WO1998048120A1

WO1998048120A1 - Water treatment and delivery apparatus

Info

Publication number: WO1998048120A1
Application number: PCT/GB1998/001132
Authority: WO
Inventors: David Mcalistair Walker
Original assignee: David Mcalistair Walker
Priority date: 1997-04-19
Filing date: 1998-04-20
Publication date: 1998-10-29
Also published as: GB9924719D0; GB2339611B; GB2339611A; AU7063798A

Abstract

A water treatment and delivery apparatus comprising a tap or faucet (4) for controlling the supply of water at mains pressure to a delivery spout (6) and between the tap or faucet (4) and an outlet nozzle (18) of the delivery spout (14) a replaceable cartridge (21) containing packing material for filtering and/or deionizing and/or chemically treating water passing to the outlet nozzle (18). To change the water treatment material when its activity is exhausted requires simple removal of the old cartridge (21) and replacement with a new cartridge (21) containing fresh treatment material. The invention also provides an installation for providing filtered and deionized water to a location above a sink, comprising an under-sink filter unit (2) for filtering water from a mains supply and delivering the filtered water to a dispensing tap or faucet (4) and a delivery spout (6) for delivering the filtered water from the tap or faucet (4) to the location above the sink, in which between the tap or faucet (4) and an outlet nozzle (18) of the delivery spout (6) there is a replaceable cartridge (21) containing packing material for dionizing and/or chemically treating the filtered water passing from the tap or faucet (4) to the outlet nozzle (18).

Description

TITLE

Water treatment and delivery apparatus

DESCRIPTION

Field of the Invention

The invention relates to apparatus for treating and delivering water from a tap or faucet. Throughout this specification the word "tap" or "faucet" is used to denote any valve for controlling the flow of water through a delivery pipe.

Background Art

Water filters are known for use in domestic environments for providing a supply of filtered mains water through a tap or faucet that is generally provided immediately adjacent a kitchen sink. A conventional supply apparatus for such a filtered water supply would be a narrow bore swan-neck delivery pipe of internal diameter 1.0 cm or less, leading from a lever-actuated tap or faucet. The swan-neck delivery pipe would normally have one or two rubber O-ring seals at its lower end to enable it to seal with the tap or faucet while still permitting angular rotation. The entire installation would comprise a filter chamber at mains pressure beneath the kitchen sink, a mains water supply to the filter chamber and a connection between the filter chamber and the tap or faucet to pass filtered water through the swan-neck delivery pipe when the lever of the tap or faucet is actuated.

The filter chamber typically would contain a granular activated carbon filter medium which would remove from the mains water all sediment, particles and water-borne organisms. Filtration is real-time, meaning that the water flows directly from the mains supply through the filter to the tap or faucet and swan-neck delivery pipe when the tap or faucet lever is depressed. There is no intervening reservoir between the filter and the tap or faucet for the storage of a quantity of filtered water for supply when needed.

The above domestic water filtration and supply apparatus delivers good quality drinking water which is cleaner than unfiltered water. The supply is slower than that through a tap or faucet delivering unfiltered water at mains pressure, because a pressure gradient is established through the filter medium and that slows down the flow. The apparatus is used mainly to fill drinking glasses, jugs, kettles and cooking pans; so generally volumes of no more than one litre at a time are dispensed. The relatively slow delivery rate is therefore not a problem. However, it is a problem that the active carbon filter is ineffective in removing soluble ionic compounds from the water. A hard water supply, with a high content of dissolved calcium salts, cannot be converted to a soft water supply by passing it through an activated carbon filter.

It is known that hard water can be converted to soft water by removal of dissolved alkaline earth metal salts using an ion exchange resin. The resin removes the alkaline earth metal ions such as calcium ions Ca⁺⁺ and replaces them with sodium ions Na+ . Such ion exchange resins are used in commercial water purification systems and provide good soft deionized water. The lifetime of an ion exchange resin, before it has to be recharged or replaced, is however considerably less than that of an active carbon filter. In an under-sink carbon filtration unit, the filter packing would be designed to be changed once every six months, once every year or once everythree years according to the model and design of filtration unit. An ion exchange resin would need replacement every month. For that reason, no filtration unit has yet been offered for commercial sale with both a carbon filter and an ion exchange resin in the same unit. All attempts to design such a unit have followed either the design logic of attempting to extend substantially the lifetime of the ion exchange unit or attempting to provide in the under-sink filter a readily accessible and readily replaceable cartridge of ion exchange resin which can be replaced without spilling water from the filter unit, without disturbing the more permanent carbon filter and without requiring plumber's tools to open and close the filter unit housing.

There is also a need to provide other types of efficient treatment of water from a mains supply. In different circumstances the water may require disinfection to kill organims or chemical treatment to remove contaminants such as lead or nitrates .

The Invention

The invention provides a water treatment and delivery apparatus comprising a tap or faucet for controlling the supply of water at mains pressure to a delivery spout, and between the tap or faucet and an outlet nozzle of the delivery spout a replaceable cartridge containing packing material for filtering and/or deionizing and/or chemically treating water passing to the outlet nozzle.

The invention is based on a realization of the advantages of containing the packing material in a replaceable cartridge and of positioning the replaceable cartridge downstream of the tap or faucet. In conventional under-sink water filtration installations steps have to be taken to isolate the filter chamber from mains water pressure before opening that chamber to replace the filter material. This invention utilizes the supply tap or faucet itself as the isolating means, and provides the replaceable cartridge in an over-sink location between the tap or faucet and the outlet nozzle of the delivery spout. In a first aspect of the invention the replaceable cartridge may be the entire delivery spout which may be formed as a removable swan-neck delivery spout. In that case the invention provides a removable swan-neck delivery spout for a domestic mains-pressure water supply, comprising at one end a delivery nozzle and at the other end a swivel coupling incorporating at least one O-ring seal for coupling the delivery spout to a valve block of a tap or faucet in a manner that enables the spout to swivel from side to side in normal use and to be easily removable for replacement ; and encapsulated in the spout a packing material for filtering, disinfecting or chemically treating water as it is delivered from the tap or faucet.

By encapsulating the water treating material into a readily replaceable swan-neck delivery spout, the invention provides an effective solution to the aforementioned problems. To change the treatment material when its activity is exhausted requires simple removal of the old delivery spout and replacement with a new delivery spout containing fresh treatment material. The old delivery spout can be disposed of or recycled. Because the swan-neck delivery spout is a self-contained unit, there is little risk of contaminating its contents during replacement and the invention accordingly allows improved hygiene .

The delivery spout according to this first aspect of the invention may be a simple push fit into the tap, where it is sealed by the one or more 0-rings carried by the swivel coupling of the spout. Sealing contact is made with a cylindrical inner surface of an outlet bore of the valve block of the tap or faucet, so that the delivery spout can swivel about its vertical axis without affecting the seal. If desired, a screw-thread at the end of the delivery spout can engage with a cooperating thread in the outlet bore of the valve block, to retain the spout in position. The O-ring seal or seals are still utilized for sealing, but the removal of the delivery spout then requires a preliminary turn or turns to disengage the screw threads before it can be lifted out of the valve block. The delivery spout unit may be made from metal or plastic.

In a second aspect of the invention the replaceable cartridge may be replaced without replacing the entire spout. For example the cartridge may be a replaceable element in the delivery spout itself, so that for replacement of the packing material the delivery spout is removed and opened up, and a new cartridge inserted. In such an embodiment the delivery spout, which may be a swan-neck spout, has at one end its outlet nozzle and at the other end a swivel coupling incorporating at least one O-ring seal for coupling the delivery spout to a valve block of a tap or faucet in a manner that enables the spout to swivel from side to side in normal use and to be easily removable for replacement.

By packing the water treating material as a readily replaceable cartridge in an easily removable swan-neck delivery spout, the invention provides an effective solution to the aforementioned problems. To change the treatment material when its activity is exhausted requires simple removal of the old cartridge and replacement with a new cartridge containing fresh treatment material . Because the cartridge is a self-contained unit, there is little risk of contaminating its contents during replacement and the invention accordingly allows improved hygiene .

In another equally preferred embodiment of the invention the replaceable cartridge can be housed in a valve block for the tap or faucet, so that water delivered through the tap or faucet passes through the packing material before reaching the delivery spout. Either the valve block may be a single faucet valve block for controlling only the on/off supply of water through the packing material and delivery spout, or the valve block may be a composite valve block incorporating taps or faucets for the independent supply of domestic hot water and untreated cold water to a sink-top delivery spout and a separate tap or faucet for the supply of a separate drinking water delivery spout.

In a further embodiment of this second aspect of the invention the replaceable filter cartridge can be housed in an above-sink stand-alone housing communicating with the tap or faucet and with the delivery spout .

In a third aspect of the invention the delivery spout may comprise separate passages for hot and cold water-, both supplies being dispensed from the same output nozzle. In such a case the apparatus comprises a composite valve block incorporating taps or faucets for the independent supply of domestic hot water, domestic cold water and treated drinking water preferably to a single delivery spout. If desired, only two water supplies are provided to the valve block: a domestic hot water supply and a domestic cold water supply, and the tap or faucet for supplying treated drinking water to the delivery spout delivers water from the domestic cold water supply to the chamber containing packing material for filtering and/or deionizing and/or chemically treating the water as it passes to an output nozzle of the delivery spout. Alternatively three water supplies may be provided to the valve block: a domestic hot water supply; a domestic cold water supply and a supply of filtered cold water from an under-sink filter. The packing material in this alternative would then be an ion-exchangeresin, so that the tap or faucet for supplying treated drinking water to the delivery spout delivers filtered and deionized water. As discussed generally above, the packing material may in this third aspect of the invention be encapsulated in a chamber of the delivery spout itself so that when the packing material is exhausted it may be replaced by the expedient of removing and discarding the spout and replacing it with a new spout packed with fresh material. Preferably, however, the packing material is in a replaceable cartridge so that to replace spent packing material all that is necessary is to open the chamber, remove the cartridge, insert a new cartridge and re-close the chamber. That can be accomplished very simply and efficiently according to the invention by using the tap or faucet which controls the supply of treated drinking water to the delivery spout as the isolating means for isolating the opened chamber from the domestic mains water supply. The cartridge may be the entire delivery spout or it may be a separate readily replaceable cartridge in the spout or in the valve block for the tap or faucet, so that water delivered through the tap or faucet passes through the packing material before reaching the delivery spout. Alternatively the replaceable filter cartridge could be housed in an above-sink stand-alone housing cmmunicating with the tap or faucet and with the delivery spout.

In this third aspect of the invention the delivery spout preferably incorporates passages for allowing untreated hot and/or cold water to be delivered from the same delivery nozzle. With such a delivery spout the valve block has three taps, faucets or other valves: the first for controlling the supply of domestic hot water through a first water passage in the spout, the second for controlling the supply of domestic cold water through the same or a different water passage in the spout; and the third for controlling the supply of water through the packing material and through a preferably separate water passage in the spout to the delivery nozzle. The third such valve is used whenever filtered or softened drinking water is required from the delivery spout .

In all three above aspects of the invention the packing material of the cartridge is preferably an ion exchange resin for softening hard water. Other alternatives are a filter material such as granular activated carbon; a source of chlorine for disinfection of the water, which may be accompanied by a filter material downstream to remove chlorine from the disinfected water; or materials for removing chemical contaminants such as lead or nitrates from the water.

Bacterial filters are available which are capable of removing bacteria from a water supply by filtration. One such range of filters takes the form of ceramic disc filters. Preferably the packing material of the cartridge includes one such filter before or after the packing materials discussed above. If the ceramic disc filter is positioned downstream of other filter material such as active carbon then it requires cleaning less frequently than if it were positioned upstream, but the upstream location has the advantage that the bacteria are removed from the water supply before the packing material, so that the packing material does not become a breeding ground for bacterial growth. Any bacterial filter incorporated into the cartridge will however require regular removal and cleaning since the small pore size encourages clogging.

The cartridge for use with apparatus according to the invention may be used with sources of cold, hot or boiling mains-pressure water, provided that a packing material effective at the appropriate temperature is used. For maximum effectiveness, most packing materials will require a certain contact time with the water flowing through them. Accordingly the invention may provide means, such as a constriction in the water flow path, for limiting the flow of water through the spout to a rate at which the filtering, disinfecting or chemical treatment effect of the packing material is most efficient.

If the packing material in the cartridge is an ion exchange resin, the apparatus of the invention may be used in conjunction with an under-sink filter in an installation for dispensing a supply of filtered and deionized water. In such an installation, the filter medium in the under-sink filter is preferably activated charcoal. The filter medium is preferably packed in a replaceable cartridge container, which according to size requires replacement every six months, one year or three years. In contrast, the replaceable cartridge containing the ion exchange resin of the unit of the invention requires replacement every month, but that is no problem because the replacement operation is so quick and easy, involving simply pulling out and discarding one resin-packed cartridge and pushing a new one into place while the tap or faucet is turned off. No under-sink work is involved, and replacement is just as simple asthe regular washing down and cleaning of a sink surround.

Drawings

Figure 1 is a schematic section through an installation comprising an under-sink filtration unit and a water treatment and delivery apparatus according to the invention;

Figures 2 and 3 are sections through two alternative swan-neck delivery spouts for use in a water treatment and delivery apparatus according to a first aspect of the invention;

Figure 4 is a section through a water treatment and delivery apparatus according to the first aspect of the invention, comprising a swan-neck delivery spout mounted in a valve block of a tap or faucet ; Figure 5 is a partial axial section through a water treatment and delivery apparatus according to a second aspect of the invention;

Figure 6 is a partial axial section through another embodiment of a water treatment and delivery apparatus according to the second aspect of the invention;

Figure 7 is a front view of a water treatment and delivery apparatus according to a third4Xaspect of the invention;

Figure 8 is a side view, partly in section, of the apparatus of Figure 7 ;

Figure 9 is a side view, partly in section, of a further water treatment and delivery apparatus according to the third aspect of the invention;

Figure 10 is a section taken along the line X-X of Figure 9.

In Figure 1, a filtration unit 1 comprises an under-sink filter 2 receiving water at mains pressure from a supply 3 and delivering it directly to a tap 4. A dispensing lever 5 on the tap or faucet 4 dispenses the filtered water through a swan-neck delivery spout 6. The spout 6 has a portion 7 of enlarged diameter containing a packing of an ion exchange resin which deionizes the filtered water as it is dispensed.

Conventional swan-neck delivery spouts for under-sink filters have an internal diameter of 1.0 cm or less. The diameter of a spout containing ion-exchange resin for use in a unit according to the invention may be increased to fromp579X--cτι5 to 2.5 cm, depending on the porosity of the ion exchange resin which it contains, so that the presence of the resin does not reduce the rate flow of water.

The filter 2 has an active carbon filter element or cartridge which requires replacement at intervals of 6 months, 12 months or 3 years. In contrast, the ion exchange resin requires replacement more frequently, for example monthly, but by packing the resin in the easily accessible and easily replaceable pipe 6, changing the pipe and resin is an extremely simple task.

Figure 2 shows a swan-neck delivery spout 6 in which the resin extends substantially the length of the spout. Figure 2 shows the sealing and anchorage means for retaining the spout in an outlet bore of the tap or faucet 4, comprising two recessed 0-rings 8.

Figure 3 shows a modified sealing and anchorage means in which only one O-ring 8 is provided, but associated with a screw-thread 9 for anchoring the spout 6 to the tap or faucet 4. In practice the delivery spout 6 is not screwed down to the limit f the screw thread 9. It is screwed down part-way only so that it is freely rotatable through 360° over the sink or basin alongside which it is installed.

Figure 4 illustrates an alternative swan-neck delivery spout 6 inserted in a valve block 10 of a domestic kitchen tap unit. The delivery spout 6 incorporates a packed conduit 11 and a by-pass conduit 12. Three O-ring seals 13a, 13b and 13c are provided around a swivel coupling portion 14 of the delivery spout 6. Between the O-ring seals 13a and 13b is a first supply chamber 15 and between the O-ring seals 13b and 13c is a second supply chamber 16. A hot tap 17 controls the supply of domestic hot water to the first supply chamber 15 from whence it is delivered through the by-pass conduit 12 to a delivery nozzle 18. A cold tap 19 controls the supply of cold domestic unfiltered mains water to the first supply chamber 15 from whence it also is deliered through the same or a separate by-pass conduit 12 to the delivery nozzle 18. Hot and cold supplies may be delivered together by turning on both taps 17 and 19. A faucet lever 20 controls the supply of the same cold domestic unfiltered mains water to the second supply chamber 16 from whence it passes through the packed conduit 11 to the delivery nozzle 18. If the packing in the conduit 11 is a filter medium such as active carbon, then the nozzle 18 dispenses filtered water. If the packing is an ion exchange resin then the nozzle 18 dispenses softened, deionized water. In both cases, however, the water supply to the valve block is simply the usual domestic hot and cold water supplies.

Figure 4 also shows a preferred shape for the delivery spout 6, with an enlarged inle end 21. That shape provides an attractively slim outlet end of the swan-neck, while providing more volume near the intake end for a greater volume of ion-exchange resin or filter medium as packing. Preferably baffles 22 are moulded into the spout 6 at the enlarged inlet end 21 within the conduit 11, for inducing turbulence in the water passing through the conduit 11, decreasing the total flow rate and increasing its duration of contact with the packing. A restricted orifice flow restrictor 23 as shown or a bacterial filter may also optionally be incorporated into the delivery spout 6 at the swivel coupling end.

The delivery spout of Figure 4 may be injection moulded in two pieces as two half-shells which are then joined together by adhesive or heat- or ultrasonic-welding.

Figure 5 illustrates a water treatment and delivery apparatus according to a second aspect of the invention in which a valve block 10 has an associated on-off valve (illustrated schematically as 111) for controlling the flow of water at mains pressure through the valve block from an inlet pipe 112 to a delivery spout 114 which terminates in an outlet nozzle 115. The on/off valve is controlled by a mechanism 116 which as illustrated is a spring actuated lever. The on-off valve 111 is shown simply as a valve member seated on an annular valve seating to interrupt the water flow from the inlet pipe 112 towards the delivery spout 14. No mechanism is shown for unseating the valve 11 to permit water flow, but it will be understood that a range of such mechanisms is available and any may be chosen in accordance with the invention. Equally the actuating lever 116 may be replaced by a rotary tap.

The delivery spout 114 is easily removable from the valve block 10, in which it is received as a simple push fit with the necessary water seal being established by two O-ring seals 118.

The construction thus far described is generically the same as that described above for Figures 1 to , in which the delivery spout 6 is permanently filled with packing material 11 which may be a filter medium, an ion exchange resin, an impregnated packing for chemically treating the water passing through the delivery spout, or a packing with two or more of the above functions so that the filled spout itself is the packed cartridge. In this second aspect of the present invention, however, the packing material is inserted into the delivery spout 114 in the form of a removable cartridge 120 which can be removed in its entirety and replaced. To remove the cartridge, the delivery spout 114 can be lifted out of the valve block 10, opened by unscrewing a bottom cap 122 to expose a cartridge chamber, and the cartridge 120 may then be exchanged. Instead of the screw fitting to connect together the delivery nozzle 14 and its end cap 122 as illustrated, any other quick release and watertight fastening might be adopted, such as a bayonet fixing. The apparatus of Figure 5 has all of the advantages of that disclosed above in connection with the embodiment of Figures 1 to 4, plus the additional advantage that when it becomes time to change the filter cartridge, only a relatively inexpensive cartridge need be exchanged, and not the entire delivery spout .

Figure 6 illustrates another embodiment according to this second aspect of the invention, in which many of the parts are essentially the same as those illustrated in Figure 5. Parts with the same function have been given the same reference numerals as in Figure 5. The principal difference between Figures 5 and 6 is that in Figure 6 the cap 122 which retains the cartridge 120 in position is located at the top of a fixed pedestal portion 114' of the delivery spout. To change the cartridge 120, the end cap 122 is removed, the cartridge lifted out and a new one inserted, and the cap 122 is then replaced. There is no need to take the entire spout 114 out of its valve block 10.

Because the portion 114' of the delivery spout which is connected to the valve block 10 is immovable, the delivery nozzle end 114 ' ' of the spout 114 extends from a rotary bushing 124 which is rotatable with respect to the fixed portion 114' and the end cap 122 of the delivery spout 114.

In both of the illustrated embodiments of Figures 5 and 6, the cartridge 120 is readily replaceable, and can be replaced without having to replace the entire spout. If the cartridge 120 contains ion exchange resin, then it should be replaced every two to four weeks. This is in contrast with carbon filters, which have up until now been provided in under-sink installations and which require changing only every one , two or even three years . The apparatus of the invention may be used in conjunction with such an under-sink filter in a general arrangement such as that illustrated in Figure 1, in which case the cartridge 120 would contain only ion exchange resin and would require changing every two to four weeks. Alternatively the water supply to the apparatus of the invention could be completely untreated domestic mains water, in which case it would be desirable for the cartridge 120 to contain both a filter medium and an ion exchange resin or other chemical treatment means . In that case the carbon filter medium would be replaced rather more frequently than is strictly necessary, but the cartridge 120 would still need to be replaced every two to four weeks to renew the exhausted ion exchange resin.

Referring next to Figures 7 and 8, the apparatus of a third aspect of the invention comprises a valve block 230 which is provided with hot and cold taps 232 and 234 for controlling the delivery of untreated water at mains pressure through a delivery spout 236. Depending on local water authority requirements, it may be necessary to divide the delivery spout 236 into separate passages, one for the hot water supply and one for the cold water supply, so that the two water supplies mix together only at the outlet nozzle 238.

In the valve block 230 there is a third valve 240 controlled by an operating lever 242 for controlling the supply of cold water at mains pressure through a water treatment cartridge 244 to the delivery spout 236. In the delivery spout 236, the water delivered by the lever 242 through the treatment cartridge 244 may pass through the same cold water passage in the spout 236 as the untreated water controlled by the tap 234; or it may have its own dedicated water passage.

Figure 7 illustrates schematicaly one possible form of quick release access to the cartridge 244 for ease of replacement. A lid portion 246 of a cartridge-receiving chamber 248 is hinged at 250 and is provided with two snap-over latches 252. To change the cartridge, it is simply necessary to unfasten the latches 252, raise the lid 246, lift out the old cartridge 244 and drop in a new one. A rubber seal 254 around the edge of the cartridge container 248 ensures that there is no water leakage in use.

The cartridge is readily replaceable, and in this embodiment can be replaced without having to replace the entire spout. If the cartridge contains ion exchange resin, then it should be replaced every two to four weeks. This is in contrast with carbon filters, which have up until now been provided in under-sink installations and which require changing only every one, two or even three years . The water supply to the apparatus of the invention may be completely untreated domestic mains water, in which case it is desirable for the cartridge 244 to contain both a filter medium and an ion exchange resin or other chemical treatment means. In that case the carbon filter medium would be replaced rather more frequently than is strictly necessary, but the cartridge would still need to be replaced every two to four weeks to renew the exhausted ion exchange resin.

Figures 9 and 10 illustrate a further embodiment of this third aspect of the invention, and use the same reference numerals as those used in Figures 7 and 8 for the same or analogous parts. In Figure 3 the taps 232 and 234 and drinking water lever 242 are not shown, but it will be understood that the same hot and cold water controls will be provided in the valve block 230. Depression of the lever 242 establishes a supply of mains cold water to the cartridge 244 in the direction of the arrow A, to cause water to flow the packing material in the cartridge 244 to the top of the chamber 248. From there it passes down a conduit 260 moulded in a side wall of the chamber 248 to a bore 262 in the valve block 230 which communicates with a passage 264 for treated water in the spout 236. Figure 10 illustrates the internal partitioning of the spout 236 which defines separate passages 264, 266 and 268 for, respectively, treated drinking water, untreated cold water and untreated hot water.

Changing the filter cartridge of Figure 9 is simple. With the lever 242 not depressed, the water supply to the chamber 248 is cut off. A cap 270 is unscrewed, and the old filter cartridge 244 is lifted out and replaced by a new one. The cap 270 is then replaced, with a water seal being established by the O-ring seal 254.

In both the embodiment of Figures 7 and 8 and that of Figures 9 and 10, the apparatus can supply, from the same nozzle, domestic hot water, domestic cold water or treated drinking water. The water supply to the apparatus is, however, simply a domestic hot and cold water supply. No under-sink filter is needed, and neither is there any separate spout for the drinking water delivery. The filter in both illustrated embodiments is in the form of a replaceable cartridge to give maximum ease of replacement above-sink, and maximum economy.

Claims

1. A water treatment and delivery apparatus comprising a tap or faucet (4) for controlling the supply of water at mains pressure to a delivery spout (6) , characterized in that between the tap or faucet (4) and an outlet nozzle (18) of the delivery spout (6) there is a replaceable cartridge (21) containing packing material (11) for filtering and/or deionizing and/or chemically treating water passing to the outlet nozzle (18) .

2. Apparatus according to claim 1, wherein the replaceable cartridge comprises a swan-neck delivery spout (6) for a domestic mains-pressure water supply, comprising at one end the delivery nozzle (18) and at the other end a swivel coupling (14) incorporating at least one O-ring seal (13) for coupling the delivery spout (6) to a valve block (10) of the tap or faucet (4) in a manner that enables the spout (6) to swivel from side to side in normal use, characterized in that the spout (6) is easily removable for replacement; and in the spout (6) is encapsulated the packing material (11) for filtering, disinfecting or chemically treating water as it is delivered from the tap or faucet (4) .

3. Apparatus according to claim 1, wherein the cartridge (21) is received within the delivery spout (114) and is readily removable therefrom for renewal of the packing material .

4. Apparatus according to claim 1, wherein the cartridge (21) is in a valve block (10) for the tap or faucet (4) .

5. Apparatus according to claim 4, wherein the valve block (10) is a single faucet valve block for controlling only the on/off supply of water through the packing material (11) and delivery spout (6) .

6. Apparatus according to claim 4, wherein the valve block (10) is a composite valve block incorporating taps or faucets for the independent supply of domestic hot water and untreated cold water to a sink-top delivery spout and a separate tap or faucet (20) for the supply of filtered and treated cold water to the same or to a separate drinking water delivery spout .

7. Apparatus according to claim 6, wherein only two water supplies are provided to the valve block (10) : a domestic hot water supply and a domestic cold water supply; and the tap or faucet (20) for supplying treated drinking water to the delivery spout (6) delivers water from the domestic cold water supply to the cartridge containing the packing material for filtering and/or deionizing and/or chemically treating the water as it passes to the output nozzle (18) of the delivery spout

(6) .

8. Apparatus according to claim 6, wherein three water supplies are provided to the valve block (10) : a domestic hot water supply, a domestic cold water supply, and a supply of filtered cold water from an under-sink filter; and the tap or faucet (20) for supplying treated drinking water to the delivery spout (6) delivers water from the supply of filtered cold water to the cartridge which contains an ion exchange resin as the packing material (11) , for deionizing the water as it passes to the output nozzle (18) of the delivery spout (6) as filtered and deionized water.

9. Apparatus according to any of claims 1 to 7 , wherein the packing material (11) is an ion exchange resin.

10. Apparatus according to any of claims 1 to 7 , wherein the packing material (11) comprises a filter material and an ion exchange resin.

11. Apparatus according to claim 10, wherein the filter material in the packing material (11) is active carbon.

12. Apparatuss according to any preceding claim, wherein the cartridge (21) also contains a bacterial filter for removing bacteria from the water as it passes to the output nozzle (18) .