GB2448342A

GB2448342A - Water supply system

Info

Publication number: GB2448342A
Application number: GB0707020A
Authority: GB
Inventors: Dennis Struthridge
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-04-12
Filing date: 2007-04-12
Publication date: 2008-10-15
Anticipated expiration: 2027-04-12
Also published as: GB2448342B; GB0707020D0; GB2448342B8

Abstract

A system (30) for supplying water to an installation that is sensitive to water pressure comprises; a first inlet for receiving water at a low pressure (e.g. a rainwater holding tank 12); a second inlet for receiving water (e.g. from a mains water supply 40) at a pressure higher than suitable for feeding to the installation; means for controlling the pressure of the water from the second inlet and for reducing the pressure of the water to a pressure suitable for feeding to the installation; an outlet for water to be supplied to the installation from either the first or the second inlet; and means for switching the flow of water to the outlet between the first and second inlet. The system is particularly suitable for use in supplying collected rainwater to a toilet cistern, especially in a domestic dwelling.

Description

SYSTEM FOR WATER SUPPLY

The present invention relates to a system for supplying water, in particular to a system for supplying water from a plurality of water sources at different pressures to a device sensitive to the pressure of supply. The present invention is especially concerned with the supply of water at a high or mains pressure and water from a low pressure source, such as recycled rainwater, to the cistern of a toilet or the like.

In a typical installation of a toilet, in particular in domestic toilet systems, water is supplied to the cistern of the toilet. A valve assembly is provided in the cistern to control the level of the water in the cistern and allow the cistern to refill to the appropriate level after each flush of the toilet. The most commonly used form of valve system for toilet cisterns, in particular for domestic installations, employs a float that is allows to rise and fall with the level of water in the cistern. The float is connected to a valve in the water supply line and operates to open and close the valve as the water level in the cistern rises and falls. A very common arrangement is to have the float in the form of a hollow sphere attached to one end of an actuating arm, the other end of which is pivoted at the valve to control the opening and closing of the valve as the float rises and falls. These valve assemblies are commonly known as ball valves'.

In the United Kingdom, water may be supplied to domestic toilet installations from one of a number of different sources. A first source of water supply is to feed water to the toilet cistern directly from the main water supply to the house or dwelling.

The mains water supply to a house or dwelling will typically be at a relatively high pressure, of the order of about 30 psi (about 2 bar) or higher. In such a case, the valve assembly installed in the cistern will be arranged to operate with a high water feed pressure. A second source of water supply is from a tank, typically situated above the toilet cistern, for example in the roof space or the like. While the tank is fed with water from a mains supply at mains pressure, the tank itself will feed water to the facilities in the house or dwelling at a much reduced pressure. The pressure of water supplied to a given installation, such as a toilet cistern, will depend upon the height difference between the installation and the tank, that is the head' of water. A typical supply pressure in such a case is of the order of about 5 to 10 psi (about 0.3 to 0.7 bar). In such a case, the valve assembly installed in the cistern of the toilet will be adapted to operate with a low pressure water feed.

In general, therefore, it is the case that a given toilet cistern will be fitted with a valve assembly specific to the pressure of the supplied water. A problem arises, therefore, when it is desired to change the water supply to one operating at a significantly different pressure. Such a change will necessitate changing or modifying the valve assembly in the cistern. The problem is particularly acute when it is desired to provide a toilet cistern with a plurality of alternative water supplies, operating a significantly different supply pressures.

This is a particularly major problem when considering using collected rainwater to flush a toilet, It would be most advantageous if a system could be found to allow rainwater to be gathered and used in a house or dwelling in situations where the high purity of mains supplied drinking water is not required. One such situation is the flushing of toilets. Rainwater collecting systems are known and generally comprise a means of gathering rainwater, such as guttering to collect rainwater from roofs, and a tank for storing rainwater. To be used, the rainwater must be stored in a tank at a sufficient height to provide water to the required location under gravity.

Alternatively, the rainwater may be stored in a tank at or near ground level and provided upon demand by a pump. In either case, the pressure of supply of rainwater will be relatively low.

The supply of low pressure rainwater to a toilet cistern is not a problem, as described hereinbefore. However, a problem does arise when the supply or rainwater is exhausted, for example during a period of drought or heavy usage. It is then required to switch the supply of water to the cistern from the rainwater supply to an alternative supply, such as mains water. As noted above, this would require replacing or modifying the existing valve assembly in the cistern to operate with a high pressure water supply. As the efficient use of collected rainwater relies upon being able to readily and repeatedly switch between different water supplies, a solution to this problem is required.

According to the present invention, there is provided a system for supplying water to an installation that is sensitive to water pressure, the system comprising: a first inlet for receiving water at a low pressure; a second inlet for receiving water at a pressure higher than suitable for feeding to the installation; a first means for controlling the pressure of the water from the second inlet and for reducing the pressure of the water to a pressure suitable for feeding to the installation; an outlet for water to be supplied to the installation from either the first or the second inlet; and means for switching the flow of water to the outlet between the first and second inlet.

The system is suitable for supplying an installation, such as the cistern of a domestic toilet, that requires water to be supplied at a low pressure. In this respect, low pressure is a reference to water at a pressure of from about 2 psi (about 0.1 bar) to about 15 psi (about 1.0 bar). In contrast, the mains water supply to properties is at a high pressure. In this respect, high pressure is a reference to water at a pressure of from about 15 psi (about 1.0 bar) to about 45 psi (about 3 bar) or higher.

The installation to be supplied with water is most preferably a toilet cistern, in particular a domestic toilet cistern The system of the present invention is used to supply water to an installation and allow the user to select from a high pressure supply, such as the mains water supply, or a low pressure supply, such as a supply of collected rainwater, as will be described hereinafter, which is at a low pressure, without the need to change or modify the valve assembly in the installation. The system is arranged such that the valve assembly of the installation is compatible with the low pressure water provided to the first inlet of the system. This water may be supplied directly to the installation.

Water from the second inlet is at a pressure higher than compatible with the installation. The pressure of this incoming water is reduced by a suitable means before being fed to the installation via the outlet of the system. The means for controlling the pressure of water may be any suitable means for reducing liquid pressure. Suitable means include a restriction, such as an orifice plate or the like, having a high pressure drop for liquid flowing through it. In use, water is caused to flow through the means and reduce in pressure. A most suitable means is a valve, which allows the reduction in water pressure to be adjusted and/or controlled, to meet the demands of the installation being fed. Suitable means, in particular suitable valves are well known in the art and commercially available.

The system further comprises means for switching between the low pressure water supply and the high pressure water supply. Suitable means are known in the art and are commercially available. A single valve may be employed, having a first position in which water from the low pressure inlet is allowed to pass to the outlet, and a second position in which water from the high pressure inlet, at a reduced pressure, is allowed to pass to the outlet. Alternatively or in addition, the means may comprise a valve on each of the low pressure inlet side and the high pressure inlet side, whereby when the supply of water needs to be switched, the appropriate one of the said valves is closed and the other of the said valves is opened. In such an arrangement, means may be provided to prevent both valves being open at the same time, in order to prevent water flowing in the reverse direction through one or other of the inlets.

In the case of a supply of high pressure water from a mains supply, it is preferred, and may be required, that means are provided to prevent the flow of water in the reverse direction, that is backflow, and thus prevent contamination of the water supply. As an example, the system may comprise a one-way valve or a vacuum breaker to prevent backflow along the high pressure inlet line. Suitable means are well known in the art and commercially available.

In a further aspect, the present invention provides a toilet system comprising a cistern having a valve assembly adapted to receive low pressure water and a system as hereinbefore described.

The system of the present invention is particularly suitable for the supply of collected rainwater to a toilet cistern, in particular a domestic toilet cistern.

Accordingly, a still further aspect of the present invention provides a collected rainwater toilet, comprising: a toilet cistern having a valve assembly adapted for receiving a low pressure supply of water; a vessel for holding collected rainwater; means for supplying rainwater from the vessel to the toilet cistern; means for supplying high pressure water for use in the toilet cistern; a system for selectively supplying water to the toilet cistern from one of the vessel or the means for supplying high pressure water, the system comprising: a first inlet for receiving water from the vessel; a second inlet for receiving water from the means for supplying high pressure water; a first means for controlling the pressure of the water from the second inlet and for reducing the pressure of the water to a pressure suitable for feeding to the cistern; an outlet for water to be supplied to the cistern from either the first or the second inlet; and means for switching the flow of water to the outlet between the first and second inlet.

The vessel for holding collected rainwater may be any suitable vessel, for example a tank or the like. The vessel is preferably located at a level above that of the toilet cistern, such that rainwater may be fed to the cistern under gravity.

Alternatively, the system may comprise a pump for delivering rainwater from the vessel.

Rainwater may be collected for holding in the vessel by any suitable means, such as conventional guttering to gather rainwater from a roof or the like.

The high pressure supply of water is preferably a mains supply of water, such as is available in a domestic building or the like.

The system for selectively supplying water from the vessel or from the high pressure supply is as hereinbefore described.

Embodiments of the present invention will now be described, by way of example only, having reference to the accompanying drawings, in which: Figure 1 is a schematic representation of a collected rainwater system for supplying water to a domestic toilet cistern; Figure 2 is a representation of a system for supplying water to the toilet cistern of Figure 1 according to a first embodiment of the present invention; and Figure 3 is a representation of a system for supplying water to the toilet cistern of Figure 1 according to a second embodiment of the present invention.

Referring to Figure 1, there is shown a rainwater collection system for supplying water to a domestic toilet cistern in a domestic dwelling, generally indicated as 2. The system 2 comprises means for gathering rainwater, in the form of guttering 4 of conventional design to collect rainwater from the roof 6 of the building.

Rainwater collected in the guttering 4 is fed to a collecting tank 8 via a downpipe 10.

A rainwater holding tank 12 is located in the roof space of the building. Rainwater is fed from the collecting tank 8 to the holding tank 12 by a pump 14 along line 16.

A toilet system 20 of conventional design is positioned on the lower floor of the dwelling below the holding tank 12. The toilet system 20 comprises a cistern 24 for holding water to be flushed into the toilet in conventional manner. The cistern 24 comprises a low pressure valve assembly 26 of conventional design for controlling the refilling of the cistern and the level of water in the cistern 24. A water supply system 30 controls the supply of water to the cistern, the details of which will be described hereinafter. The water supply system 30 receives water from two sources.

First, water is fed under gravity from the holding tank 12 to the low pressure inlet of the water supply system 30 along line 32. The valve assembly 26 in the cistern is adapted to receive water at the pressure supplied by the gravity feed from the holding tank 12. Second, water is supplied to the high pressure inlet of the water supply system 30 from a conventional mains water supply 40. The mains supply 40 provides water at mains pressure, significantly above the pressure acceptable for the valve assembly 26 in the cistern 24.

Referring to Figure 2, there is shown a first embodiment of a water supply system 26. The system comprises an inlet 102 for high pressure water, an inlet 104 for low pressure water and an outlet 106 for water to be supplied. The high pressure side of the system comprises a non-return or one-way valve 108 of conventional design, in order to prevent the backflow of water into the high pressure supply, possibly resulting in the contamination of the mains water supply. An isolation valve 110 is provided in the high pressure line, to enable the high pressure supply to be isolated if needed. A pressure control valve 112 is provided downstream of the isolation valve and is used to reduce the pressure of water in the high pressure line to pressure acceptable for feeding to the valve assembly in the cistern of the toilet.

Again, this valve may be of conventional design. The pressure control valve 112 is connected to one inlet of a three-way valve 114. The low pressure side of the system comprises an isolation valve 116 for isolating the low pressure supply, if required. Water from the low pressure side is fed to the second inlet of the three-way valve 114. The low pressure side may be provided with a non-return or one-way valve as included on the high pressure side, again to prevent the backflow of water into the low pressure system.

In use, the high pressure inlet 102 is connected to the mains water supply, while the low pressure inlet is connected to the supply of rainwater from the holding tank 12. When the holding tank 12 of Figure 1 contains sufficient water, the valve 114 is positioned to allow water to flow from the low pressure inlet 104 to the outlet 106. Should it be required to switch water supply to high pressure water, for example when the holding tank 12 is empty, the valve 114 is adjusted to close the supply of low pressure water and allow high pressure water from the high pressure inlet 102 to flow to the outlet 106. The pressure control valve 112 is set to reduce the pressure of the high pressure water to the required level. Once the pressure control valve 112 has been set, it is generally sufficient simply to operate the valve 114 to switch from one supply to another.

The operation of the valve 114 may be automated, for example by having a level detector in the holding tank 12 operable to move the position of the valve 114 when the level of rainwater in the holding tank falls below a preset minimum level.

Referring to Figure 3, there is shown an alternative arrangement for the water supply system 26. The system comprises inlets 202 and 204 for high and low pressure water and an outlet 206 for water to be supplied to the cistern of the toilet.

On the high pressure side, a non-return or one-way valve 208 is provided as described hereinbefore. A flow control valve 210 is provided to control the flow of high pressure water. A pressure control valve 212 downstream of the flow control valve is used to set the pressure of the water leaving the high pressure side of the system. On the low pressure side, a flow control valve 214 is provided to control the flow of low pressure water. Again, the low pressure side may be provided with a non-return or one-way valve as included on the high pressure side, to prevent the backflow of water into the low pressure system.

In use, the system of Figure 3 is connected as described above with respect to the system of Figure 2. The selection of water from the high pressure supply or the low pressure supply is made by the appropriate operation of the flow control valves 208 and 214. When switching supply, it is preferred that both valves 208 and 214 are closed, before the relevant valve is opened to provide the selected supply of water. Means may be provided to prevent both valves 208 and 214 from being open at the same time, which means are generally indicated by the dotted line 220.

Again, the operation of both flow control valves 210 and 214 may be automated, as described hereinbefore.

Claims

1. A system for supplying water to an installation that is sensitive to water pressure, the system comprising: a first inlet for receiving water at a low pressure; a second inlet for receiving water at a pressure higher than suitable for feeding to the installation; means for controlling the pressure of the water from the second inlet and for reducing the pressure of the water to a pressure suitable for feeding to the installation; an outlet for water to be supplied to the installation from either the first or the second inlet; and means for switching the flow of water to the outlet between the first and second inlet.

2. The system according to claim 1 wherein the installation is a toilet cistern.

3. The system according to claim I or 2, wherein the means for controlling the pressure of water from the second inlet comprises a valve.

4. The system according to any preceding claim, wherein the means for switching the flow of water is a single three-way valve.

5. The system according to any of claims 1 to 3, wherein the means for switching the flow of water comprises a valve for controlling the flow of low pressure water and a valve for controlling the flow of high pressure water.

6. The system according to claim 5, wherein means are provided to prevent both the said valves being open at the same time.

7. The system according to any preceding claim, further comprising means for preventing the backflow of water into the high pressure supply.

8. The system according to any preceding claim, further comprising means for preventing the backflow of water into the low pressure supply.

9. A toilet system comprising a cistern having a valve assembly adapted to receive low pressure water and a system for supplying water to the cistern according to any preceding claim.

10. A collected rainwater toilet system, comprising: a toilet cistern having a valve assembly adapted for receiving a low pressure supply of water; a vessel for holding collected rainwater; means for supplying rainwater from the vessel to the toilet cistern; means for supplying high pressure water for use in the toilet cistern; a system for selectively supplying water to the toilet cistern from one of the vessel or the means for supplying high pressure water, the system being as claimed in any of claims 1 to 8.

11. A system for supplying water substantially as hereinbefore described having reference to any one of Figures 1 to 3.

12. A collected rainwater toilet system substantially as hereinbefore described having reference to any one of Figures 1 to 3.