GB2349908A

GB2349908A - Water supply arrangement

Info

Publication number: GB2349908A
Application number: GB9905894A
Authority: GB
Inventors: Stephen John Elsey
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-03-16
Filing date: 1999-03-16
Publication date: 2000-11-15
Anticipated expiration: 2019-03-16
Also published as: GB9905894D0; GB2349908B

Abstract

A water supply arrangement for a domestic dwelling includes a cold water inlet pipe 10 for cold water drawn from a mains supply, a relatively large volume accumulator 17 connected through a check valve 16 to the inlet supply pipe and a cold water delivery pipe system 15 leading from the accumulator to the cold water taps 19 of the dwelling. The diameter of at least the majority of the pipes in the cold water delivery pipe system 15 is greater than the diameter of the cold water inlet pipe 10 leading to the accumulator 17. Further, the cold water delivery pipe system supplies cold water to a hot tank 22 feeding hot water to a hot water delivery pipe system 30, at least the majority of the pipes in the hot water delivery pipe system being greater than the diameter of the cold water inlet pipe. The cold water inlet pipe may instead supply a cold tank 36 from which water is delivered to the cold water delivery pipe system 15 by a pump 38, the accumulator 17 being connected into that system downstream of the pump.

Description

Ref. 11 Wsp -1- 2349908 WATER SUPPLY ARRANGEMENTS This invention relates

to a water supply arrangement for a domestic dwelling and in its preferred aspects to a water supply arrangement which delivers both hot and cold water to taps distributed within the dwelling.

A conventional water supply arrangement for a domestic dwelling has a cold water storage tank disposed in the roof space, and which is filled to a predetermined level from a mains supply, by way of a ball-valve which admits water into the tank as water is drawn therefrom. A cold water supply system feeds the taps around the dwelling from the tank, and hot water is supplied from a hot tank, which latter also draws cold water from the tank in the roof space.

Though the above water supply arrangement has been used very widely in domestic dwellings, there is a tendency to install mains water pressure systems in view of certain disadvantages of the conventional arrangements. In particular, the pressure of the water delivered to the taps is limited to the head provided by the physical location of the tank in the roof space. A single cold water delivery pipe normally leads from the tank with individual pipes branching off that main pipe to the taps; the consequence is that the pressure and volume flow available from one tap depends upon whether other cold water taps have also been opened. A similar situation also occurs with the hot water system, though usually the hot tank has its own cold water feed pipe, from the cold water tank in the roof space.

A further disadvantage of the known arrangements is that algae, bacteria or other micro-organisms may start to multiply in the cold water tank Ref, 1 1642sp in the roof space and may produce toxic or other harmful products in the water delivered from the tank. To guard against this, there is now a recommendation that such cold water tanks should be disinfected at least annually, especially for public buildings. This problem does not arise with a mains water pressure delivery system as no cold water tank in the roof space is required.

A disadvantage of a mains pressure water delivery system is that the pressure and volume delivery is limited by the diameter of the incoming pipe from the external water main, as well as by the pressure in that main. Most domestic dwellings are provided with a 15 mm incoming mains water pipe, though of course older dwellings have pipes of imperial standards. In such a case, the volume flow which may be available for example at a bath, if both the hot and cold bath taps are turned on, may be somewhat restricted - and if then a further tap is turned on elsewhere, the flow rates from those taps will be even smaller.

The present invention aims to minimise the above effect on a mains water pressure delivery system and thus at ensuring an adequate flow is available at all taps connected to the system, even though one or more taps may simultaneously be turned on to deliver water.

According to one aspect of the present invention, there is provided a water supply arrangement for a domestic dwelling, comprising: a cold water inlet pipe for cold water drawn from a mains supply; an accumulator of a relatively large volume connected through a check valve to the inlet supply pipe; and a cold water delivery pipe system Ref.11642sp -3 leading from the accumulator to the cold water taps of the dwelling; in which water supply arrangement the diameter of at least the majority of pipes in the cold water delivery pipe system is greater than the diameter of the cold water inlet pipe leading to the accumulator.

In an alternative but closely related form of this invention, there is provided a water supply arrangement for a domestic dwelling, comprising: a cold water inlet pipe for cold water drawn from a mains supply and supplying cold water to a storage tank; an accumulator of a relatively large volume connected through a check valve to a pump arranged to draw water from the storage tank; and a cold water delivery pipe system leading from the accumulator to the cold water taps of the dwelling; in which water supply arrangement the diameter of at least the majority of pipes in the cold water delivery pipe system is greater than the diameter of the cold water inlet pipe leading to the accumulator. In this alternative form of the invention, the pump should be arranged to operate whenever the pressure in the accumulator fails below a pre-set value, so as to re-charge the accumulator with water drawn from the storage tank. Consequently, the volume of the storage tank should be at least as great as the volume of the accumulator.

It will be appreciated that the present invention employs a relatively large volume accumulator, which typically has a volume of at least 100 litres, but preferably 200 to 250 litres, and which is pre charged with water for delivery from the taps of a dwelling within which Ref. 1 1642sp the system is installed. The volume of the accumulator is thus at least as great as the largest volume of water which may be expected to be drawn at any one time within a domestic environment, for example, in the running of a bath. In addition, by providing a water delivery pipe system with pipes of a sufficiently large diameter - and thus typically 22 mm pipes the opening of any one tap will not significantly affect the discharge of water from any other tap.

The water supply arrangement of this invention may be modified to include a hot water delivery system. In this case, a hot tank may be provided, within which water is heated for delivery through a hot water delivery pipe system to the hot taps of the dwelling, the hot tank being connected to the cold water delivery pipe system by a pipe of greater diameter than that of the cold water inlet pipe. As with the cold water system, the diameter of at least the majority of pipes in the hot water delivery pipe system should be of substantially the same diameter as the majority of pipes in the cold water delivery pipe system.

Many domestic taps used on basins are intended for the connection thereto of 15 mm pipes. When installing a water supply arrangement of this invention, larger diameter pipes may be run to the taps with a reducer provided in the immediate vicinity of the taps. In the alternative, a 15 mm pipes may be used to connect the tap to a distribution pipe of a larger diameter, smaller diameter pipes being used only for runs direct to taps and not having any branching therefrom.

Ref. 1 1642sp By way of example only, two specific embodiments of water supply arrangements of this invention will now be described in detail, reference being made to the accompanying drawings, in which:

Figure 1 diagrammatically illustrates the first embodiment; and Figure 2 diagrammatically illustrates the second embodiment.

Referring initially to Figure 1, there is shown an incoming cold water supply pipe 10 connected to an underground water main (not shown) through a stopcock 11. This supply pipe 10 usually is a 15 mm copper pipe, though older dwellings may have supply pipes of other sizes or materials. The supply pipe is connected to a T-piece 12 through an automatic unidirectional valve 13, the T-piece having two 22 mm pipes 14 and 15, connected thereto.

Pipe 14 connects through a gate valve 16 to an accumulator 17 having a water capacity of about 200 litres. This accumulator comprises a steel vessel within which is supported an elastically extendible bladder 18, pipe 14 communicating through the wall of the accumulator to the bladder. The vessel is sealed in an airtight manner, such that on expansion of the bladder by driving water under pressure into the bladder, air surrounding the bladder is compressed.

Pipe 15 delivers cold water to various taps 19 within the dwelling, branch pipes also of 22 mm diameter being branched off pipe 15 as appropriate, using T-pieces 20. Pipe 15 also delivers water to an automatic pressure-relieving valve 21 associated with a mains water pressure hot tank 22. An expansion chamber 23 is connected to the valve 21, as is a pressure- relief pipe 24, leading to a tundish 25. The outlet pipe 26 from the valve 21 Ref11642sp supplies water under mains pressure to the interior of the hot tank 22. In the event that pressure within the hot tank rises above a pre- determined value set by valve 21, water is permitted to be discharged from the hot tank through pipe 27, normally closed by valve 21, but opened so that water may be delivered to the tundish 25 and thence to a drainpipe 28. Normal expansion of water within the tank 22 consequent upon heating of that water by the indirect heating coil 29 is accommodated by the expansion chamber 23.

The hot tank 22 has an outlet pipe 30 which is connected through a further gate valve 31 to hot taps 32 distributed around the building, and usually closely disposed to the cold water taps 19. The hot water supply pipes are all of 22 mm diameter and are arranged in a generally similar manner to that described above for the cold water pipes.

In use, the entire hot and cold water delivery system is pressurised to the maximum pressure of the mains water supply, that pressure being maintained by the uni-directional valve 13. The accumulator is automatically charged with water such that the pressure within the accumulator is also that of the mains water supply, and typically the accumulator then holds between 200 and 250 litres, depending upon that pressure. As all of the plumbing downstream of the accumulator to the taps is of 22 mm diameter, the flow rate achievable through those pipes at the pressures concerned is greater than the flow rate which ordinarily is required through any tap on the system. Thus, if a hot or cold water tap is already delivering water, the opening of a further hot tap or cold tap will not significantly affect the delivery through the already open tap, and full normal flow rates may be expected from both taps.

Ref.1IfA2sp Figure 2 shows an alternative arrangement where the pressure of the incoming cold water supply is insufficient to permit charging of the accumulator to the required extent for that accumulator to hold as much water as may normally be expected to be delivered at any one time through a tap.

Thus, the arrangement of Figure 2 may be employed when the incoming cold water supply is at a pressure of less than about 0.7 bar for the majority of the time.

In Figure 2, like parts with those of Figure 1 are given like reference numbers, and will not be described again here. Only those features of 10 difference will be discussed, below.

The incoming cold water supply pipe 10 is connected to a float valve assembly 35 fitted to a cold water tank 36. The assembly 35 has a bail float 37 which opens the valve assembly 35 when the water level in the tank falls below a pre-determined level, and closes the valve assembly when the tank 15 is re-filled from the cold water supply to another predetermined level.

A pump 38 draws cold water from the tank 36 through a 22 mm pipe 39, and delivers that water under pressure through uni-directional valve 30 to Tpiece 12. Thus, the pressure downstream of the uni-directional valve is at least as high as the expected mains water pressure of the arrangement 20 shown in Figure 1.

A pressure sensing switch (not shown) is either provided on the downstream side of the pump or in the system downstream of uni- directional valve 13, to control operation of the pump 38. When the pressure falls below Ref. 1 1642sp a pre-set value, the pump is operated to draw water from tank 36 and maintain charging of the accumulator 17.

In all other respects, the arrangement of Figure 2 operates in the same manner as that of Figure 1 and will not be described again here.

Ref.11642SP

Claims

1 A water supply arrangement for a domestic dwelling, comprising: a cold water inlet pipe for cold water drawn from a mains supply; an accumulator of a relatively large volume connected through a check valve to the inlet supply pipe; and a cold water delivery pipe system leading from the accumulator to the cold water taps of the dwelling; in which water supply arrangement the diameter of at least the majority of pipes in the cold water delivery pipe system is greater than the diameter of the cold water inlet pipe leading to the accumulator.

2. A water supply arrangement for a domestic dwelling, comprising: a cold water inlet pipe for cold water drawn from a mains supply and supplying cold water to a storage tank; an accumulator of a relatively large volume connected through a check valve to a pump arranged to draw water from the storage tank; and a cold water delivery pipe system leading from the accumulator to the cold water taps of the dwelling; in which water supply arrangement the diameter of at least the majority of pipes in the cold water delivery pipe system is greater than the diameter of the cold water inlet pipe leading to the accumulator.

3. A water supply arrangement as claimed in claim 2, wherein the 20 pump is arranged to be operated whenever the pressure in the accumulator fails below a pre-set value, so as to re-charge the accumulator with water drawn from the storage tank.

Ref.11642sp

4. A water supply arrangement as claimed in claim 3, wherein the volume of the storage tank is of the same order as the volume of the accumulator.

5. A water supply arrangement as claimed in any of claims 2 to 4, 5 wherein the volume of water stored in the storage tank is maintained by means of a float valve assembly fitted to cold water supply pipe.

6. A water supply system for a domestic dwelling, comprising: a cold water inlet pipe for cold water drawn from a mains supply; an accumulator connected through a check valve to the inlet supply pipe; and a cold water delivery pipe system leading from the accumulator to the cold water taps of the dwelling; in which water supply arrangement the accumulator is of a sufficiently large volume to accommodate the largest volume of water normally expected to be drawn from the system at any one time, and the diameter of at least the majority of pipes in the cold water delivery pipe system is greater than that normally employed for a domestic cold water system.

7. A water supply arrangement as claimed in any of the preceding claims, wherein there is a hot tank in which water is heated for delivery through a hot water delivery pipe supply system to the hot water taps of the dwelling, the hot tank being connected to the cold water delivery pipe system by a pipe of a greater diameter than that of the cold water inlet pipe and the diameter of at least the majority of pipes in the hot Ref.116425P water delivery pipe system being of substantially the same diameter as a majority of the pipes in the cold water delivery pipe system.

8. A water supply arrangement as claimed in claim 7, wherein the greater diameter pipes of the cold water delivery pipe system are 5 connected substantially directly to the cold water taps.

9. A water supply arrangement as claimed in claim 8, wherein the greater diameter pipes of the hot water delivery pipe system are connected substantially directly to the hot water taps.

10. A water supply arrangement as claimed in any of the preceding 10 claims, wherein the accumulator is able to hold at least 20 litres of water.

11. A water supply arrangement as claimed in claim 9, wherein the accumulator is able to hold at least 100 litres of water.

12. A water supply arrangement as claimed in claim 11, wherein the accumulator is able to hold a maximum volume of 250 litres of water.

13. A water supply arrangement as claimed in any of the preceding claims, wherein the cold water inlet pipe is of 15mrn diameter and the cold water delivery pipe system utilises 22mrn diameter pipes.

14. A water supply arrangement as claimed in any of the preceding 20 claims and substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.