FIELD OF INVENTION

This invention relates to plumbing. More specifically, it relates to a method of controlling plumbing fixtures or installations. In particular, the invention relates to a method of controlling fluid flow through these plumbing fixtures.

BACKGROUND OF INVENTION

In some parts of the world, and particularly so in South Africa, water is a very scarce, valuable resource. Despite this, wasteful water consumption, particularly in public settings, is a real problem. In shared-use establishments such as communal establishments, residential property, guest houses and hotels, misuse of available warm water, for example, by one user could result in scarcity thereof for the other remaining users. Electricity has also become expensive and unreliable. Warm water is therefore a combination of two scarce resources namely water and electricity. To address this problem, smart water shut-off systems have been developed to limit water usage in general, or per user. Some of these systems have the ability to warn the user that a prescribed usage limit is fast approaching, and continued consumption may result in water supply interruption.

These water shut-off systems make use of audible or visual indicators to warn a user that water shut-off is imminent. However, there are certain drawbacks associated with these systems. Firstly, installation of visual or audible warning devices is cumbersome and labour intensive, especially taking into account that water outlets are usually distributed across different parts of a home or building. This may require installation of several different visual and/or audio warning devices. Furthermore, bathroom conditions are tough on electronic devices and hence reliability is a concern in a bathroom setting. Finally, these warning devices may not be aesthetically pleasing and may even be a cause of irritation, in the case of an audible warning system.

The present invention aims to alleviate the drawbacks discussed above.

SUMMARY OF INVENTION

In accordance with a first aspect of the invention, there is provided a method of controlling a valve assembly, which valve assembly is configurable between an open state, a closed state and a warning state in order to control fluid flow through the valve assembly, wherein: when in its open state, unrestricted fluid flow through the valve assembly is permitted; when in its closed state, fluid is not permitted to flow through the valve assembly; and when in its warning state, fluid flow through the valve assembly is impeded, at least temporarily, the valve assembly including: a control unit; a flow sensor which is communicatively coupled to the control unit and is configured to detect flow of fluid through the valve assembly; and a valve actuator which is operatively connected to a valve and wherein the control unit is configured to control actuation of the valve actuator to move the valve into an open position when the valve assembly is in the open state, to a closed position when the valve assembly is in the closed state and to actuate the valve to a perform a warning action when the valve assembly is in the warning state, the method including: with the valve assembly in its open state, sensing, using the flow sensor, fluid flow through the valve assembly and communicating this to the control unit; determining, using the control unit, whether a predetermined first flow criterion has been satisfied; and provided that the predetermined first flow criterion has been met, changing the state of the valve assembly to the warning state and actuating, using the valve actuator, the valve to perform the warning action resulting in temporarily impeded fluid flow through the valve assembly.

Actuating the valve to perform the warning action may include temporarily altering the position of the valve by actuating the valve actuator. Actuating the valve to perform the warning action may include temporarily restricting fluid flow through the valve assembly by at least partially closing the valve. Actuating the valve to perform the warning action may include, in short successive intervals, closing and opening the valve using the valve actuator. Furthermore, actuating the valve to perform the warning action may include at least partially closing and opening the valve. Also, actuating the valve to perform the warning action may include modulating actuation of the valve actuator in order to vary the position of the valve thereby altering fluid flow temporarily for short succeeding intervals.

The predetermined first flow criterion may be a predetermined length of time for which the valve assembly is in its open state. Alternatively, the predetermined first flow criterion may be a predetermined volume of fluid which has passed through the valve assembly.

The method may include, with the valve assembly in the warning state, determining, using the control unit, whether a predetermined second flow criterion has been satisfied; and provided that the predetermined second flow criterion has been satisfied, changing the state of the valve assembly to closed. The method may include, with the valve assembly in either of its open or warning states, sensing, using the flow sensor, that fluid flow through the valve assembly has stopped, and changing the state of the valve assembly to a paused state.

The valve actuator may be a motorised valve actuator.

The method may include detecting, using the flow sensor, whether a tap has been left open following closure of the valve assembly by: opening the valve assembly for a specific period of time to account for water refilling piping downstream of the valve assembly, and only thereafter detecting, using the flow sensor, fluid flow and reverting to the closed state of the valve assembly should fluid flow be detected.

The invention extends to a computer-readable storage medium having program instructions stored thereon, which, when executed by a computing device of a valve assembly enable the valve assembly to perform any of the method steps described above.

In accordance with another aspect of the invention, there is provided a valve assembly which is configurable between an open state, a closed state and a warning state in order to control fluid flow through the valve assembly, wherein: when in its open state, unrestricted fluid flow through the valve assembly is permitted; when in its closed state, fluid is not permitted to flow through the valve assembly; and when in its warning state, fluid flow through the valve assembly is impeded, at least temporarily, the valve assembly including: a control unit; a flow sensor which is communicatively coupled to the control unit and is configured to detect flow of fluid through the valve assembly; and a valve actuator which is operatively connected to a valve and wherein the control unit is configured to control actuation of the valve actuator to move the valve into an open position when the valve assembly is in the open state, to a closed position when the valve assembly is in the closed state and to actuate the valve to a perform a warning action when the valve assembly is in the warning state.

The valve assembly may further be configured to: with the valve assembly in its open state, sense, using the flow sensor, fluid flow through the valve assembly and communicate this to the control unit; determine, using the control unit, whether a predetermined first flow criterion has been satisfied; and provided that the predetermined first flow criterion has been met, change the state of the valve assembly to the warning state and actuate, using the valve actuator, the valve to perform the warning action resulting in temporarily impeded fluid flow through the valve assembly.

The valve assembly may be configured to perform any one of the method steps described above. The valve assembly may be configured for connection to a fluid line, in inline fashion. The valve assembly may include an energy harvesting fluid flow sensor which is configured to charge a backup battery when fluid flows through the valve assembly. The valve assembly may also include a temperature sensor to measure temperature of the fluid. The temperature sensor may be configured directly or indirectly to measure the temperature of the fluid. The valve assembly may be configured to report the measured temperature to a user.

The invention also extends to a system which includes: at least two valve assemblies as described above which are daisy chained together, each valve assembly being connected in inline fashion to a separate fluid line; and a base station which is communicatively linked to one of the valve assemblies and to a remote device for communicating status and control information to/from the remote device.

Performing the warning action may include pulsing, using the control unit, the valve actuator in order temporarily to close the valve for short succeeding intervals.

The valve actuator and valve may be integrated into a single compact unit. The control unit may also be integrated into the single compact unit. The fluid may be water.

BRIEF DESCRIPTION OF DRAWINGS The invention will now be further described, by way of example, with reference to the accompanying schematic drawings.

In the drawings:

Figure 1 shows a three-dimensional view of a valve assembly in accordance with the invention;

Figure 2 shows a functional block diagram of the valve assembly of Figure 1 ;

Figure 3 shows a flow diagram of a method of controlling the valve assembly, in accordance with another aspect of the invention;

Figures 4A and 4B illustrate block diagrams of two separate embodiments of a system in accordance with yet another aspect of the invention; and

Figure 5 illustrates a timing diagram of operation of the valve assembly.

DETAILED DESCRIPTION OF AN EXAMPLE EMBODIMENT

The following description of the invention is provided as an enabling teaching of the invention. Those skilled in the relevant art will recognise that many changes can be made to the embodiments described, while still attaining the beneficial results of the present invention. It will also be apparent that some of the desired benefits of the present invention can be attained by selecting some of the features of the present invention without utilising other features. Accordingly, those skilled in the art will recognise that modifications and adaptations to the present invention are possible and can even be desirable in certain circumstances, and are a part of the present invention. Thus, the following description is provided as illustrative of the principles of the present invention and not a limitation thereof.

In the Figures, reference numeral 10 refers generally to a valve assembly in accordance with the invention. The valve assembly 10 is used for controlling flow of water through a conduit based on one or more fluid flow criteria. In this example embodiment of the invention, the valve assembly 10 is configured for inline connection to a warm water supply line (not shown). It will be appreciated that the scope of protection of the valve assembly 10 is not limited to this example embodiment and, accordingly, it may also be connected to a mains supply line. Alternatively, the valve assembly 10 may be connected to individual lines to control flow of these lines in isolation.

To facilitate inline coupling to these lines, the valve assembly 10 includes a compression fitting or coupling 11 toward each end thereof which renders the valve assembly 10 easily connectable to the water supply line. The valve assembly 10 also includes an electronically/electrically actuated valve and a flow sensor 14 which are connected in fluid flow communication to one another. In this example embodiment the electronically actuated valve takes the form of a motorised valve 12. Other types of valves such as solenoid valves (not shown) may also be used instead of the motorised valve 12. There are different pros/cons associated with the use of each valve type. The flow sensor 14 is configured to detect the presence of, and measure the flow of, water through the valve assembly 10. The flow sensor 14 is operatively connected in fluid flow communication with the motorised valve 12, downstream thereof. As illustrated in Figure 1 , water flows through the valve assembly 10 in the direction of arrows X. The flow sensor 14 may also be arranged upstream of the motorised valve 12. The valve assembly may also include a temperature sensor (not shown). The temperature sensor may be configured directly or indirectly to measure the temperature of the water passing through the valve assembly.

With reference to Figure 2, the motorised valve 12 includes a motorised valve actuator 12.1 which is drivingly coupled to a valve 12.2 which is movable between open and closed positions in conventional fashion. As is commonplace, the valve 12.2 includes a valve casing which defines a valve seat (not shown) for receiving a valve member (not shown). The valve 12.2 may take the form of a ball valve. That said, there are numerous other types of valves that would also be suitable for use with the valve assembly 10. The motorised valve 12 in this example embodiment has a housing 13 which is configured to house other electronic/electrical components forming part of the valve assembly 10 as a whole. In order to control actuation of the motorised valve 12, the valve assembly 10 further includes a control unit 15, which may include a microcontroller, which is operatively also housed within the housing 13. The control unit 15 controls operation of the valve assembly 10 and, to this end, is communicatively coupled to the motorised valve 12 and is configured to control actuation of the motorised valve 12. In addition, the flow sensor 14 is also communicatively coupled to the control unit 15. The valve assembly 10 further includes a power supply 16 which supplies the components, i.e., the control unit 15, flow sensor 14 and motorised valve 12 with power. The power supply 16 may be a mains power connection. Alternatively, or in addition, the power supply 16 may include backup battery power. The power supply 16 may also include a solar power converter. The valve assembly 10 further includes a wireless communication module 17 which is configured to communicate with a remote device 18. The communication module 17 is also communicatively coupled to the control unit 15. The remote device 18 may be an owner’s mobile phone.

The motorised valve 12 further includes a manual override wheel 20 (see Figure 1 ). The manual override wheel 20 is mounted to a top of the housing 13. Through use of the override wheel 20, a user can manually manipulate the position of the valve member. This may become necessary should electronic control of the valve 12.2 fail or malfunction e.g. due to complete power failure/disconnection or failure of other essential parts driving valve member movement. A transparent inspection window or valve position indicator 22 is provided in the top of the housing 13. The inspection window 22 allows one to see in which position the valve member is.

The valve assembly 10 in accordance with the invention is configurable between an open state, a closed state and a warning state. The state of the valve assembly 10 determines fluid flow therethrough. In other words, when in its open state, unrestricted fluid flow through the valve assembly is permitted. When in its closed state, fluid is not permitted to flow through the valve assembly 10 and, when in its warning state, fluid flow through the valve assembly 10 is impeded, at least temporarily.

Accordingly, the control unit 15 is configured to control actuation of the motorised valve actuator 12.1 to move the valve 12.2 into an open position when the valve assembly 10 is in its open state and to a closed position when the valve assembly 10 is in the closed state. Also, provided a predetermined first flow criterion T1 (see Figure 5) has been satisfied, the control unit 15 is configured to actuate the valve 12.2 to a perform a warning action when the valve assembly 10 is in the warning state. Performing the warning action includes temporarily actuating the valve actuator 12.1 to alter a position of the valve 12.2 thereby temporarily restricting fluid flow through the valve assembly 10. This is achieved by at least partially closing the valve 12.2. Furthermore, performing the warning action may include, in short successive intervals, closing and opening the valve 12.2 using the valve actuator 12.1. Performing the warning action may include at least partially closing and opening the valve 12.2. To this end, performing the warning action may include pulsing, using the control unit 15, the valve actuator 12.1 in order temporarily to close and open the valve 12.2 for short succeeding intervals.

In Figure 3, reference numeral 30 generally indicates a method of controlling the valve assembly 10 in accordance with another aspect of the invention. The method 30 aims to control water usage, e.g., hot water usage, so that, should a user exceed usage limits (Ttotal in Figure 5), determined based on either duration of use or volume of water used, the valve 12.2 is temporarily closed to interrupt water supply and prevent overuse. However, as alluded to above, the valve assembly 10 is characterized in that it is configured to warn the user that the predefined usage limits are approaching by momentarily restricting water flow by at least partially closing the valve 12.2. The resultant change in water flow or water temperature through the valve assembly 10 must be sufficient to be noticeable by the user, otherwise it would not serve as a warning that the usage limits are drawing near, and water interruption is imminent. Under normal operating conditions, the valve assembly 10 is in its open state 31 with the valve 12.2 in its open position 32. With the valve assembly 10 in this condition, a user can open a hot water tap to shower and start using water. The method 30 includes sensing 33, using the flow sensor 14, fluid flow through the valve assembly 10 and communicating this to the control unit 15. It will be understood that water usage limits are user-selectable and can be entered/selected via a purpose-built mobile application or via a purpose-built keypad and display unit 54 (see Figure 4B). When the user sets usage limits via the application, these limits are downloaded to the valve assembly 10 via the communication module 17, or in the case of Figures 4A via a base station 9. The usage limits can be based on a specific period of time T1 during which the valve is open before the warning state is entered and then a further second period of time T2 during which the valve remains open whilst in the warning state before the valve is ultimately closed after expiry of Ttotal, at least temporarily. Alternatively, instead of monitoring time periods, the usage limits can be set based upon a volume of water used as measured by the flow sensor 14.

Therefore, using the mobile application, a user selects the first flow criterion being a cumulative length of time T1 during which the valve is open before the WARNING state is entered. The user also selects the second flow criterion being the length of time T2 during which the valve is open whilst in the warning state before closure. If any of these flow criteria are exceeded, the state of the valve assembly is updated/changed in accordance with the flow diagram illustrated in Figure 3. The user may also choose a total time (Ttotal) and then T1 and T2 are calculated with T1 being 75% into Ttotal.

The method 30 therefore includes determining 34, using the flow sensor 14, when flow is interrupted, i.e., water flow stops. Should this happen, the valve assembly 10 enters a paused state, which, for example, may be due the user closing the tap whilst showering. Should this persist for an uninterrupted period of time T4 which is longer than a reset threshold period 35, the method 30 restarts and a water usage counter/timer is reset. The water usage timer/counter is cumulative until the first flow criterion T1 is exceeded, or the usage counter is reset as described above through non-use for longer than the reset threshold period T4. Once the cumulative water usage time exceeds the first flow criterion T1 at 36, the valve assembly 10 enters the WARNING state 37. Once in the WARNING state, the control unit 15 actuates the valve actuator 12.1 to perform the warning action 38 as described above to make the user aware that a first usage limit has been exceeded. A second water usage timer/counter is then initiated to measure water usage whilst in the warning state which is then compared to the second flow criterion T2. Performance of the warning action 38 results in temporarily impeded or restricted water flow through the valve assembly 10 which is perceivable by the user.

The method 30 further includes sensing 40 water flow whilst in the warning state to determine whether or not the second flow criterion T2 has been exceeded 43. Again, if water flow is interrupted 41 for greater than the reset threshold period T4 at 42, the water usage counter is reset and the valve assembly 10 is returned to its open state 31. However, should cumulative water usage in the warning state exceed at 43 the second flow criterion T2 as determined by the flow sensor 14 and control unit 15, the state of the valve assembly 10 is changed to CLOSED 44 and the valve is closed 45. Once in the CLOSED state, the valve remains closed, thus preventing further water usage, for a pre-set “on-hold” period of time T3 at 46 before the valve assembly 10 is automatically reset and ready to open the valve again.

An important feature of the valve assembly 10 is that it is configured to detect, if, for instance, the hot water tap has been left open after the valve assembly 10 entered the CLOSED state 44, or if subsequently a significant leak has developed in the plumbing system. At the end of the “on-hold” period T3, prior to the valve assembly reverting back to its OPEN state 31 , the valve assembly 10 is opened at 48 for a specific period of time T5 to account for water to refill the piping downstream of the valve assembly 10. Thereafter, if flow is still detected 49 by the flow sensor 14, the control unit 15 assumes that the tap downstream of the valve has been left open or a leak has developed in the system and the control unit 15 will then close the valve 45 and revert to its CLOSED state, i.e. the start of the T3 “on-hold” period in Figure 5. This prevents a tap that was left open, or a leak, to result in water flow for an indefinite period. A system configuration with for instance a Wi-Fi connection can be set up to send a push notification to the user should this condition be detected. Should the flow sensor 14 not detect flow at 49, the valve assembly 10 returns to its OPEN state 31 .

The communication module 17 may be configured for Wi-Fi connectivity or any other suitable wireless communication protocol such as cellular or LoRaWAN. This provides the valve assembly 10 with access the internet or other wireless networks. Wireless connectivity via the communication module 17 enables remote monitoring of the valve assembly 10 to be performed. A user may therefore, via the mobile application, be able to monitor health of the valve assembly, water consumption, amongst other statistics and may be able to open/close the valve remotely. The backup battery allows continued operation of the valve assembly for a limited period of time during power failures. When battery power becomes critically low, the control unit 15 sets the valve to a default condition (open or closed) and powers down. When power is restored, the valve assembly resumes normal operation. Different operating parameters may be specified by the owner for different times of the day or day of the week. Furthermore, management of the valve assembly’s operating parameters differentiates between a user with “administrator” rights, who enjoys full control, and those with “user” rights who have access but limited privileges. For example, a user with “administrator” rights may have the option via the mobile application to reset the unit from the CLOSED state to the OPEN state. The administrator may also have the option to maintain the unit in the CLOSED or OPEN state, either indefinitely or for a specified duration. The mobile application is the primary interface between the owner and the valve assembly. Software updates to the assembly can be performed “over-the-air” by means of the communication module 17 without inconvenience to the user. In case the assembly becomes non-operational, the manual override wheel 20 is available to manually adjust the valve to the open or closed position. In addition, the valve assembly 10 has a built-in test function that allows it to default to the open position in case of a condition that it cannot recover from, for instance, no external power and a low battery condition. The valve assembly will resume normal operation if the conditions return to normal.

It is important to note that the valve assembly 10 makes provision for a PAUSE state. This caters for the scenario of interrupted water use. For example, a person taking a shower may close the tap to apply soap, and may then open it again to rinse. When this happens the water usage timer is paused so that the time of the interruption is not deducted from the total time (Ttotal) allowed.

Reference is now made to Figure 4A which illustrates a first embodiment of a system 50.1 which includes at least one, but preferably two or more, valve assemblies 10 stringed together in linear fashion, or daisy chained, whilst each valve assembly 10 services its own fluid line (not shown). For example, the valve assemblies 10 may be distributed throughout a gym, one being provided for each individual shower. The system 50.1 includes a base station 9 which centralises control, power supply and communication with the valve assemblies 10 and with a remote device, i.e., mobile phone 18 of a user. The base station 9 communicates with the user via a wireless or cloud-based communication network. The base station 9 may be configured to publish valve status, battery level, water temperature and total volume of fluid used to the cloud.

An alternative embodiment of a system 50.2 is shown in Figure 4B which includes a remote power supply 52 which is distinct and separate from the base station 9. Instead of a wireless communication module, the system 50.2 includes a keypad and display unit 54 for relaying status and control information to/from a user. The remote power supply 52 allows for better routing of power/comm unication wires. Multiple strings of valve assemblies may also be connected to the base station 9 in Figure 4A, should the need arise to do so. The Applicant believes that the valve assembly 10 and method 30 in accordance with the invention will encourage conservative water usage. If the valve assembly times out whilst in the PAUSED state, the valve assembly 10 is reset to its OPEN state. The reset threshold period T4 should be sufficiently long to prevent misuse of the PAUSED state to restart the valve assembly which would defeat the purpose of the assembly.

The warning action 38 may include a temporary restriction in water flow through the valve assembly using the valve 12.2. The user will then experience a change in temperature in a mixed hot-and-cold water scenario, or a distinct change in flow in a hot-water-only scenario. It will be understood that the valve assembly 10 may also be connected to a cold-water supply line to conserve use thereof. An advantage of the invention over the prior art is that the warning action, i.e., change in flow, is perceivable visually, audibly and through tactile perception (touch). The prior art configurations are only perceptible visually or audibly.

The valve assembly 10 may also include a hold-open state in which the valve is held open indefinitely and a hold-closed state in which the valve is closed.

If the hot and cold water is mixed as is the case with a shower, a solution is to install the Smart Valve on the mixed water line. If this is not an option, for instance at a wash basin, the problem can be solved by configuring a separate valve on the cold-water line in a slave configuration. In this configuration the slave valve always tracks the master valve, and the master valve is the one implementing the warning.

The operating principle of the flow sensor 14 is by means of an impeller driven by the flow of the fluid. There are embedded magnets in the impeller and its movement is detected by a sensor on the flow sensor body. The frequency of the impeller pulses corresponds with the flow rate of the fluid. The energy expended by the flow of the fluid to turn the impeller can be harvested and stored in the backup battery. Depending on the flow rate and design of the flow sensor, this can result in a self-sustained smart valve assembly that either does not require external power or makes minimal use of external power.

Ease of installation is another advantage of the invention. The compression couplings 11 on an inlet and outlet side of the valve assembly 10 permit easy connection to existing plumbing installations. There is also no need to install an audio or visual warning system where the user can hear or see it. In addition, the warning action of the valve assembly 10 will suit those with visual or auditory impairment. Timing and other user parameters that determine operation of the assembly are customizable as required by the use case using the mobile application. The state of the valve assembly will be easily verifiable using the mobile application. In other words, a person wanting to take a shower will want to check if hot water is in use and verify that he or she is able to start a shower with a fresh cycle, and not in the middle of another person’s usage cycle.

Ultimately the purpose of the valve assembly 10 is to conserve resources (e.g. water, electricity or gas) and save money. The operation of the assembly is not dependant upon the way water is heated and can therefore be used with any type of water heater. Any place where water or other fluids are being consumed can benefit through use of the assembly to curb misuse or overuse of limited resources and to encourage forming of new or better habits toward conservation of consumable resources. Also, Wi-Fi infrastructure is not required for operation of the assembly. There are also advantages associated with the use of the motorised valve 12. It uses very little power and has a slow open and close transition that does not cause pressure impulses on the plumbing system that can cause fatigue and damage to a home’s plumbing over time.