Fluid leakage and fluid flow detection for preventing and limiting damage

Abstract: A leakage detection device is provided for a fluid supply system. The detection device includes control means (12) which can be selectively operated to close a valve (10) and hence prevent further supply. The device includes at least one sensor (8) which senses the flow of fluid through the supply system. Thus the device allows detection of fluid leakage and flow rates and can prevent or limit damage caused by fluid leakage.

Description: The invention to which this application relates is a device for detecting fluid leakage in a fluid supply system such as, for example, a water supply in domestic premises. The device is provided to prevent the damage which leakage can incur by shutting off the supply of fluid when leakage is detected. It is well known that leakage from fluid pipes within a domestic premises can be extremely damaging in domestic premises and industrial premises and can cause damage to both apparatus, appliances in the premises and also to the fabric of the premises itself. The damage may also be caused to other premises if the fluid which is leaked causes ceilings to collapse and the like. The problem of leakage is particularly prevalent when the premises are empty and therefore leakages can go undetected for a period of time if, for example, the occupiers of the premises are on holiday, at work, or if indeed the premises are unoccupied. There are known to be several different forms of devices which are provided to detect leakage but these known devices are relatively complex and require detection at various different points on the fluid system before the same is activated. The complexity and hence expense of these known devices such as for example that shown in GB2319634 which requires a plurality of flow sensors to be positioned throughout a premises means that there has been no large scale adoption of the same and as a result leakages still tend to go undetected. US-4518955 discloses a supply which moves a valve to a closed condition when a flow of fluid is detected over a period of time which exceeds a normal predetermined fluid drainage time from the system. The system therefore needs to be in a constantly active state and the closing of the fluid drains to occur to allow an accurate fluid flow detection to be achieved. US-5007803 relates to a control system for an air operated vacuum pump for a liquid. The control system in this patent relates to the control of operation of the pump cycles. The system is only of any use when active. If inactive the pump does not operate and there is no flow of liquid. US-5086806 detects the flow of liquid in a conduit to items such as beverage dispensing machines. The system is reliant on being active at all times in order to detect the start of a fluid flow, whereupon a flow rate counter is activated and the flow rate calculated. If a maximum flow count is exceeded a valve is shut, as is also the case if the flow of water exceeds a certain time. This device is not for use in relation to distribution systems in a premises. US-5441070 relates to a water management system. This system operates to open a valve when fluid flow is detected and shut the same when fluid flow is undetected. The system is active at all times. The applicant has appreciated this problem and the aim of the present application is to illustrate in more detail the provision of a leakage detection device which is relatively simple to operate, can be fitted to existing fluid systems and can be operated and adjusted to suit particular conditions relating to the premises at any instant. In a first aspect of the invention there is provided a water leakage detection device for a mains water supply into a premises connected to a water distribution system within the premises, the device allowing the selective closure of the water supply to the premises and said device includes a sensor which senses the flow of water through the distribution system and at least one valve which can be controlled to close or reduce the water supply to the supply system, and control means which allow the selective closure of the said valve in response to the sensor and characterised in that the control means allow the selection of the activation of the device and the said valve is held in a normal, open position, when inactive and, when active, the valve remains in the open position when no water flow is detected by the sensor, or when water flow is detected at an authorised time or below a preset fluid flow level, said valve being moved to a closed position when water flow is detected at an unauthorised time or above a preset fluid flow rate by the sensor. In one embodiment, the device includes a selectively operable control means to control at least one valve situated at the interface between a fluid supply and a distribution system, in the main supply system, or at various locations in the distribution system and the control means communicates with a number of flow sensors located throughout parts of the supply systems of concern so that for example, in a hotel there is provided a single selectively operable control unit on a mains water inlet with a sensor and control valve in each of the hotel rooms. The control means refers to each of the sensors at regular time intervals and if continued fluid flow is detected over a period of time, the valve for that particular location can be closed to prevent further flow. Ina simpler example for a domestic premises, the valve can be fitted at the introduction of the mains water supply into the premises so that if fluid flow is detected at an unexpected time, the valve can be moved to a closed position to prevent further water entering the premises. In a further embodiment, the leakage detection device is used on a mains supply system to control the mains supply to a number of different premises and to sense the supply of fluids to any of a number of premises. In one embodiment, more than one control means are provided to enable the device to be controlled from a number of locations in an area or premises. The control means can be provided at the mains inlet and/or remote from the mains inlet. In use in one embodiment, when the device is activated, and the control means does not sense any liquid flow, the valve is retained in an open position. In one embodiment, when the control means is activated and does detect a liquid flow the sensor causes the valve to move to a closed position and thereby prevents any further liquid from passing into the system into the premises. In an alternative embodiment the control means is set to sense a particular level of fluid flow so that, when activated, if the sensor detects a fluid flow at a rate which is below that to which it has been set, then the valve will be maintained in an open position. If the flow rate detected exceeds the pre-set level, the control means will activate the valve and closes the same to prevent any further flow of fluid into the premises or, alternatively may activate the valve to move to a position to restrict the flow to below the pre-set level. In addition, or alternatively, instead of measuring a particular level of flow, the device may be operated, when activated, to allow the flow of liquid for predetermined periods of time equivalent to, for example, the periods during which liquid is required to be supplied to a washing machine. It should therefore be appreciated that in this embodiment, the device is activated when fluid flow rates are required to supply an appliance such as a washing machine or dishwasher. The fluid supply periods can be predetermined and entered into the device so that if fluid is supplied during the predetermined time periods the device remains in the open position but if fluid flow is sensed outside these time periods or for a longer duration than the predetermined time the device valve is moved to a closed position to prevent any further fluid from being supplied. Typically, control means can be mounted within the premises and which allows the selection of the activation of the device and the particular control parameters within the device to be entered by the occupier of the premises or the owner of the premises. For example, if the occupier is going on holiday for a period of time, say a week, then the device can be set to be activated for that period of time so that if leakage is detected during that time, the device valve will be closed to shut the fluid supply off. Equally, the device can be set to be activated every night between set periods of time or, in particularly cold climates, the device may be manually activated every time the occupier leaves the premises so that the danger which is caused by frozen pipes can be avoided and if it occurs, the supply can be stopped. Furthermore, if no flow is recorded or detected by the detection device, then the device is effectively disabled. Once a flow rate is detected, the detection device is re-activated. In an alternative embodiment, the device can be used to secure unoccupied premises whereupon the device can be fitted by the owner of the premises and activated and it will remain activated until the premises are to be reoccupied whereupon the device can then be removed or controlled as described above. In a further feature the device can include in the control system a means whereby, when the batteries are low in power, the user is alerted. If the alerts are ignored then before the power is totally exhausted the device acts to turn off the fluid supply to the premises. This may also happen if there is a power cut and the device is powered from the mains. In one embodiment the leakage detection system can be connected to an alarm, such as a burglar alarm, to sound in the event of a leak. The leakage detection system can also be connected to, integrated with and controlled via a personal computer. In one embodiment the system uses telemetry whereupon no wiring is required between the selectively operable control unit, the one or more sensors or the one or more valves. In one embodiment the leakage detection device comprises at least one valve for the control of water entering into a water distribution system in a premises, at least one sensor for sensing the flow of water into and/or in the distribution system and a control means in communication with the sensor and valve, and wherein the valve is held in an open position when the control means is set to allow the flow of water through the system and into the premises, and the control means can be selectively controlled by a user to move the valve to a closed position for periods of time and/or upon receiving an indication of water flow when the control means is set to prevent the flow of water. Specific embodiments of the invention will now be described with reference to the accompanying drawings, wherein:- Figure 1 illustrates in schematic fashion the device according to the invention; Figure 2 illustrates a control panel for the control means of the invention. Figure 3a illustrates a schematic representation of one embodiment of the invention; Figure 3b illustrates a schematic representation of a further embodiment of the invention. Referring firstly to Figure 1, there is illustrated a device according to this invention fitted in accordance with a fluid supply system which in this case is a water supply system and it is envisaged that the invention is of particular use with water supply systems. In this first embodiment there is shown a water supply system for a premises, said water supply system comprising a mains supply 2 and domestic water distribution system 4 which allow the distribution of the water throughout the premises and to various appliances. The mains supply is typically provided with a stop cock 6 and in the vicinity of the stop cock the water flow sensor 8 of the device can be fitted in conjunction with a valve 10 as shown. The water sensor and valve are connected to the control means 12 mounted in the premises and which control means allows the control and activation of the water sensor and valve. Typically the valve is a solenoid valve and is held in a normal open position when the device is not activated and therefore allows unrestricted flow of water through the water system as normal. When activated, if no water flow is detected by the sensor through the pipes, then the valve is typically retained in an open position. In one embodiment if the device detects any water flow the valve is moved to a closed position to prevent the flow of any liquid from the mains into the premises supply system. In this embodiment the detection of liquid when the device is activated is taken to mean that there is a leakage somewhere in the premises supply system and that water is leaving the system through means other than the conventional tap or use by appliances. Thus, the closure of the valve prevents the further supply of water into the premises supply system and hence prevents further leakage into the premises. An alternative embodiment is for the device when activated to be controlled such that the sensor is set to sense liquid flow for a predetermined period of time and if the water flow stops within the period of time then the valve will remain in an open position. If, however the flow of liquid continues and exceeds the predetermined period of time then the valve will be moved to a closed position to prevent further water entering the premises. This particular arrangement is for use when, for example, the device is activated but an appliance which uses water such as a washing machine is in operation. For washing machines, water is supplied for predetermined periods of time and so the operation of the device to detect and allow water flow over predetermined periods of time allows the continued supply of water and allows the washing machine to be operational even when the device is activated. However, if water is flowing for a period greater than the predetermined period of time due to, for example, leakage, then the device can still be activated to prevent further supply of water. Figure 2 illustrates a control means panel 20 according to one embodiment of the invention wherein there are provided various means 22 by which the user may input control parameters for the device and which allows the device to be controlled to suit the particular requirements of the occupier of the premises in terms of when the device should be activated, whether it should be activated at the same time on repeated occasions and so on. The device can be activated when the premises are unoccupied and therefore any leakage would not be detected for a period of time and/or when the premises are occupied and the occupier may be asleep for example. The device according to the invention can be hardwired to the one or more valves and flow sensors, as illustrated in Figure 3a. Alternatively, the device can operate using telemetry wherein no wiring is required, as illustrated in Figure 3b. The control means 12 is thus provided with a radio transmitter and receiver 14 and the valve 10 and flow sensor 12 also communicate with a radio transmitter and a receiver 16. Thus, there is provided a device which can be used to advantage by the occupiers of premises, the owners of premises which may be unoccupied for a period of time and may be provided by water supply companies to allow detection of leakage and/or may be required by insurance companies as a means of preventing or limiting damage which is caused by fluid leakages.

Claims: A water leakage detection device for a mains water supply (2) into a premises connected to a water distribution system (4) within the premises, the device allowing the selective closure of the water supply to the premises and said device includes a sensor (8) which senses the flow of water through the distribution system and at least one valve (10) which can be controlled to close or reduce the water supply to the supply system, and control means (12) which allow the selective closure of the said valve in response to the sensor and characterised in that the control means allow the selection of the activation of the device and the said valve (10) is held in a normal, open position, when inactive and, when active, the valve remains in the open position when no water flow is detected by the sensor, or when water flow is detected at an authorised time or below a preset fluid flow level, said valve being moved to a closed position when water flow is detected at an unauthorised time or above a preset fluid flow rate by the sensor. A leakage detection device according to claim 1 wherein the control valve is fitted at the interface between the mains water supply and the distribution system and communicates with a number of flow sensors located throughout the distribution system. A leakage detection device according to claim 1 wherein the device is used on a mains water supply system to control the mains supply to a number of different premises and to sense the supply of fluid to any of a number of premises. A leakage detection device according to claim 1 wherein one or more valves are provided to control the fluid supply system. A leakage detection device according to claim 1 wherein at least one of the valves is fitted at the mains inlet. A leakage detection device according to claim 5 wherein the at least one control means is remote from the mains inlet. A leakage detection device according to claim 1 wherein when the device is activated, and the at least one sensor does not sense any fluid flow, the at least one valve is retained in an open position A leakage detection device according to claim 1 wherein when the at least one sensor is activated and detects a fluid flow, the at least one sensor causes the corresponding at least one valve to move to a closed position to prevent further fluid flow. A leakage detection device according to claim 8 wherein the control means is set to move the at least one valve from an open to a closed or partially closed position upon the detected fluid flow rate reaching a predetermined fluid flow rate. A leakage detection device according to claim 9 wherein when a flow rate which exceeds the pre-set level is detected, the sensor activates the at least one valve and closes the fluid supply. A leakage detection device according to claim 9 wherein when a flow rate which exceeds the pre-set level is detected, the sensor activates the at least one valve to move it to a position to reduce the flow rate to below the pre-set level. A leakage detection device according to claim 1 wherein the parameters for the control means are set by the user and can be activated/deactivated as often as required. A leakage detection device according to claim 12 wherein time periods during which fluid flow is permitted can be input into the control means. A leakage detection device according to claim 13 characterised in that when the control means is set at an off or noncontrolling state the at least one valve remains in an open position. A leakage detection device according to claim 13 wherein if fluid flow is sensed when the control means is active and is therefore outside the predetermined fluid flow time, or exceeds the predetermined fluid flow time, the valve is moved to a closed position. A leakage detection device according to any preceding claim wherein if no fluid flow is sensed the device is effectively disabled in an open position, until fluid flow is detected. A leakage detection device according to claim 16 wherein once a flow rate is detected, the detection device is re-activated. A leakage detection device according to any preceding claim wherein the control means has a signalling means to alert the user to any, or any combination of, fluid flow has been detected at an unauthorised time, or at an unauthorised level and the valve has been closed; that a power supply to the device has failed or is decreasing, in which case the device goes to a failsafe closed position. A leakage detection device according to any preceding claim wherein the device is connected to an alarm to sound in the event of a leak. A leakage detection device according to any preceding claim wherein the control means is connected to, integrated with or controlled via a personal computer. A leakage detection device according to any preceding claim wherein the device uses telemetry whereupon no wiring is required between the control means, the one or more sensors and/or the one or more valves. A leakage detection device according to any preceding claim wherein the device has wiring between the control means, the one or more sensors and/or the one or more valves.

Inventors: FOX ALAN, FOX, ALAN, FOX TECHNOLOGIES LTD.
Applicants: FOX TECHNOLOGIES LTD, FOX TECHNOLOGIES LTD.
Application year: 1999
Main classification: G01M3
IPC codes: G01M3