WO2004048706A2

WO2004048706A2 - Water flow control system

Info

Publication number: WO2004048706A2
Application number: PCT/GB2003/005121
Authority: WO
Inventors: Aidan M. Salter; Kenneth F. Oakley; Scott J. Hodges
Original assignee: Aliaxis R & D
Priority date: 2002-11-25
Filing date: 2003-11-25
Publication date: 2004-06-10
Also published as: WO2004048706A3; GB0512819D0; AU2003292373A1; GB0227433D0; GB2411244A; GB2395573A

Abstract

A water flow control system for monitoring and controlling the flow of water into a property to prevent leaks and abnormal water usage, e.g. taps which have accidentally been left running. The apparatus (100) comprises a water meter (130) for measuring the volume of uninterrupted flow into a property and a timer for measuring the period of uninterrupted flow. If either the time or the volume of uninterrupted flow exceeds predetermined time and volume values a stop valve (123) is activated to cut off the flow through the apparatus. If the flow is interrupted before either of these values is reached the timer and water meter are re-set. The predetermined cut off time is set by the user and the predetermined cut off volume is then automatically set based on the user inputted time.

Description

Water Flow Control System

This invention relates to a means of monitoring and controlling the flow of water into a property and in particular to one which cuts off the water supply upon detection of an abnormal water usage.

Abnormal water usage includes a tap which has been left running accidentally and both large and small leaks. Large leaks are those such as burst or fractured pipes, wherein a large volume of water is expelled in a short space of time. Not only do such leaks result in a large amount of wasted water, but if not stopped quickly they can cause extensive damage to the property.

Small leaks are those that are caused by faulty water appliances, such as taps or toilets, wherein a continuous trickle of water is released. While such leaks are less likely to cause damage, if left over time they can cause substantial water wastage and cost the property owner in increased water bills. This also applies to the situation when a tap is left running. Small leaks may also result from small holes in pipes, which may cause damage. In order to alleviate the environmental and financial damage caused by abnormal water usage, several devices exist which switch off the supply of water to the property when certain conditions are observed.

One such device is a battery operated unit which replicates a stop valve but allows it to be turned on and off by a switch. The switch can be activated manually by the property owner when water will not be needed over an extended time, e.g. when going on holiday, or set over a 24 hour period, e.g. an office water supply can be shut off nightly. Further, the switch is activated automatically when the temperature falls below 3°C. This device is very simple and is not of use in situations where a leak or accidental tap use occurs during a period when the building is in use.

More sophisticated devices are also available. These include a timer to monitor periods of uninterrupted flow into a property through the mains riser. A cut off time can be set so that if uninterrupted flow continues after this period has elapsed the supply is halted. While these devices may be sufficient for dealing with small leaks, a burst pipe would be able to cause a lot of damage prior to the chosen cut off time. Therefore, other devices use the flow rate or pressure drop as indications of when a major leak has occurred. Once again, a certain cut off value is set which triggers the shut down of the water supply.

The above appliances are suited to detecting either large or small leaks and therefore do not give overall protection. United Kingdom Patent Application No. GB 2371375 A discloses a water wastage control system in which the flow rate and time of uninterrupted flow are monitored. The flow rate can either be measured directly or can be calculated through repetitive volume readings which are then divided by the elapsed time. The system has a control unit preprogrammed with a "predetermined characteristic" which causes the stop cock to close after a certain time period has elapsed. However, the cut off time varies according to the average flow rate of the uninterrupted flow. Therefore a high flow rate, such as that resulting from a burst pipe, will be shut off after only several minutes whereas a low flow rate may be left to run for a much longer period.

However, different properties will require different cut off periods depending on the number of inhabitants, water usage etc. For example, an office may only require water for washrooms and kitchens . Water consumption in these areas tends to be in short bursts. As no extended water use takes place, e.g. baths and showers, the cut off time period may be smaller than is necessary for domestic residences. Further, a single person household will require a lower flow rate cut off than a larger household, where several water usages may take place at once.

To overcome this problem, the known control system is programmed with several alternative settings. The user selects the one most suitable by turning a dial on a control panel .

Once the control system has been preprogrammed within the factory with the alternative settings, no further adjustments can be made by the user. Therefore the system is very inflexible to individual needs. As such, a single person who wishes to take a long shower may not be able to so without the water supply being cut off part way through. To overcome this, they will have to increase the setting to that of a 2 or 3 person household, which hampers the effectiveness of the system as smaller leaks will then be allowed to run for longer. Further, households with power showers will require a greater allowance of flow rate than those without.

The inventor of the present invention has realised that a system can be provided which operates at a level between these two systems, which gives greater control than single variable monitors but more flexibility than the system of GB 2371375 A.

Viewed from one aspect, the present invention provides a water flow control apparatus comprising,- a meter for measuring the continuous volume of uninterrupted flow through the apparatus; a timer for measuring the time period of uninterrupted flow; a stop valve arranged to close and stop the flow through the apparatus; control means for closing the stop valve if either a) a predetermined continuous volume is measured, or b) a predetermined time period of uninterrupted flow elapses, whichever occurs sooner, wherein the predetermined time is set by the user and the predetermined volume is automatically selected by the control means based on the user's predetermined time; and means for resetting the time and volume measurements when the flow is interrupted prior to either predetermined value being reached.

Viewed from another aspect the present invention provides a method of controlling water flow, comprising the steps of: measuring the continuous volume of uninterrupted flow through a system; measuring the time period of uninterrupted flow; closing a stop valve to stop the flow through the system if either a) a predetermined continuous volume is measured, or b) a predetermined time period of uninterrupted flow elapses, whichever occurs sooner, wherein the predetermined time is set by the user and the predetermined volume is automatically selected based on the user's selection of the predetermined time; and resetting the time and volume measurements when the flow is interrupted prior to either predetermined value being reached.

Therefore, the apparatus of the present invention monitors two parameters independently of each other. In this way, large leaks can be stopped more quickly than if only the time was being monitored and small leaks more quickly than if purely the volume was considered. The apparatus can be easily adjusted for use in a variety of different households as the user sets a predetermined time taking into account, e.g. how long they like to spend in the shower. The apparatus then automatically sets a predetermined volume based on a predetermined relationship between time and volume. In this way the user does not need to calculate a suitable cut off volume, something which a person with no knowledge of water consumption rates may find difficult. The predetermined relationship can be factory set and be equivalent to the highest flow rate typically used in a domestic household, such as the bath filling flow rate. In this way, the user inputs a time and the control means uses the given flow rate to calculate the maximum allowable volume which can be used within this time. Different relationships can be used in apparatus designed for other fields, such as agriculture, office blocks or industry, which will all have different water consumption habits. In addition it is preferable for the relationship to consist of several different flow rates. For example, while the bath flow rate may be the highest flow rate used domestically this will only be used for a short period of time, i.e. that required to fill the bath. Therefore after this time has elapsed the relationship could be switched to become equivalent to a lower flow rate, such as the shower flow rate. In this way the relationship can be used to determine a cut off volume which allows the water supply to be used normally but which will quickly detect abnormal water usage . Preferably the user can adjust the relationship to take account of the household's individual water system. This can be done by adjusting the time when the relationship switches from a high to a lower flow rate (e.g. the bath and shower flow rate) . Again this feature allows the user to better adapt the system for his own use without requiring him to be familiar with water consumption rates. In some circumstances, it is also preferable that the user can alter the flow rates used in the relationship. This would be beneficial for example in industry or agriculture when the user would be more aware of their usual water usage than a standard householder. Once the predetermined relationship has been specifically adapted to the user's requirements it is used to calculate a predetermined cut off volume based on the predetermined time chosen by the user.

Very small leaks, such as a slowly dripping tap, are common and do not emit much water. A system which disables the water supply when such a leak occurs may be considered more of a hindrance than a help. Therefore, it is preferable that the control means interprets flow rates falling below a threshold value to constitute an interruption in the flow.

In this way the stop valve is not activated to prevent fairly minor leaks and disruption to the water supply is only caused to prevent potentially significant water wastage. The threshold value can be set at whatever level considered suitable. A preferred threshold value is approximately lL/min. The threshold value could be set by the user but is preferably factory set.

The effectiveness of the apparatus is increased by using a sensitive meter, so that small volumes passing through the apparatus can be detected. Preferably, the meter is capable of measuring flow rates less than the threshold value. In this way, the effectiveness of the apparatus is better than if the meter can only detect relatively high flow rates.

The apparatus may operate continuously while activated in order to ensure any abnormal water usage is always detected and halted. However, there may be situations where the user wishes to use water for an extended period, or a greater volume of water than usual. For example, he may wish to water his garden.

In such circumstances the water control apparatus would need to be deactivated to allow the necessary activity to take place uninterrupted. However, there is then the possibility that the user will forget to switch the apparatus back on, leaving the property in danger of water wastage and damage.

Therefore, the apparatus preferably further comprises an override for overriding the control means so that the stop valve is kept open for a predetermined time period. Preferably this time period is factory set. In this way, the control apparatus will automatically be reactivated, giving greater protection to the property.

Once the control means has been activated and the water supply discontinued, the stop valve needs to be re-opened. This can be done either once the leak has been fixed, or in order to locate it. The control means may therefore also operate to open the stop valve upon a command from the user.

However it is also preferable that the apparatus further comprises means for manually closing or opening the stop valve. In this way the user can close the valve if no water is required for a considerable period, for example, during a holiday. Preferably this means can also be used to open the valve. This may be useful to enable reopening of the stop valve during a power failure, e.g. battery failure.

While the various components of the apparatus can be positioned at different locations around the property, for example the control means could be located at an easily accessible point for the user, it is preferable that the meter and the stop valve are located in a common housing. This makes the apparatus easier to install into a pre-existing water system.

More preferably, all the components are located in a common housing. This again eases the installation cost and decreases the possibility of malfunction due to the components becoming disconnected from the control means .

The meter can be any device which allows the volume of flow passing through the apparatus to be accurately measured, for example, any meter used by water suppliers. However, preferably the meter comprises: a cylindrical cavity in which a piston is eccentrically housed, the piston being arranged to undergo repeated cycles of generally circumferential movement wherein each cycle allows a fixed volume of water through the apparatus, the piston having a radially outer wall which engages and sweeps round a radially outer wall of the cylindrical cavity during a cycle of movement; a magnet provided on the radially outer wall of the piston to move therewith; and a detector located on or adjacent to the radially outer wall of the cylindrical cavity, the detector being arranged to detect the magnet each time the magnet comes into proximity therewith and thereby detect each cycle. This device is inventive in its own right and therefore, viewed from another aspect the invention provides a water flow control apparatus comprising: a meter for measuring flow through the apparatus; a stop valve arranged to close and thereby stop the flow through the apparatus; and control means for closing the stop valve when an abnormal water usage is detected; wherein the meter comprises: a cylindrical cavity in which a piston is eccentrically housed, the piston being arranged to undergo repeated cycles of generally circumferential movement wherein each cycle allows a fixed volume of water through the apparatus, the piston having a radially outer wall which engages and sweeps round a radially outer wall of the cylindrical cavity during a cycle of movement ; a magnet provided on the radially outer wall of the piston to move therewith; and a detector located on or adjacent to the radially outer wall of the cylindrical cavity, the detector being arranged to detect the magnet each time the magnet comes into proximity therewith and thereby detect each cycle. By locating the detector on or adjacent the radially outer wall of the cylindrical cavity, space is saved in the axial direction. Moreover, this space can be advantageously be used to accommodate other components, in particular the stop valve.

Preferably, therefore the stop valve is disposed axially adjacent to the meter and wherein the control means comprises a printed circuit board disposed laterally of the meter. Preferably the detector is a reed switch. This can then deliver an electrical pulse upon each rotation of the rotor.

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which;

FIG 1 shows a first embodiment of the water flow control apparatus of the present invention;

FIG 2 shows the inlet side of the water flow control apparatus with the inlet panel removed;

FIG 3 shows the outlet side of the water flow control apparatus with the rear plate and outlet panel removed;

FIG 4 shows the outlet side of the water flow control apparatus with the rear plate removed and the outlet panel shown separated,-

FIGS 5A-C show a schematic diagram of the operation of the bypass circuit;

FIG 6 shows a second embodiment of the water flow control apparatus of the present invention;

FIG 7 shows the apparatus of FIG 6 with the casing emoved;

FIG 8 shows the gear system used in the second embodiment of FIG 6 ; FIG 9 shows the stop valve system used in the second embodiment with the inlet section of pipe removed;

FIG 10 shows the stop valve system used in the second embodiment with the outlet section of pipe removed; and

FIG 11 shows a relationship between time and volume for use in both embodiments.

FIG 1 shows the exterior a first embodiment of the water flow control apparatus 10. In order to protect the entire property the control apparatus 10 can be positioned on the main riser after the stop cock. However, it is conceivable that the control apparatus 10 could be positioned at other strategic places within the plumbing system such as upstream of bathrooms or kitchens. In a hotel a control apparatus 10 could be supplied for each room. The control apparatus 10 has a main casing 11 with front and rear plates 13a, 13b. Fastened to the front and rear plates 13a, 13b respectively are inlet and outlet panels 12, 14. Water enters the control apparatus 10 through an inlet pipe 12a and exits through an outlet pipe 14a. The casing 11 also contains a control panel with a display (not shown) for interface with the user.

An indicator window 15 is visible on the casing 11 and alerts the user to the present status of the system as will be explained later.

FIG 2 shows a side view of the control apparatus 10, in which the inlet panel 12 has been removed to reveal certain components of a water meter. The water meter comprises a cylindrical cavity 17 defined by a radially outer wall 52 and which contains a piston 18 of smaller diameter. The construction and relationship of the cavity and piston are of a known type, see WO 93/22631.

The piston 18 comprises a radially outer wall 54 defining a hollow cylinder 18a with a central plate 18b positioned therein. The plate 18b is perforated by a number of holes to allow the passage of water through the piston 18. As well as these holes the plate 18b also contains an orifice 18c. This is shaped to permit the piston 18 to reciprocate along a divider wall 19 projecting radially inwardly from the radial outer wall 52 of the cavity 17. A magnet 180 is attached to the exterior of the cylinder 18a.

In use, water enters the cavity 17 via a crescent shaped inlet fed by the inlet pipe 12a and exits through a correspondingly crescent shaped outlet 16 leading to outlet pipe 14a. The inlet and outlet are situated on opposite sides of the divider wall 19 and at opposite axial ends of the cavity 17. The flow of water through the cavity 17 causes the piston to undergo a generally circumferential movement around the cavity. During this movement the radially outer wall of the piston engages and sweeps round the radially outer wall of the cavity. A completed cycle of such movement allows a fixed volume of water (i.e. a metered volume) to pass from the cavity inlet to the cavity outlet. Thus a complete cycle of movement is equivalent to a specific volume passing through the cavity 17. In this instance one rotation is equivalent to approximately 33cl but other size meters could of course have other volumes .

The movement of the magnet 180 during this movement is used to detect each rotation as will be described later.

FIG 3 shows the outlet side of the control system 10 in which the rear plate 13b and outlet panel 14 have been removed. Water exiting the cavity 17 through outlet 16 passes laterally along conduit 26 and then out axially via the outlet pipe (not shown) . The conduit contains a cylindrical chamber 28 which extends parallel with the axis of the cylindrical cavity 17 and coaxially with outlet pipe 14a. This cylindrical chamber 28 houses piston valve 25.

The upper section of casing 11 contains a printed circuit board (PCB) 21, powered by battery pack 20. This PCB 21 contains all the programming necessary for operating the control apparatus 10. A magnetic sensor such as a reed switch 50 is positioned near the base of the PCB 21 in close proximity to radially outer wall of the cavity 17. An electric solenoid 22 is positioned between the PCB 21 and a shut off arm 23. The shut off arm has an indicating portion 23a which is located close to the indicator window 15. The indicating portion consists of two coloured areas, one green and one red. The shut off arm has a pivotally mounted pivot rod 23c fixed thereto so that the shut off arm is pivotable with the pivot rod 23c about the axis thereof. The pivot rod extends through a hole 32 in the outlet panel 14 (see FIG 4) and is formed with a slot enabling it to be rotated by a screwdriver. This enables manually effected closure of the stop valve.

The layout of the bypass circuit will now be described with reference to FIGS 4 and 5A-C. In FIG 4 the piston valve 25 has been removed. The cylindrical chamber 28 contains stops 28a against which piston 25 is biased by a spring 35 (shown in FIGS 5A-C) . This creates a gap in the chamber 28 behind the piston 25. An opening 28b is provided in this gap which leads to a channel 29. The outlet panel 14 also contains a channel 30.

This extends from the outlet pipe 14a on the exterior of panel 14 inwards towards channel 29. The channels 29, 30 are separatable form each other by shut off arm 23. The shut off arm 23 is formed with a hole 31, which can be used to bring the two channels 29, 30 into communication. An annular seal 40 is provided at the junction between channel 30 and the shut off arm 23 and another annular seal (not shown) is provided at the junction between the shut off arm 23 and channel 29. These seals provide respective water tight links.

The use of the apparatus will now be described. During each rotation of the piston 18, the magnet 180 is brought close enough to the PCB 21 to operate the reed switch 50. This creates an electric pulse for each rotation and hence the total continuous volume passing through the control apparatus 10 can be obtained.

The PCB 21 also contains a timer (not shown) and a logic circuit for comparing the signals obtained from the reed switch 50 and timer against the predetermined limits. The user sets the predetermined time limit via a control on the control panel. The PCB 21 is preprogrammed with information regarding a relationship between time and volume, see FIG 11. This relationship is based on the highest acceptable flow rate at a given time. The highest flow rate obtained in a standard household is the bath flow rate. Therefore, the relationship between cut off volume and time is initially set to follow this flow rate, e.g. lOOOL/hour. At this flow rate a standard bath will be full within approximately 12 minutes, after which time a continued flow at this rate will indicate a leak or that the bath is overflowing. The next highest flow rate in an average household is that of the shower, which is approximately 300L/hour. Showers are generally run for longer than baths and therefore after 12 minutes the programmed relationship switches to this lower flow rate. This is called the switch point 60.

Therefore, if the user sets the time limit to be, e.g. 15 minutes, the PCB 21 will use this relationship to automatically set the volume limit at 255L. Consequently, if a small tap is left running the system will close the water supply when it records over 15 minutes of uninterrupted flow. However, if a bath tap is left running the system will cut off the water supply sooner as the volume will exceed the maximum volume allowed prior to the expiry of 15 minutes. If a higher time is set then the PCB 21 will set a corresponding higher volume .

The switch point 60 can be adjusted by the user when the system is first installed to take account of differences in water pressure or bath sizes. The user can set the switch point 60 based on the time it takes his bath to fill up to a normal level . After this the user simply enters the longest time of uninterrupted flow thought likely to occur during normal use of the water supply as the predetermined cut off time. The specifically adapted relationship will then provide the system with the corresponding cut off volume. Once the time is set by the user and the volume is automatically set, these two parameters are then monitored separately and independently of each other. In the above example the flow would be cut off after 15 minutes even if the volume had only reached, say, 60 litres .

As the meter is so sensitive to low flow rates a threshold is set under which the PCB records "no flow" . This limit is somewhere in the region of lL/min, which is equivalent to a slowly dripping tap. Once the reed switch indicates that the flow rate has exceeded this value, the timer begins to count the duration of the flow while the total volume of continuous flow is also accumulated by the PCB 21. If the flow rate falls below lL/min before either cut off value has been reached the time and volume measurements are reset to zero.

However, if either the time or the volume cut off values are exceeded, the logic circuit acts to power the solenoid 22. The solenoid 22 acts upon the shut off arm 23.

The shut off arm 23 has two functions. Firstly it acts to open and close the bypass circuit. When the bypass circuit is closed the piston valve 25 is forced along the chamber 28 and blocks the outlet pipe 14a, cutting off the water supply to the property.

Secondly, the shut off arm 23 acts as an indicator as to the operational status of the control apparatus 10. The indicting portion 23a of the shut off arm 23 lies close to the indicator window 15 on the casing 11. During normal operation the green area of the indicating section 23a is aligned with the window 15. When the shut off arm 23 is activated in order to close the outlet pipe 14a, the arm 23 pivots about the axis of rod 23c and the red area is brought into line with the window 15, so that the user can see that a shut down has been triggered. When the solenoid 22 is off the shut off arm 23 is positioned such that hole 31 is in line with channels

29, 30. Therefore, as shown in FIG 5A, water flows past the piston 25, through the channels 29, 30 and out of the outlet pipe 14a. The piston 25 is slightly undersized relative to the chamber 28, allowing seep past the piston 25 and reach the bypass system.

If the PCB 21 registers either an excess in continuous volume or the elapse of the predetermined time period, the solenoid 22 is activated. The head section 23b of shut off arm 23 is attracted towards the solenoid 22 and the hole 31 is off set from channels 29,

30. This prevents water exiting through channels 29, 30 and instead pressure begins to build up in the gap behind piston valve 25, as shown in FIG 5B. The pressure overcomes the force of the spring 35 and the piston valve 25 is forced forward to block the outlet pipe 14a, as shown in FIG 5C.

Once the solenoid is deactivated the hole 31 realigns with channels 29, 30 and water once again flows through the bypass system. This reduces the net closure pressure on the piston valve 25 and the spring pushes the piston 25 back in the opening direction of the chamber 28, allowing water to exit the outlet tube 14a. Alternative known shut off valves could be used. Also, the solenoid could be replaced by an electric motor .

Shut down or opening of the water supply can also by manually achieved by rotating pivot rod 23c by a screwdriver. This turns the shut off arm 23 and so allows the bypass to be opened or closed.

FIGs 6 to 10 show a second preferred embodiment of the water flow control apparatus of the present invention. FIG 6 shows the exterior of the water flow control apparatus 100. This consists of upper and lower casing Ilia, 111b which are integrally joined together. Upper casing Ilia contains a door 115 which allows access to batteries 116 and 118 (see FIG 7) . These batteries 116, 118 power the apparatus 100. Using batteries ensures the system will still operate in the event of a power cut. The door 115 only allows access to the batteries 116, 118 and thus it is not possible to tamper with the workings of the apparatus 100. Door 115 can be locked by means of padlock 117. Upper casing Ilia also comprises an opening shaped to fit control panel 113 and a display panel (not shown) for interface with the user.

Water enters the apparatus 100 through inlet pipe 120 and exits via outlet pipe 127, both of which extend through lower casing 111b, although it is also possible for the inlet and outlet pipes 120, 127 to extend through the apparatus 100 in a straight line to reduce the noise of the system. Water flows through inlet pipe 120 into a water meter 130 of the type discussed in relation to the first embodiment. The reed switch (not shown) used to detect the rotation of the piston is located in close proximity to the meter 130, on or adjacent to its radially outer wall, and is connected to PCB 119 via flying leads. Therefore, the second embodiment measures the volume of uninterrupted flow in the same manner as the first embodiment. However, the stop valve used to cut off the flow of water into a household or area differs as described below.

Water leaving the meter 130 via outlet 131 flows through conduits 121, 122 and exits the apparatus 100 through outlet pipe 127. Where the side pipes 121, 122 are joined together they widen in diameter to form housing for a ball stop valve 123 (see FIGs 9 and 10) . The ball stop valve 123 consists of a sphere having stem members 123a, 123b at its poles and a hollow passage 124 extending through the sphere perpendicular to the plane of the poles 123a, 123b. When this passage 124 is in line with the water channel created by conduits 121, 122 water can flow freely through the device. However, when the valve 123 is rotated 90° such that the passage 124 is moved out of alignment with the channel, the flow of water is blocked and the supply cut off .

The valve 123 is rotated by a motor 151 and gear train 152 located in gear box 150. The motor 151 is electrically connected to the PCB 119 by flying leads and is activated when a leak is detected by the system. The motor 151 rotates gear train 152 to reduce the speed of rotation and increase the torque produced. The final gear in the series is connected to stem member 123b of valve 123 and rotates the valve 123 through 90°. The gear train enables the valve 123 to be closed even when a large volume of water is flowing through the apparatus 100 resisting the valve's rotation. The valve can be re-opened in two ways. Firstly, pressing a reset button on the control panel 113 will cause the motor to rotate the valve a further 90° to re align the passage 124 and the water channel. It is also possible to manually reset the valve 123 in case of electrical failure. This is achieved through turning a knob (not shown) on the casing 111 which is connected to a gear in the gear train 152 to rotate the valve 123 in to the desired position.

Stem members 123a, 123b also serve to anchor the valve 123 within the conduits 121, 122. Conduit 122 contains grooves into which members 123a, 123b fit. Conduit 121 has corresponding detents 126 which slide along the grooves 125 to fix conduits 121, 122 together and hold the valve 123 firmly in place. In both embodiments, the control panel can also by used to override the control apparatus 10, 100 for a limited period defined by the user. This allows the user to carry out activities of extended duration, such as watering the lawn, that would be classified as abnormal occurrences by the apparatus 10, 100 and lead to the shut down of the water supply. The leak detection method of the second embodiment is identical to the first embodiment and is therefore not repeated.

Therefore, there is disclosed herein, water wastage flow control apparatus, i.e. apparatus that helps to protect against water wastage, e.g. leaks, bursts and accidental tap use. The apparatus provides flexibility for the user without undue complexity. The system is able to respond to a predetermined cut off time irrespective of the uninterrupted volume which has flowed or the rate at which that volume has flowed.

Claims

1. Water flow control apparatus comprising; a meter for measuring the continuous volume of uninterrupted flow through the apparatus; a timer for measuring the time period of uninterrupted flow; a stop valve arranged to close and stop the flow through the apparatus; control means for closing the stop valve if either a) a predetermined continuous volume is measured, or b) a predetermined time period of uninterrupted flow elapses, whichever occurs sooner, wherein the predetermined time is set by the user and the predetermined volume is automatically selected by the control means based on the user's selection of the predetermined time; and means for resetting the time and volume measurements when the flow is interrupted prior to either predetermined value being reached.

2. Apparatus as claimed in claim 1, wherein the predetermined volume is selected by a predetermined relationship which can be adjusted by the user.

3. Apparatus as claimed in claim 1 or 2 , wherein in use the meter measures flow rates and the control means interprets flow rates falling below a threshold value to constitute an interruption in the flow.

4. Apparatus as claimed in claim 3, wherein the threshold value is 1 L/min.

5. Apparatus as claimed in claim 3 or 4, wherein the meter is capable of measuring flow rates less than the threshold value.

6. Apparatus as claimed in any preceding claim, further comprising an override for overriding the control means so that the stop valve is kept open for a predetermined time period.

7. Apparatus as claimed in any preceding claim, further comprising means for manually closing or opening the stop valve.

8. Apparatus as claimed in any preceding claim, wherein the meter and the stop valve are located in a common housing.

9. Apparatus as claimed in any preceding claim, wherein the meter comprises : a cylindrical cavity in which a piston is eccentrically housed, the piston being arranged to undergo repeated cycles of generally circumferential movement wherein each cycle allows a fixed volume of water through the apparatus, the piston having a radially outer wall which engages and sweeps round a radially outer wall of the cylindrical cavity during a cycle of movement; a magnet provided on the radially outer wall of the piston to move therewith; and a detector located on or adjacent to the radially outer wall of the cylindrical cavity, the detector being arranged to detect the magnet each time the magnet comes into proximity therewith and thereby detect each cycle.

10. Water flow control apparatus comprising; a meter for measuring flow through the apparatus ; a stop valve arranged to close and thereby stop the flow through the apparatus; and control means for closing the stop valve when an abnormal water usage is detected; wherein the meter comprises : a cylindrical cavity in which a piston is eccentrically housed, the piston being arranged to undergo repeated cycles of generally circumferential movement wherein each cycle allows a fixed volume of water through the apparatus, the piston having a radially outer wall which engages and sweeps round a radially outer wall of the cylindrical cavity during a cycle of movement; a magnet provided on the radially outer wall of the piston to move therewith; and a detector located on or adjacent to the radially outer wall of the cylindrical cavity, the detector being arranged to detect the magnet each time the magnet comes into proximity therewith and thereby detect each cycle .

11. Apparatus as claimed in claim 10, wherein the stop valve is disposed axially adjacent to the meter and wherein the control means comprises a printed circuit board disposed laterally of the meter.

12. Water flow control apparatus substantially as hereinbefore described with reference to the accompanying drawings .