GB2297382A - Overflow control system - Google Patents

Description

OVERFLOW CONTROL SYSTEM This invention relates to overflow control systems for liquid storage e.g. water storage tanks including W.C.

cisterns.

In typical water storage tanks, the normal water level is maintained by a float controlled valve. Problems often arise, either with the float, or the valve, resulting in the valve not fully closing and thereby causing the water to rise above its normal level and overflow through an overflow pipe. If unchecked, the overflowing water can cause flooding damage. Furthermore, this waste of water is undesirable and, where the water supply is metered, this can result in a significant expense.

An object of the invention is to provide an overflow control system in which overflowing water is prevented in a simple and effective manner.

According to the invention, an overflow control system for a liquid storage tank of the kind comprising a float arranged to control a valve in the liquid supply line comprises a collecting vessel for receiving overflow liquid from the storage tank, and a further valve in the liquid supply line downstream of the float controlled valve, said vessel being mounted to move under increased weight caused by overflow liquid to close said further valve.

Conveniently, switch means may be provided arranged to be operated by said vessel when said further valve is fully closed to activate an alarm.

Said vessel may be mounted internally of said storage tank, in which case liquid overflow through the normally provided overflow outlet would cease after closure of said further valve, when the overflow level drops.

Alternatively, said vessel may be mounted externally and connected to the normally provided overflow outlet, in which case a branch line may be provided through which overflow liquid can pass after the collecting vessel has been filled and prior to the overflow level dropping after closure of said further valve.

Preferably, the collecting vessel is mounted on a lever connected to a spindle for the further valve member, whereby movement of the vessel causes pivotal closing movement of said valve member.

Conveniently, when mounted externally said collecting vessel may have draining means for resetting the system.

Also, the collecting vessel may be locked after use with said further valve in at least a partly open position to permit liquid flow to the tank prior to repair of the float controlled valve.

In order that the invention may be readilly understood, two embodiments of overflow control system in accordance therewith will now be described with reference to the accompanying drawings in which: Figure 1 is an enlarged section of an external overflow connection to a water storage tank according to a first embodiment, Figure 2 is a general perspective view of part of the storage tank showing the components of the control system, Figure 3 is an enlarged view of the components of the control system, and Figure 4 is a section through a W.C. cistern with an internally mounted overflow system according to a second embodiment.

Referring to Figure 1, in the first embodiment, the tank 1 is provided with an overflow aperture 2 to which an overflow connection 3 of the externally mounted overflow system is sealingly attached via a rubber grommet 4. The connection 3 comprises an elongate chamber 5 which extends vertically and has an open top over which a cap 6 can be fitted. The cap carries a fly net 7 which can thus be removably seated in the chamber to filter overflow water.

The chamber 5 has an open bottom end 8 of reduced diameter and a side branch 9 comprising an overflow pipe 10.

Alternatively, the side branch 9 provides a connection for a separate overflow pipe.

Referring now to Figure 2, the system components are conveniently externally mounted on one end wall of the tank 1 and comprise, in addition to the mains water pipe 11 and main flow valve 12 normally provided, a further valve 13 (preferably of the known "Ballofix" type) in the pipe 11 downstream of the main flow valve 12, a collecting vessel 14 connected to the valve 13 via a lever 15, and a microswitch 16.

Referring also to Figure 3, the water vessel 14 is shown dotted in its inoperative state and in solid lines in its operative state. It can be seen that the vessel 14, via the lever 15, rotates an operating spindle 17 for the further valve 13 through approximately 600 between its fully open to fully closed condition (which is the usual arc of travel for a Ballofix valve). The vessel 14 has an opening 18 in its upper end which is connected via a flexible tube 19 to the bottom end 8 of the chamber 5; to accomodate pivotal movement of the. vessel, the tube is telescopic. The vessel 14, in its operative position, contacts the low voltage microswitch 16, which in turn activates a warning light 20 and/or audible alarm.A drain plug 21 is provided at the bottom of the vessel, and a locking pin 22 is associated with the lever 15 and a lug 23 on the housing of the further valve 13 for a purpose discussed below.

In operation of the system, overflow water from the tank enters the chamber 5 and initially passes via the tube 19 into the vessel 14. As it fills up, the vessel increases in weight and acts to pivot the lever 15 downwardly, and hence cause the further valve 13 via spindle 17 to rotate towards its closed position. When the vessel is filled completely, the further valve 13 cuts off the supply of mains water in the supply pipe 11 downstream of the main valve 12; the vessel also presses down on the microswitch 16 to close its contacts and activate the visual and/or audio alarm 20 to indicate that water is overflowing. Also the overflowing water is diverted through the branch line 9 until the overflow level drops.

The main float and its valve can thus be immediately inspected and repaired or, if repair is to be delayed, the vessel 14 can be pivoted to an intermediate position (as shown in Figure 2) and locked by inserting the locking pin 22 through aligned apertures in the lever 15 and lug 23.

It will be noted from Figure 2 that in the locked position, the further valve 13 is half-open to reduce the mains flow pressure to the tank and thereby reduce the overflow rate through the branch line 9 whilst awaiting repair.

When the repair has been completed, the vessel 14 can be drained via plug 21 and reset in its inoperative position.

Referring to Figure 4, the second embodiment comprises a W.C. cistern 24 containing, as known per se, a float 25 connected via an arm 26 to a valve 27 fitted to the upper end of a vertical water supply pipe 11, a vertical overflow pipe 29 and a cistern siphon 30, said pipes and siphon extending through sealed apertures 28 in the bottom wall of the cistern.

In accordance with the invention, an internally mounted overflow system is provided which, however, is basically similar to the externally mounted system of the first embodiment and like parts are given the same references. Thus, the system comprises a collecting vessel 14 connected via a lever 15 to the spindle 17 of the further valve 13 mounted in the water supply pipe 11 downstream of the float valve 27. Due to the internal mounting, an overflow chamber is not required. Instead, it will be noted that the collecting vessel 14 is elongated so as to project above the normal water level of the cistern to a height just below the height of the overflow pipe 29, and a support lever 31 is pivoted between the upper end of the collecting vessel 14 and the supply pipe 11.

Thus, in operation, if the float valve 27 fails to close, overflow water will enter the collecting vessel 14 until the combined weight of the vessel and its contents overcome the flotation effect of the water in the cistern 24, thereby causing downward movement of the vessel to close the further valve 13 via the lever 15. As with the first embodiment, the valve 13 can be set in a half open position; in this embodiment by fitting a locking pin 22 through aligned apertures in the support lever 31 and a lug 32 attached to the supply pipe 11.

Claims (10)

1. An overflow control system for a liquid storage tank of the kind comprising a float arranged to control a valve in a liquid supply line, further comprising a collecting vessel for receiving overflow liquid from the storage tank and a further valve in the liquid supply line, said collecting vessel being mounted to move under increased weight caused by overflow liquid to close said further valve.

2. A system according to Claim 1, wherin said further valve is located downstream of the float controlled valve.

3. A system according to Claim 1, or 2, wherein switch means are provided arranged to be operated by said collecting vessel when said further valve is closed to activate an alarm.

4. A system according to claim 1, 2 or 3, wherein said collecting vessel is mounted externally of the storage tank and connected to the normally provided overflow outlet, and wherein a branch line is provided upstream of the collecting vessel through which overflow liquid can pass after the collecting vessel has been filled and prior to the overflow level dropping after closure of said further valve.

5. A system according to Claim 4, wherein said collecting vessel has draining means for resetting the system.

6. A system according to Claim 4, or 5, wherein the collecting vessel has associated lock means for locking said further valve in at least a partly open position after use to permit liquid flow to the tank prior to repair of the float controlled valve.

7. A system according to Claim 1, 2, or 3, wherein said collecting vessel is mounted internally of said storage tank and has an inlet above the normal overflow outlet of the storage tank, the arrangement being such that, in use, any liquid overflow through said overflow outlet will cease after the overflow level drops as a result of closure of said further valve.

8. A system according to any one of the preceding Claims, wherein the collecting vessel is mounted on a lever connected to a valve spindle of the further valve, the arrangement being such that movement of the vessel causes pivotal closing movement of a valve member via said spindle.

9. A system according to Claim 8, wherein said further valve is of the Ballofix" type.

10. An overflow system substantially as hereinbefore described with reference to Figures 1 to 3, or Figure 4, of the accompanying drawings.