GB2395573A

GB2395573A - Water flow control system

Info

Publication number: GB2395573A
Application number: GB0227433A
Authority: GB
Inventors: Aidan M Salter; Kenneth F Oakley; Scott J Hodges
Original assignee: MULTIKWIK Ltd
Current assignee: MULTIKWIK Ltd
Priority date: 2002-11-25
Filing date: 2002-11-25
Publication date: 2004-05-26
Also published as: WO2004048706A2; WO2004048706A3; GB0227433D0; AU2003292373A1; GB2411244A; GB0512819D0

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 10 comprises a water meter <WC 1>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 <WC 1>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.

Description

Water Flow Control System 5 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 10 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 15 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 20 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.

25 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 30 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 35 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.

5 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.

10 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.

15 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. 20 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 25 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 30 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 35 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.

5 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 10 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 15 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 20 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 25 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 30 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 35 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; and means for resetting the time and volume measurements when the flow is interrupted prior to either predetermined value being reached. 5 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 10 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; and resetting the time and volume measurements when the flow is interrupted prior 15 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 20 more quickly than if purely the volume was considered.

Preferably the predetermined time is set by the user. For example, a householder can set the predetermined time taking into account how long they like to spend in the shower. The apparatus may then 25 automatically set a predetermined volume.

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, 30 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 35 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 0.75L/min. The threshold value could be set by the user but is preferably factory set.

5 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 10 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 15 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 20 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 25 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 30 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 35 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, 5 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 10 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 15 install into a preexisting 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 20 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 25 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 30 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 35 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 5 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 10 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 15 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 20 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 25 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.

30 Preferably the detector is a reed switch. This can then deliver an electrical pulse upon each rotation of the rotor.

An embodiment of the present invention will now be described, by way of example only, with reference to the 35 accompanying drawings, in which; FIG 1 shows 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 5 removed; FIG 4 shows the outlet side of the water flow control apparatus with the rear plate removed and the outlet panel shown separated; and FIGS 5A-C show a schematic diagram of the operation 10 of the bypass circuit.

FIG 1 shows the exterior a preferred 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.

15 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.

20 The control apparatus 10 has a main casing 11 with front and rear plates 13a, lab. 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 25 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 30 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 35 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 5 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 10 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 15 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 20 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 25 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.

30 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 35 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.

5 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 lO 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 15 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 20 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 25 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 30 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.

35 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.

S 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 10 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 15 a control on the control panel. The PCB 21 is pre-

programmed with information regarding a relationship between time and volume. 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 20 limit at SOL. If a higher time is set then the PCB 21 will set a corresponding higher 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. However, 25 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 30 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 0.75L/min, which is equivalent to a slowly dripping tap. Once the 35 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 0.75L/min before either cut off value has been reached the time and volume measurements are reset to zero. 5 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 10 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 15 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 20 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.

25 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 30 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 35 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 5 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 10 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. 15 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.

The control panel can also by used to override the 20 control apparatus 10 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 and lead to the shut down of the water supply.

25 Therefore, there is disclosed herein, water wastage flow control apparatus, i.e. apparatus that helps to protect properties against water wastage, e.g. leaks, bursts and accidental tap use. The apparatus provides flexibility for the user without undue complexity. The 30 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 S 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; lO control means for closing the stop valve if either a) a predetermined continuous volume is measured, or b) a predetermined time period of 15 uninterrupted flow elapses, whichever occurs sooner; 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 time is set by the user.

3. Apparatus as claimed in claim 1 or 2, wherein in 25 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 30 threshold value is 0. 75 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, 5 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 10 common housing.

9. Apparatus as claimed in any preceding claim, wherein the meter comprises: a cylindrical cavity in which a piston 15 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 20 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 25 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.

30

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 35 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 5 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 10 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 15 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 20 board disposed laterally of the meter.

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