GB2179425A - A valve - Google Patents

Abstract

For use in a domestic water system, a valve has a flow passage (6) closure member (8) which is normally held in valve-open position. A control means, including a timer (22), is responsive to flow through the flow passage and if flow continues for a predetermined time this control means operates to release the closure member to close the flow passage. The control means also includes a solenoid (20), the plunger (26) of which normally holds the closure (8) open but is actuated by the timer (22) to release the closure (8), and a reed switch sensor (24) activated by the flow through the passage (6) and which triggers the timer (22) to begin its counting. A manual override to retain the closure (8) open comprises a pin (32, Fig. 1). <IMAGE>

Description

SPECIFICATION A valve This invention relates to a valve, and particularly, although not exclusively, to a valve for limiting flooding caused by burst pipes in domestic water systems.

If a pipe in a domestic water system bursts, for example as a result of freezing or of a fire, catastrophic damage can be caused by the escaping water. This is so particularly if the leakage occurs when the house is unoccupied, since large quantities of water can be discharged, causing serious damage to decorations and furnishing.

According to the present invention there is provided a valve comprising a flow passage and a closure member for closing the flow passage, the closure member being controlled by control means which is responsive to flow through the flow passage, the control means, in operation, causing the closure member to close the flow passage after continuous flow through the flow passage for a predetermined time.

The predetermined time would normally be somewhat greater than the maximum time during which flow would occur during normal circumstances. When used in a domestic water system, a valve in accordance with the present invention may be set so that the predetermined time is, for example, approximately 5 to 10 minutes, this being the maximum time for which most domestic appliances require a continuous flow of water. Where continuous flow for longer periods is required, for example when using a hose pipe or spinkler, a manually operable override mechanism may be provided for holding the valve open.

In a preferred embodiment, the closure member is spring loaded towards the closed position, and the control means has a displaceable member for retaining the closure member in the open position in normal conditions.

When flow continues for longer than the predetermined time, the displaceable member is withdrawn to allow the closure member to close the flow passage. The control means may comprise a timer which is reset to zero each time flow in the flow passage ceases, and which begins counting whenever flow commences. The control means may also be adapted to be reset to zero not only when flow ceases, but also when the flow rate varies. For example, if water begins to be drawn from one appliance, and subsequently begins to be drawn from another appliance, the counter will be reset in response to the increased flow which will occur when the second appliance begins to draw water.

For a better understanding of the present invention, and to show how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a perspective view of a valve; Figure 2 is a plan view of the valve of Fig.

1 with the cover removed, Figure 3 is a view taken in the direction of the arrow Ill in Fig. 2; and Figure 4 is a view taken in the direction of the arrow IV in Fig. 2.

The valve shown in the Figures comprises a valve block 2 and a cover 4, which may be transparent. The cover 4 is omitted from Fig.

2.

The block 2 has a flow passage 6 which is tapped at both ends to receive pipe unions so that the valve can be fitted in a domestic water pipe. The flow passage 6 has a closure member 8 in the form of a gate mounted on a stem 10. The gate 8 is biassed downwardly (into the closed position) by a compression spring 12. The stem 10 projects through a fitting 14 which is screwed into the block 2 and is provided at its upper end with a knob 16. The stem 10 has an anular recess 18 near the knob 16, and a further annular recess (not shown), in the region which is surrounded by the spring 12 in the position shown in Figs. 3 and 4. Control means for the gate valve 8 is provided on the block 2, and comprises a solenoid 20, a timer 22 and a sensor 24. The solenoid 20 has a plunger 26 which is biassed by a spring 28 towards the stem 10.When the solenoid is actuated, the plunger 26 is retracted against the pressure of the spring 28. The timer 22 is connected by a lead 30 to the sensor 24, which may comprise a reed switch.

In use, the valve shown in the Figures may be connected, for example, in line with an outlet pipe from a domestic water storage tank. The valve may, however, be fitted at other locations, for example in the supply to the tank. Furthermore, several valves may be provided in different parts of the water supply system.

To set the valve, the knob 16 is raised to open the valve by lifting the gate 8. The gate 8 is then retained in the open position by the plunger 26. If a tap which is supplied by water flowing through the valve is opened, the sensor 24 is activated and feeds a "start" signal to the timer 22, which then begins to count. When the tap is closed again, and flow through the passage 6 ceases, the absence of flow is sensed by the sensor 24, and the timer is reset to zero. However, if flow through the passage 6 continues, for example if the pipework downstream of the valve springs a leak, the timer 22 will continue to count until it reaches a preset value, at which point it delivers a signal which causes the solenoid 20 to be energised, so withdrawing the plunger 26 against the pressure of the spring 28.This allows the gate 8 to close, so shutting off the supply of water to the leak, and thus minimising damage which otherwise be caused by the escaping water.

Should it be necessary to keep the valve open for long periods, for example when supplying a hose, the pin 10 can be locked in the raised position by means of a screw 32 which is displaceable along a slot 34 in the cover 4.

Also, means for manually resetting the timer may be provided.

The timer may be adjustable so that the predetermined time can be set to suit the normal requirements of the system in which the valve is fitted.

The solenoid 20 and the timer 22 would normally be connected to the mains electrical supply, but a back-up supply is preferably provided by a battery so that the valve would operate reliably even in the event of power failure.

Although the valve shown in the drawings has been described by reference to a domestic water supply, it will be appreciated that the valve may be suitable for other purposes where a normally open valve is to be closed after continuous flow has occurred through it for a predetermined time.

By way of example, the valve shown in the drawings may be 100 mm square by 75 mm high.

Claims (12)

1. A valve comprising a flow passage and a closure member for closing the flow passage, the closure member being controlled by control means which is responsive to flow through the flow passage, the control means, in operation, causing the closure member to close the flow passage after continuous flow through the flow passage for a predetermined time.

2. A valve as claimed in claim 1, wherein the closure member is spring loaded towards the closed position, and the control means has a displaceable member for retaining the closure member in the open position in normal conditions, the control means withdrawing this displaceable member to allow the closure member to close the flow passage if flow continues for longer than the predetermined time.

3. A valve as claimed in claim 1 or 2, wherein the control means comprises a timer which is reset to zero each time flow in the flow passage ceases, and which begins counting whenever flow commences.

4. A valve as claimed in claim 3, wherein the timer is additionally reset to zero if the flow rate changes to another flow rate.

5. A valve as claimed in claim 3, wherein the timer is additionally reset to zero if the flow rate increases.

6. A valve as claimed in any one of claims 3, 4 or 5 each as appendant to claim 2, wherein said displaceable member is a plunger of a solenoid, the plunger being spring loaded to engage the closure member to hold the closure member in valve-open position, the timer if allowed to run for said predetermined time serving to actuate the solenoid to move the plunger to release the closure member to close the valve.

7. A valve as claimed in any one of claims 3 to 6, wherein the timer is adjustable so that said predetermined time can be of a selected length.

8. A valve as claimed in any one of claims 3 to 7, wherein the sensor is a reed switch connected to trigger the timer to being to count when a flow of fluid through the fluid passage commences.

9. A valve as claimed in any one of the preceding claims and comprising a manually operable override means for holding the valve open for longer than said predetermined time.

10. A valve as claimed in claim 9, wherein the override means comprises a lock member that can be moved to engage the closure member to hold the closure member locked in valve-open position.

11. A valve as claimed in claim 9 as appendant to any one of claims 3 to 8, wherein the override means is a means for manually resetting the timer.

12. A valve substantially as hereinbefore described with reference to the accompanying drawings.