respectively, the gas outlet 112 and the gas inlet 122 cannot connect directly to the bottom of the first 110 and second chambers 120, or the liquid 150 would be able to pass into the gas outlet 112 and the gas inlet 122. By connecting the gas outlet 112 to the bottom of the first back-chamber 116 instead, the gas will still have access to the first chamber 110, as it passes through the first top opening 118 unhindered and will still have to pass through the liquid 150 to move from the first chamber 110 to the second chamber 120. The same is the case for the gas inlet 122 which connects to the bottom of the second back-chamber 126 and through the second top opening 128 to the second chamber 120. Gas entering the second chamber 120 from the gas inlet 122 can thus only pass from the second chamber 120 to the first chamber 110 by passing through the liquid 150 thus making movement of gas in the form of bubbles 160 visible. Hence, the first 116 and second back-chambers 126 allow the placement of the gas outlet 112 and the gas inlet 122 at the bottom of the directional gas leak detector 100 without risking liquid 150 leaking into the gas system 1 or the liquid not covering the gas bridge 130.

The variant of the directional gas leak detector 100 with four chambers may be used in combination with any of the other features if the embodiment with two chambers. It may be used with a pressure lock 200 or be integrated with a pressure lock 200. The directional gas leak detector 100 with four chambers may have an integrated bypass channel 140 and test activation means 140. Similarly, the directional gas leak detector 100 with four chambers may be integrated with a pressure lock 200 and a bypass channel sharing pressure lock activator 202 and test activation means 142.

Claims

25 CLAIMS

1 . A directional gas leak detector (100) for a gas system (1 ) comprising:

- a detector body (101 ) to be fluidically connected in said gas system (1 ), whereby gas can pass through said gas leak detector body (101 ) between a gas inlet (122) and a gas outlet (112) of said detector body (101 ),

- said connection body (101 ) comprising at least a first chamber (110) and a second chamber (120) for holding a liquid, and

- said gas inlet (122) providing a passage to said second chamber (110) and

- said gas outlet (112) providing a passage to said first chamber (120), wherein said first (110) and second chambers (120) are connected by a gas bridge (130) enabling gas to pass between said chambers (110,120) via said liquid (150).

2. A directional gas leak detector according to claim 1 , wherein said first chamber (110) comprises a first window (114) of a transparent material, and said second chamber (120) comprises a second window (124) constructed in a transparent material.

3. A directional gas leak detector according to any of the previous claims, wherein said directional gas leak detector (100) comprises a first back-chamber (116) and a first top opening (118) connecting said first back-chamber (116) to said first chamber (110), and wherein said directional gas leak detector (100) further comprises a second back-chamber (126) and a second top opening (128) connecting said second back-chamber (126) to said second chamber (120).

4. A directional gas leak detector according to any of the previous claims, wherein said directional gas leak detector (100) comprises a bypass channel (140) and a test activation means (142) for engaging and disengaging said bypass channel (140).

5. A directional gas leak detector according to any of the previous claims, wherein said directional gas leak detector (100) comprises a pressure lock (200) comprising an activation means for providing a lock-up pressure (B).

6. A directional gas leak detector according to claim 5, wherein said pressure lock (200) is integrated with said test activation means (142).

7. A directional gas leak detector according to claims 1-4 for use with a pressure lock (200).

8. A method of detecting a leak (90) in a gas system (1 ) comprising:

- connecting a directional gas leak detector (100) according to claim 1 to a gas system (1 ), and

- ensuring that the gas is not supplied to the directional gas leak detector (100) from a gas supply (26),

- ensuring there is liquid (150) in a first (110) and second chamber (120) of said directional gas leak detector (100),

- monitoring whether bubbles (160) form in said liquid (150),

- determining in which direction bubbles (160) move, if bubbles (160) are formed, thereby determining on which side (10,20) of said directional gas leak detector (100) a leak (90) is located.

9. A method of detecting a leak (90) in a gas system (19) according to claim 8, wherein the gas supply (26) is turned off before the detection of bubbles (160) takes place.

10. A method of detecting a leak (90) in a gas system (19) according to claim 8, wherein the flow of gas from the gas supply (26) is blocked by a lock-up pressure (B) applied by the activation of a pressure lock (200).

11 . A method of detecting a leak (90) in a gas system (19) according to any of the claims 8-10, wherein a bypass channel (140) is closed by engaging a test activation means (142).

12. A method of detecting a leak (90) in a gas system (19) according to claim 11 , wherein said test activation means (142) and said pressure lock are simultaneously activated.