The present invention relates to a device for detecting and preventing water leaks. Most buildings are supplied with a mains pipe supplying water to the house. A master water cock is usually provided to turn the supply of water on and off in the building. If there is a leak in the building, this can lead to damage to the fabric of the building and its contents, and often the leak is not detected until considerable damage has been down. For example a leaking pipe buried under a floor may go unnoticed for many days or even weeks.

Similar problems occur in delivering fluids (such as gas, oil or other fluids) to or around building or plants. The invention seeks to provide a solution to this problem.

According to the present invention there is provided a device for detecting and preventing fluid leaks in a fluid circuit connected to a supply of fluid comprising: a) a fluid flow sensor, and

b) a controller connected to the fluid flow sensor to generate an alarm signal when fluid flow sensor senses flow in the circuit for more than a predetermined period of time.

Alarm signal may be connected to an audible alarm to allow a user to turn off supply of fluid to a circuit. The device may further include a stop cock having a first closed position to prevent flow of fluid through the circuit from a supply of fluid and a second normally open position to allow flow of fluid through the circuit from a supply of fluid. Generation of the alarm signal may control the stop cock to the first closed position.

In one embodiment the flow sensor is an impeller. The impeller may include a magnet on each impeller blade which rotate past a coil to generate an electrical pulse to sense fluid flow. Alternatively the flow sensor may include an arm in a fluid flow path connected to a strain gauge.

The stop cock and controller and fluid flow sensor may be mounted in a common housing. The housing may have an inlet to connect to a supply of fluid and an outlet to deliver fluid to a fluid circuit,

The controller may include a first component connected to the fluid flow sensor which transmits data wirelessly or through a wire to a second component. The controller may include a screen to display information.

Preferably the stop cock is motorised valve or solenoid-operated valve.

The fluid may be a gas or liquid.

The fluid may be water and circuit a water circuit in a building, and the supply of fluid may be mains water. The housing may include connectors to connect the housing inlet to a supply of fluid and the housing outlet to a fluid circuit. In a further embodiment, According to the present invention there is provided a device for detecting and preventing fluid leaks comprising:

a) a housing having an inlet to connect to a supply of fluid and an outlet to deliver fluid to a fluid circuit,

b) an electrical stop cock in the housing having a first closed position to prevent flow of fluid through the housing and a second normally open position to allow flow of fluid through the housing, and

c) a controller and at least one pressure sensor to operate the stop cock to the first closed position when pressure sensor senses the pressure in the circuit falls for more than a predetermined period of time.

The controller and at least one pressure sensor may comprise:

d) at least one pressure sensor to sense the pressure in the fluid circuit,

e) means to memorise the fluid pressure in the fluid circuit when no fluid is passing therethrough to provide a control fluid pressure value,

f) control means to turn the stop cock to the first closed position when the pressure sensor senses the pressure in the circuit remains below the control fluid pressure value after a predetermined period of time, and

g) alarm means to generate an alarm signal when the when a pressure difference exists across said stock cock after a predetermined period of time.

Preferably the stop cock is motorised valve or solenoid-operated valve. Preferably the housing includes a section of pipe containing said stop cock and pressure sensors. The fluid may be a gas or liquid.

The fluid may be water and circuit a water circuit in a building.

The housing may include connectors to connect the housing inlet to a supply of fluid and the housing outlet to a fluid circuit.

The invention will now be described with reference to the accompanying drawings showing schematic views of two embodiments. Referring to Figure 1 there is shown a device 1 for detecting and preventing fluid leaks.

Device 1 has a housing 10 containing a fluid flow sensor 20, a controller 30 connected to the fluid flow sensor 20 to generate an alarm signal when fluid flow sensor senses flow in the circuit for more than a predetermined period of time, and a stop cock 40. A pipe SO has an inlet 51 with suitable connectors 51 A (such as compression joints) to connect to mains water and an outlet 52 with suitable connectors 52A (such as compression joints) to connect to a water circuit in a building. The water circuit will typically have taps, showers, baths and water tank valves etc. which operate from time to time so that water will flow into the circuit from the mains. Stop cock 40 is a motorised valve or solenoid-operated valve 42 with a rotatable disc 41. Stop cock 40 has a first closed position to prevent flow of water through the pipe 50 into the building circuit from the mains and a second normally open position to allow flow of fluid through the pipe 50. Generation of the alarm signal controls the stop cock to the first closed position.

Flow sensor 20 is an impeller 21 in a sensor housing 22. The impeller 21 may include a magnet 24 on each impeller blade 23 which rotates past a coil 25 to generate an electrical pulse to sense fluid flow.

The controller 30 includes a first component 31 connected to the fluid flow sensor coil 25 which transmits data wirelessly (e.g. using Bluetooth) or through a wire to a second remote component 32. The controller 32 may include a screen 33 to display information, control buttons 34, and a loudspeaker 35.

Device 1 operates as follows.

The stop cock 40 provided by disc 41 is normally open. When no taps, showers, baths and water tank valves etc. are operated no water will flow through the flow sensor 20.

If a tap is operated, water will flow through the flow sensor 20 rotating impeller 21 with the magnets generating a pulse in the coil 25. The controller 30 will sense the flow through sensor 20. If the controller senses the flow for more than a predetermined period of time, it will generate an alarm signal. The predetermined period of time might be set at 15 minutes, the maximum time it takes to run a bath for example. Under normal circumstances alarm signal will not be generated as no taps, showers, baths and water tank valves etc. are operated for more than the predetermined period of time. If taps, showers, baths and water tank valves etc. are not turned off and hence operated for than the predetermined period of time, the controller will generate an alarm signal which will turn off the stop cock 40 to the first position to prevent water entering passing through pipe 50. This will prevent baths or basins form over-flowing by a user accidently failing to turn off a tap for example.

If taps, showers, baths and water tank valves etc. are not being used and there is a leak in the water circuit, the impeller will rotate (albeit possible very slowly), and the control circuit will, after the predetermined period of time, generate an alarm signal which will turn off the stop cock 40 to the first position to prevent water entering passing through pipe 50.

If desired a drip tray 60 could be provided under housing 10 to sense through a sensor 61 connected to controller 30 the presence of water in tray 60 which could result in a leak in the housing 10 which does not lead to the impeller rotating, e.g. a leak in the connection 51 A to the water mains.

The alarm signal may also generate an audible alarm through loudspeaker 35 in second component 32. Screen 33 in component 32 may be used display control messages relating to operation of the controller and also flow rates of water in pipe 50, and buttons 34 may be provided to set up the controller. The invention has uses in residential and commercial building to monitor for water leaks which may cause damage. However it may also be used to monitor circuits involving other fluids such as gas oil and chemicals in building, plant and machinery, oil rigs and the like. The invention may take a form different to that specifically described above. For example the stop cock could be a manual stop cock and the alarm signal may be connected to generate an audible alarm to allow a user to turn off supply of fluid to a circuit. Instead of an impeller, the flow sensor may include an arm in a fluid flow path connected to a strain gauge.

In an alternative embodiment, and referring to Figure 2, there is shown a device 1 for detecting and preventing fluid leaks.

A housing in the form of a pipe 10 is having an inlet 11 to connect to a supply of fluid such as a mains water supply A and an outlet 12 to deliver fluid to a fluid circuit such as a water circuit in a building. A suitable connector such as a compression joint 11A is provided to connect the pipe 10 to a mains supply, and a compression joint 12A is provided to connect the pipe 10 to the water circuit B. An electrical stop cock in the form of a rotatable disc 20 is provided in pipe 10 in the pipe having a first closed position to prevent flow of fluid through the pipe and a second normally open position to allow flow of fluid through the pipe. Disc 20 may be rotated by a motor or solenoid 21

A controller and at least one pressure sensor to operate the stop cock to the first closed position when pressure sensor senses the pressure in the circuit falls for more than a predetermined period of time.

The controller and at least one pressure sensor comprises a pressure sensor 30 and reader 31 to sense the pressure in the fluid circuit. Memory means 40 memorises the fluid pressure in the fluid circuit when no fluid is passing therethrough to provide a control fluid pressure value, normally mains water pressure at any one time. Control means in the form of Comparator 50 and timer 60 turns the stop cock to the first closed position when the pressure sensor senses the pressure in the circuit remains below the control fluid pressure value after a predetermined period of time. An alarm means 70 generate an alarm signal when the when a pressure difference exists across said stock cock after a predetermined period of time.

Device 1 operates as follows.

The stop cock provided by disc 20 is normally open. Assuming no water is flowing through the circuit B, i.e. no taps, showers, or other water appliances are running, the pressure in the water circuit is equal to mains pressure A. Pressure sensor 30 measures this pressure and this is memorised in memory means 40 to provide a control fluid value. If a tap is operated, the pressure in the water circuit will fall below the control fluid pressure value and this is measured by the comparator 50. If the tap is then closed the pressure in the water circuit will rise back to below the control fluid pressure value. Provided the water pressure falls only for a predetermined period of time as set by the timer 50, the water circuit operates as normal. The predetermined period of time might be set at 15 minutes, the maximum time it takes to run a bath for example.

If the tap is operated and not closed by mistake, the pressure in the water circuit will fall, and after the predetermined period of time the disc will be turned to the first closed position by motor or solenoid 21. Alarm 70 will be operated to alert the user of the water circuit.

If all the taps and other water appliances are not being used and there is a leak in the water circuit, , the pressure in the water circuit will fall, and after the predetermined period of time the disc will be turned to the first closed position by motor or solenoid 21. Alarm 70 will be operated to alert the user of the water circuit.

The invention has uses in residential and commercial building to monitor for water leaks which may cause damage. However it may also be used to monitor circuits involving other fluids such as gas oil and chemicals in building, plant and machinery, oil rigs and the like.

Whilst only one pressure senor is described in the drawing, it may be possible to use more than one pressure sensor or an alternative arrangement to that shown in the drawing to provide a control means to turn the stop cock to the first closed position when the pressure sensor/s senses the pressure in the circuit remains below the control fluid pressure value after a predetermined period of time, and to provide an alarm means to generate an alarm signal when the when a pressure difference exists across said stock cock after a predetermined period of time. The invention may take a form different to that specifically described above. For example, an override switch may be provided so that the fluid can be turned on even if a leak remains undetected. It may also be possible to use several devices of the invention in order to locate the position of a leak in a fluid circuit is, for example if one device was used for upstairs and one device downstairs in a house, or every ten miles in an oil pipe.

Further modifications will be apparent to those skilled in the art without departing from the scope of the present invention.