GB2310068A

GB2310068A - Fluid leak responsive shut off valve

Info

Publication number: GB2310068A
Application number: GB9603335A
Authority: GB
Inventors: Stephen John Chadwick
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-02-10
Filing date: 1996-02-10
Publication date: 1997-08-13
Also published as: GB9603335D0

Abstract

The valve B, C is provided in a body, through which fluid flows, together with a flow detector E, F. A controller G receives a signal from the detector and, in response to abnormal flow conditions indicative of a leak, causes the valve to shut off fluid flow. The controller may include programmable timing means to determine if there has been flow either greater than or less than a predetermined value sustained for more than a predetermined time. The value(s) of the predetermined flow and timing criteria may be automatically adjusted in response to changes in fluid movement measured over a time period. The sensitivity of operation of the valve may be inhibited or increased during certain periods of the day or week, the valve may also be closed in response to detection of freezing temperature. The device can be incorporated into the water system of a building although it is applicable to other fluid distribution systems.

Description

FLUID SHUT-OFF VALVE Introduction This invention relates to a device for controlling the flow of fluid in a conduit, and particularly to a device which can be incorporated in the water system of a building to shut off the water supply under certain conditions.

Premises which are left unattended for a period of time, particularly during cold weather, may suffer burst pipes or damaged plumbing fittings which results in considerable damage to the property as the water flow continues unchecked for a long period of time. It is the object of this invention to provide a device which enables this problem to be alleviated.

The example used in the introduction relates to water flow in a premises, though it will be applicable to other fluids in other distribution systems or networks.

According to the present invention there is provided a device for controlling flow of fluid in a conduit, having means for detecting flow of said fluid in a conduit; valve means operable to at least reduce said flow, and/or to shut off said flow, means for determining if said flow meets at least one predetermined criterion; and means for causing said operation of said valve means in response to said at least one criterion having been met.

One of such said criteria may comprise a flow greater than a predetrmined value and sustained for more than a predetermined time.

Another of such said criteria may comprise a flow less than a predetermined value, sustained for more than a predetermined time.

For example, in a domestic, commercial or industrial water system, the device can be set so that it will shut off the flow of water if it detects that there has been no fluid flow during a period of say 12 hours This condition indiates ihat the IJI UnliSCá ai t: unoccupied and it is therefore prudent to turn off the water.

Similarly, if the valve detects that there has been a continuously high flow rate through the valve for a pre-set period of say 20 minutes, this will cause the valve to shut off the water. This condition indicates the possibility of a burst pipe or faulty float valve in a storage tank or cistern for example, within the premises.

The valve means may comprise a valve member spring means biasing the valve member to a closed position relative to a passageway for said flow of fluid, catch means for holding the valve member in an open position relative to said passageway, and means for releasing said catch means for permitting the valve member to move to it's closed position under the action of the said spring biasing means.

The catch means may be adapted to be released by a solenoid The valve member may be manually settable to it's open position The means for detecting flow of fluid may comprise an element, moveable in response to flow of fluid, and transducer means providing an electrical signal idicative of said movement of fluid.

The device may comprise a valve body adapted for connection in said conduit, and comprising both said means for detecting the flow of fluid and said valve means.

The device may comprise an electronic controller including programmable timing means, and means for causing operation of said valve means in response to flow and measured time, meeting programmed values. The timing means may be manually adjustable The above mentioned valve and water flow detector may be housed in a single body, or may be each housed in separate bodies linked together.

The device may comprise a body in the form of a moulding, casting or stamping, with means of connecting inlet and outlet pipework, and housing a shut off valve, and housing also a water flow detector. Separate from or attached to the body, is an electronic controller which monitors the signal from the flow detector and which causes the valve to close under certain flow conditions.

Other features of the invention are described in the following specification, which by means of example, illustrates the device as envisaged for use in a domestic, commercial or industrial water system; Figure 1 shows a section of the device.

The cross-lined area represents the body ofthe device, within which water enters through inlet pipe (H). It flows into the valve chamber (B) shown open, and then to the paddle wheel. The flow causes the paddle wheel to rotate. The water then flows out of the body through the outlet pipe (I) The paddle wheel paddles have metallic or magnetic inserts which cause electrical pulses to be generated in the electronic sensor (F). These pulses are fed by wire to the input (J) ofthe controller (G).

The controller is a small electronic circuit which is pre-programmed to monitor the rate of flow of the water over time. If there is no flow, or low flow below a predetermind value over a long time period, called tl, which is set to say 12 hours, the controller signals to the valve to close.

Similarly if there is high flow for a shorter period, called t2, which is set to say 20 minutes, then the controller causes the valve to close.

A block diagram of the control function of the controller is shown in figure 2 The controller sends an electrical pulse signal to a solenoid (C) which temporarily withdraws a latch which allows the valve to close by the action of a spring (D) which shuts off the water flow.

The valve is re-opened by manually pulling the reset knob (A) so that the solenoid latch re-engages to hold the valve open.

The device as illustrated has been designed so that the solenoid is only energised for a short pulse when required to close. This reduces the electrical power requirement to a minimum and provides the option of powering the device by battery, as the electronic controller will require only very minimal power.

The paddle wheel type flow detector is only one option, other types of flow detector could be substituted, such as those which use pressure differential, or movement of a vane or ball (as in a non return valve).

Similarly, a standard solenoid could be used, i.e. one which is energised to open the valve, and de-energised to close the valve, if the device is required to operate fully automatically, i.e. without the need for a manual reset operation.

The diagram shows a plunger type shut off valve. A 'quarter-turn' valve would be equally applicable, where the valve is spring loaded so that it closes due to the force of the spring. The valve would be opened manually, and latched in the open position by the solenoid. It would then close due to the action of the spring when the solenoid is energised.

The invention as described may use very simple control algorithms, e.g.

1 If flow rate = 0 for period > tl then shut valve 2. If flow rate high for period > t2 then shut valve.

More sophisticated monitoring can be programmed in to the controller, such that it monitors a range of flow rates rather than just zero or low flow, and high flow.

The controller could be developed so that it 'self tunes' to the normal flow rates, and changes in flow rate for any particular installation by recording the changes in flow rate over a period of time and then automatically adjusting t 1 and t2.

Further options and facilities The shut off valve could be incorporated into a water meter. Thus the signal to the controller would be derived from the rotation of the water meter, and this would be fed back to close the solenoid valve as described above.

2 The device could accept inputs from a timer so that it only operates, or becomes ore sensitive, during certain periods of the day or week.

3 The device could accept inputs from a temperature detector, for example thermocouple or thermistor, so that the device shuts off the supply where there is risk of freezing.

4 The device could accept inputs from a photoelectric detector so that it only operates, or becomes more sensitive, during certain periods of the day.

5 The device could provide electrical outputs to; - Signal the state of the valve, open or closed.

- Signal the state of the batteries - Signal a proportional value for the current flow rate.

- (in the case of the water meter type) signal water consumption.

6 Low Battery(ies); When the charge in the battery becomes low the device could emit warning sound, for example a regular "beep", and/or light a warning lamp, and/or provide an output signal to be linked to a remote monitor.

The controller would give a pulse to the solenoid to close the valve before the charge in the batteries becomes too low.

7 A mains and rechargeable battery hybrid device would incorporate rechargeable batteries which are continually charged by a circuit in the controller. The mains would power a (separate) isolating transformer and rectifier providing the low voltage supply.

8 A solely mains powered unit would require no batteries. In this case the solenoid valve would be energised continually, and the controller would switch off the power to the solenoid when a leak is detected.

During mains failure the valve will therefore close. A manual over-ride device would be fitted so that the valve can be opened by operating a lever or plunger. This would latch in the open position, and remain latched until the power is restored. At this time, the valve would be held open by the electrical power, and the manual over-ride would automatically be un-latched so that in case of subsequent power failure, the valve will close.

9 The device could be made self-contained in that the rotation of the paddle wheel (flow detector) could be made to tum a generator or dynamo which could provide charge to the batteries.

10 The device could accept input(s) from remote moisture detectors, situated around the property in positions where water will flow following rupture of pipes or tanks. These could be linked directly by wires, or by remote telemetry to the device causing it to shut off the supply if water is detected.

Claims

1. A device for controlling flow of fluid in a conduit, comprising means for detecting flow of said fluid in the conduit; valve means operable to at least reduce said flow; means for determining if said flow meets at least one predetermined criterion; and means for causing said operation of said valve means in response to said at least one criterion having been met.

2. A device according to Claim 1 wherein said valve means is operable to shut off said flow

3. A device according to Claim 1 or Claim 2 wherein said criterion or one of said criterion or one of said criteria comprises a flow greater than a predetermined value and sustained for more than a predetermined time.

4. A device according to Claim 1 or Claim 2 wherein said criterion or one of said criteria comprises a flow less than a predetermined value, sustained for more than a predetermined time.

5. A device according to any of the preceding claims wherein said valve means comprises a valve member, spring means biasing the valve member to a closed position relative to a passageway for said flow of fluid, catch means for holding the valve member in an open position relative to said passageway, and means for releasing said catch means for permitting the valve member to move to it's closed position under the action of said spring biasing means.

6. A device according to Claim 5 wherein said catch means is adapted to be released by a solenoid.

7. A device according to Claim 5 or Claim 6 wherein said valve member is manually settable to it's open position.

8. A device according to any one of the preceding claims wherein said means for detecting flow of fluid comprises an element moveable in response to said flow of fluid, and transducer means providing an electrical signal indicative of said movement.

9. A device according to any of the preceding claims comprising a valve body adapted for connection in said conduit, and comprising both said means for detecting flow of fluid and said valve means

10. A device acording to any one of the preceding claims comprising an electronic controller including programable timing means and means for causing operation of said valve means in response to flow and measured time meeting programmed values

11. A device acording to any one of the preceding claims comprising an electronic controller having means for automatically adjusting the value or values of the predetermined fluid flow and timing criterion or criteria in response to the changes in said fluid movement measured over a period of time.

12. A device acording to any one of the preceding claims comprising a timing means which inhibits or increases the sensitivity of operation of said valve means during certain periods of the day or week.

13. A device according to any one of the preceding claims comprising a temperature measuring means which causes said valve means to move to a closed position when the measured temperature falls to a temperature that can cause the freezing of the said fluid.

14 A water supply system for a building, having a control device in accordance with any one of the preceding claims provided in an inlet pipe of the system.

15 A device, or a water supply system incorporating same, substantially as hereinbefore described with reference to the accompanying drawings.