More particularly, the invention relates to water meter fixtures which can be coupled to or incorporated in a water meter in order to improve the security thereof and render the water meter less susceptible to unauthorised tampering. The invention also provides novel forms of valves and anti-backflow valves.

According to one aspect of the invention there is provided a cutoff valve assembly for coupling between a water meter and a water supply line, characterised in that the assembly includes a valve body and a valve cartridge which is slidably insertable in the body.

Preferably, the body includes an auxiliary outlet port which can be opened in order to allow water to issue therefrom whereby when the auxiliary port is open, the pressure of water is low enough within the valve body to enable withdrawal and replacement of the cartridge.

In accordance with another aspect of the invention there is provided a check valve assembly including a main body portion and a check valve cartridge slidably mounted in a bore in said main body portion, said cartridge including a generally cylindrical body portion and a mounting portion which is rotatably coupled to said cylindrical body portion, the arrangement being such that the mounting portion can be threaded into said bore without causing rotation of the cylindrical body portion relative to the main body portion.

The invention also provides a method of changing the cartridge in a valve assembly as defined above including the steps of moving the valve element to its open position,

removing said plug, removing said spindle, unscrewing the mounting portion from said threads and sliding said cartridge from said valve body.

The invention also provides apparatus for tamperproofing a fitting having at least one threaded spigot, said apparatus including: a body having mounting lugs projecting therefrom; a nut for mounting on the threads of the outlet spigot; at least one nut cover bracket; and security fastening means for connecting the nut cover bracket to said mounting lugs such that the nut cover bracket at least partly covers said nut whereby unauthorised removal of the nut from said threads is prevented.

The invention also provides a tail and nut assembly for use with a fitting having at least one threaded spigot, said assembly including a tail and a nut mounted thereon, said tail being in the form of a hollow tubular body having laterally projecting mounting lugs said lugs having threaded holes therein for receipt of security screws.

Preferably the anti-backflow valve includes dual check valves.

The invention will now be further described with reference to the accompanying drawings in which: Figure 1 is a schematic side view of a conventional water meter installation; Figure 2 is a side view of a water meter installation in accordance with the invention; Figure 3 is a plan view of the installation; Figure 4 is a cross-sectional view of the installation partly in section; Figure 5 is a side view of the installation showing security brackets; Figure 6 is a plan view of the installation of Figure 5; Figure 7 is a side view of a modified arrangement in which the housing for the anti- backflow valve is integral with the water meter; Figure 8 is a schematic cross-sectional view through the arrangement of Figure 7; Figure 9 is a side view of a further embodiment in which the housing for the water

meter anti-backflow valve and cutoff valve are integrally formed; Figure 10 is a schematic cross-sectional view through the arrangement shown in Figure 9; Figure 11 is a side view of an anti-tamper bracket; Figure 12 is a plan view of the bracket; Figure 13 is an end view of the bracket; Figure 14 is a cross-sectional view along the line 14-14; Figure 15 is a side view of a broach head screw; Figure 16 is a plan view of the screw; Figure 17 is a front view of the cutoff valve body; Figure 18 is a rear view of the cutoff valve body; Figure 19 is a cross-sectional view through the cutoff valve; Figure 20 is an exploded view of the cutoff valve; Figure 21 is a cross-section through a security bracket; Figure 22 is a cross-section through a modified form of security bracket; Figure 23 is a sectional view through the cutoff valve cartridge assembly; Figure 24 is an exploded view of the cutoff valve cartridge assembly; Figure 25 is a side view of the cutoff valve handle; Figure 26 is a plan view of the cutoff valve handle; Figure 27 is a cross-sectional view along the line 27-27; Figure 28 is a side view of the cutoff valve spindle; Figure 29 is another side view of the cutoff valve spindle; Figure 30 is a plan view of the cutoff valve spindle; Figure 31 is a cross-sectional view along the line 31-31; Figure 32 is a side view of a spindle shoulder; Figure 33 is a plan view of the spindle shoulder; Figure 34 is a cross-sectional view along the line 34-34; Figure 35 is a side view of a restriction plate; Figure 36 is a plan view of the restriction plate; Figure 37 is a cross-sectional view along the line 37-37; Figures 38 to 51 are schematic drawings which show the operation of the cutoff valve

handle; Figure 52 is a longitudinal cross-section through a modified form of cutoff valve which incorporates a filter cartridge; Figure 53 is a cross-sectional view through a further embodiment of the cutoff valve which incorporates a filter cartridge; Figure 54 is a modified form of cutoff valve which incorporates a butterfly valve; Figure 54A is a cross-section through a modified form of cutoff valve; Figure 54B is a plan view of the valve shown in Figure 54A; Figure 54C is a schematic cross-section through the cartridge used in the valve of Figure 54A; Figure 54D is an exploded view of the cartridge; Figure 54E is a schematic view of a valve cartridge using a butterfly valve plate; Figure 54F is an exploded view of the cartridge shown in Figure 54B; Figure 55 is a cross-section through a preferred form of anti-backflow valve; Figure 56 is an exploded view of the valve shown in Figure 55; Figure 57 is a downstream end view of the anti-backflow valve; Figure 58 is an upstream end view of the anti-backflow valve; Figure 59 is a side view of a check valve cartridge which is used in the valve of Figure 55 showing the valve elements in an open position; Figure 60 shows the valve elements in a closed position; Figure 61 is a side view of the check valve cartridge; Figure 62 is a front end view of the cartridge; Figure 63 is a rear end view of the cartridge; Figure 64 is an exploded view of the cartridge; Figure 65 is a cross-sectional view along the line 65-65; Figure 66 is a side view of a test cartridge; Figures 67 and 68 are end views of the cartridge of Figure 66; Figure 69 is a cross-sectional view along the line 69-69; Figure 70 is a side view of a filter cartridge; Figures 71 and 72 are end views of the filter cartridge of Figure 70; Figure 73 is a cross-sectional view along the line 73-73;

Figure 74 is a side view of a filter element; Figure 75 is an end view of a filter element; Figure 76 is a schematic side view of an alternative embodiment which has a dual check valve cartridge oriented in a vertical direction; Figure 77 is a plan view of the arrangement of Figure 76; Figure 78 is a cross-sectional side view of the anti-backflow valve incorporating the cartridge; Figure 79 is a side view of the cartridge; Figure 80 is a plan view of a tail and nut of the invention; and Figure 81 is a schematic longitudinal cross section through the tail and nut of the invention.

Figure 1 is a fragmentary view of a typical water meter installation 2. It includes a water meter 4 having a casing 6. The casing has integrally formed therewith threaded inlet and outlet spigots 8 and 10. The inlet spigot 8 is connected by means of a connecting sleeve 11 having a nut 12. The nut 12 is, in use, threadably mounted on the inlet spigot 8 and threads on the other end of the sleeve 11 are received within a threaded socket at the outlet of an isolating tap or valve 16, the inlet of which is connected to a mains supply line 18 by means of a compression nut 20 or the like.

The outlet spigot 10 is connected by means of an elbow 22 to a service line 24 fitted with a compression nut 26 or the like. One end of the elbow has threads 27 for coupling with the nut 26. The other end of the elbow 22 has a nut 28 which in use threadably receives the outlet spigot 10 of the meter 4.

Whilst this arrangement is quite satisfactory from a functional point of view, it is susceptible to tampering. This can occur by closing of the isolating valve 16 and removing the meter 4 by loosening of the nuts 12,26 and/or 28. Once the meter has been removed, it can be inserted in the reverse direction so that its water metering function operates in the reverse direction so as to decrease the water consumption reading when flow occurs.

Alternatively, a bypass line can be fitted between the valve 16 and the service line 24 to

replace the meter or operate in parallel with the meter.

Figures 2 to 5 illustrate a water meter assembly 30 constructed in accordance with the invention and incorporating a number of improved features, as will be described below.

Similar reference numerals have been used in this drawing and subsequent drawings to denote parts which are the same as or correspond to those of the arrangement shown in Figure 1.

In the water meter assembly 30, the water meter 4 is coupled to a cutoff valve assembly 32 and a check valve assembly 34. The cutoff valve assembly 32 is used to control inlet to the water meter 4 from the mains supply 18. The check valve assembly 34 is provided so as to prevent backflow from the service line 24 in the reverse direction through the meter 4 to the mains supply 18. The provision of a check valve assembly is frequently required by water supply authorities.

Figures 5 and 6 diagrammatically illustrate the use of nut cover brackets 36 and 38 which are used to cover the nuts 12 and 28 respectively in order to prevent unauthorised loosening of the nuts. The brackets 36 and 38 are identical and hence only one of them need be described in detail. Figures 11 to 14 show the structural features of the bracket 36. The bracket 36 includes a semi-cylindrical skirt portion 40, intermediate portion 42 and two mounting lugs 44 and 46. The mounting lugs 44 and 46 include countersunk screw holes 48 and 50 for receipt of security screws 52, one of which is shown in Figures 15 and 16.

As best shown in Figure 3, the cutoff valve assembly 32 includes a body portion 54 having integral, laterally extending mounting lugs 56 and 58, the lugs being provided with screw holes 60 and 62 respectively. The bracket 36 can be coupled to the assembly 32 with the mounting lugs 44 and 46 overlying the lugs 56 and 58. The security screws 52 are used to firmly connect the bracket 36 to the body portion 54 so that the semi-cylindrical skirt portion 40 overlies the nut 12. The skirt portion 40 covers approximately 50% or more of the nut 12 so that it cannot be engaged by a spanner for unauthorised removal whilst the bracket 36 is in place, as shown in Figures 5 and 6.

Similarly, the check valve assembly 34 has a body portion 63 which is integrally formed with laterally extending mounting lugs 64 and 66 provided with screw holes 68 and 70 respectively, as shown in Figure 3. These enable the bracket 38 to be coupled thereto, as shown in Figures 5 and 6 by using security screws 52.

Figures 15 and 16 illustrate a novel form of security screw 52 having a broach head 72 and threaded shaft 74. The head 72 includes a projecting key portion 76 which is eccentrically mounted with respect to the head portion 72, as best seen in Figure 16. Because the screw holes 48 and 50 are countersunk, the head does not project above the surface of the lugs 44 and 46 (or lugs 64 and 66). A special tool (not shown) which is generally complementary to the broach head 72 is provided in order to remove the screws 52. The tool has a cylindrical head which can be inserted into the wider parts of the screw holes 48 and 50 and is provided with an eccentric recess which receives the key portion 76.

In summary, once the brackets have been mounted in position, using the security screws 52, as shown in Figures 5 and 6, the brackets 36 and 38 prevent unauthorised loosening or removal of the nuts 12 and 28 and hence the meter 4 cannot be removed.

Figures 80 and 81 diagrammatically illustrate a tail and nut assembly 39 which can be used in conjunction with the nut cover brackets 36 and 38. The nut and tail assembly could be used where the water meter 4 is coupled to components which do not include the laterally extending mounting lugs 56 and 58 or 64 and 66. For instance, the tail and nut assembly 39 could be used to replace the connecting sleeve 11 and nut 12 in the arrangement shown in Figure 1. The assembly 39 includes a nut 41 and threaded sleeve 43 which are functionally equivalent to the sleeve 11 and nut 12 of Figure 1. The sleeve 43 has, however, mounting lugs 45 and 47 which include threaded screw holes 49 and 51 respectively. The lugs are arranged so as to receive the security screws 52 which are used for mounting the nut cover bracket 36 diagrammatically shown in broken lines in Figure 81. In this way, the security cover 36 (or cover 38) can be coupled in a secure way to the tail 43 so that unauthorised removal of the nut 41 is prevented. Thus, the assembly 39 is a simple but effective way of improving the security of the water meter. The preferred technique for forming the tail and

nut assembly is to arrange to make the nut 41 oversize by a predetermined amount, say about 2mm, so that it can be passed over the collar 53 on the sleeve 43. Once the nut 41 is in position, it can be compressed so that it can no longer pass over the collar 53. Thus, the nut 41 is held captive between the collar 53 and the lugs 45 and 47.

Figure 7 diagrammatically illustrates a modified meter assembly 80 in which the body portion 63 of the check valve assembly 34 is integrally formed with the casing 6 of the meter 4. This would, of course, eliminate the need for the bracket 38. Alternatively, the casing 6 of the meter could be integrally formed with the body portion 54 of the cutoff valve assembly 32.

Figures 9 and 10 illustrate a modified water meter assembly 82 in which both the body portion 63 of the check valve assembly 34 and the body portion 54 of the cutoff valve assembly 32 are integrally formed with the casing 6 of the meter 4. In this arrangement because the body portions are all integral, there are no nuts 12 and 28 and hence the brackets 36 and 38 are not required.

Figures 17 to 37 illustrate in more detail the cutoff valve assembly 32. As will be described below, a number of novel features are incorporated in the cutoff valve assembly 32.

Briefly, these features include the following: i. most of the valve components are in the form of a cartridge which is slidably mounted in the valve body; ii. the valve assembly is very compact with the inlet and outlet being perpendicular; iii. a multi-function port is provided; iv. an operating handle is provided which can be locked in a number of positions; v. a slot is provided for insertion of a flow restricting body.

The cutoff valve assembly 32 includes the body portion 54, valve cartridge 84, spindle 86 and operating handle 88.

As best shown in Figure 19, the body portion 54 is integrally formed with the sleeve 11 upon which the nut 12 is mounted. The body portion 54 includes a large cylindrical bore 90 within which the valve cartridge 84 is mounted and which permits the cartridge 84 to be readily removed therefrom, as will be described below. The body portion also includes an integral threaded inlet socket 89.

The body portion 54 includes a multifunction port 92 which is normally closed by a threaded plug 94. The plug 94 is provided with eccentrically disposed recesses 96 which are configured to require a specially shaped complementary key (not shown) to be used in order to be coupled thereto for removal of the plug 94 from the port 92.

Figures 23 and 24 illustrate the components of the valve cartridge 84 in more detail.

The valve cartridge includes a main body portion 100 and a mounting portion 102 which is coupled to the main portion 100 such that it can be freely rotated relative thereto, as will be described below. The main body portion 100 is hollow and includes a rebate 104 having a rib 106 formed thereon. The mounting portion 102, on the other hand, is formed with a sleeve 108 having a recess 110 which is generally complementary to the rib 106. The main body portion 100 and mounting portion 102 are press fit together so that the sleeve 108 is expanded whereby the rib 106 enters the recess 110 and is held captive therein. In this way the mounting portion 102 is more or less permanently connected to the main body portion 100 but is freely rotatable relative thereto. The main body portion 100 includes radial inlet openings 101 and outlet 103.

The cartridge 84 includes a downstream body 112 having a sleeve 114 which overlies a skirt 116 of the main body portion 100. As best seen in Figure 20, the sleeve 114 includes a groove 118 and the skirt 116 includes a projecting rib 120. Again, the body 112 can be press fit onto the body 100 so that the rib 120 will enter the groove 118 and remain captive therein. This enables the body 112 to be freely rotatable relative to the main body portion 100. The body 112 is provided with an external groove 121 for receipt of an O-ring 122 and the main body 100 is also provided with an external groove 123 for receipt of a second O-ring 124. The 0-rings 122 and 124 seal against the inner surface of the main bore 90 so as to form

a watertight seal therewith. The mounting portion 102 is provided with threads 126 which can mesh with threads 128 provided at the mouth of the bore 90, as best seen in Figure 20.

This configuration of the cartridge 84 enables it to be slid into the bore 90 and the mounting portion 102 to be rotated in order to mesh the threads 126 and 128 in order to firmly secure the cartridge in place. This can be accomplished without rotation of the body portions 100 and 112. A gasket 130 is provided to seal against the body portion 54 and a flange 132 of the mounting portion 102, as best seen in Figure 19.

The end face of the mounting portion 102 is provided with eccentrically disposed recesses 134 which would require a special operating key (not shown) of complementary shape to be provided in order to unscrew the mounting portion 102 from the body portion 54 for removal of the valve cartridge 84.

In the illustrated arrangement, the valve cartridge 84 includes a ball valve element 140 which is provided with a wide outlet bore 142 and an inlet bore 144 perpendicular thereto, as best shown in Figures 19 and 20. Annular valve seats 146 and 148 are provided and are snugly received within the main body portion 98 and body 112 respectively. The valve seats 146 and 148 bear against the spherical outer surface of the ball valve element 140 and form a seal therewith but permit flow of water therethrough when the outlet bore 142 is fully or partly aligned with the opening in the valve seat 148. As best seen in Figure 19, the spindle 86 extends from the operating handle 88 through a bore 89 in a screw threaded mounting shoulder 150 which is threadably mounted in the main body portion 54. As best seen in Figure 31, the lower end of the spindle 86 is formed with a key 152 which in the assembled position of the valve assembly 32 is received within a keyway 154 in the ball valve element 140.

The spindle 86 is provided with a pair of grooves 156 to receive O-rings 158 to seal against the bore 89 of the shoulder 150. The upper end of the spindle 86 includes a bore 160 which allows a locking screw 162 to pass therethrough. As best seen in Figure 27, the handle 88 includes a countersunk threaded bore to enable a security screw 168 to be threaded therein and through the bore 160 in order to couple the spindle 86 to the handle 88. The screw 168

preferably is a security screw similar to the screw 52 which is used for mounting of the brackets 36 and 38 so that the handle 88 cannot be removed unless a special tool is used to first remove the screw 168.

The body 112 includes a transversely extending slot 170 which is located beneath the plug 94, as shown in Figure 19. A restriction plate 172 diagrammatically illustrated in Figures 35,36 and 37 can be inserted in the slot 170 so that the plate lies transversely across a central bore 174 of the body 112. The plate 172 is provided with a narrow orifice 176 which substantially constricts flow of water through the cartridge 84 and hence restricts the amount of water available to the service line 24 from the mains line 18. As best seen in Figure 35, the upper edge 178 of the plate 172 is curved so that its shape generally conforms to the cylindrical outer surface of the body 112. This facilitates insertion and removal of the cartridge 84 into the bore 90 when the plate 172 is in position.

Normally the plate 172 is inserted or withdrawn through the port 92 when the ball valve element 140 has been moved to a closed position. An authorised officer can then remove the plug 94 with a specially shaped tool and the plate 172 is then dropped through the port 92 into the slot 170. Preferably, the plate is made from magnetic stainless steel so that it can be removed by using a relatively strong permanent magnet to engage and withdraw the plate from the slot 170. The plate 172 could also be inserted or withdrawn when the cartridge 84 is removed from the bore 90 in an authorised way.

In order for the cartridge 84 to be removed, it is first necessary to remove the spindle 86 which would otherwise prevent sliding movement of the cartridge 84. This can be accomplished by using a specially shaped tool in order to remove the security screw 168 to enable removal of the handle 88. Once the handle 88 has been removed, a spanner can be used to engage the hexagonal body portion 190 of the shoulder 150 in order to remove the shoulder from the main body portion 54. The spindle 86 can then be removed from the body portion 54. An authorised operator would then use a special key to rotate the mounting portion 102 in order to disengage the threads 126 and 128 and then slidably remove the whole cartridge 84 from the bore 90. This enables convenient inspection and/or replacement of the

valve cartridge 84.

In contrast to known arrangements, the valve can be replaced whilst the mains pressure is still applied in the mains line 18. This would normally be accomplished by removing the plug 94 and opening the ball valve element 140. This causes water to escape through the port 92 (or fitting coupled thereto) and thus the pressure within the bore 90 is relatively low.

Because the pressure is relatively low, the cartridge 84 can be removed and a new cartridge inserted. Thereafter the valve can be closed and the plug 94 replaced.

The handle 88 is shown in more detail in Figures 25,26 and 27. It includes a vertically directed flange 200 and two locking lugs 202 and 204 provided with holes 206 and 208. As shown in Figures 17 and 18, the body portion 54 of the valve assembly includes an integral locking lug 210 having a hole 212 therethrough, the arrangement being such that the hole 212 can be aligned with one or other of the holes 206 and 208, as diagrammatically shown in Figure 18.

Figures 38 to 44 show various views of the valve assembly 32 with the handle in various orientations. In Figures 38 and 42, the valve is locked open by means of a padlock 214 which passes through the holes 208 and 212. It will be noted in this position that the other locking lug 204 overlies the plug 94 and prevents it from being removed. Figures 39 and 43 show the valve in a locked closed position. Figures 40 and 44 show the valve in an unlocked position with the plug 94 removed and a fitting 217 inserted in the port 92. The fitting 217 can be connected to a pressure gauge hose, flow meter or the like so that various testing functions can be carried out.

Figures 38 to 44 also show the valve body portion 54 fitted with a security lug 216 which is mounted on the body portion 54 by means of a security screw 218 which preferably is of the same form as the security screw 52. Only when the lug 216 has been removed by an authorised person can the handle 88 be moved to an open position when the fitting 217 is in place, as diagrammatically illustrated in Figure 41. Figure 21 shows in cross-section one form of the lug 216 and screw 218.

Figures 45 to 51 correspond to Figures 38 to 44 but show an alternative security lug 220 which is mounted so as to straddle the body portion 54 as best seen in Figures 46 and 49.

The shape of the security lug 220 is shown in more detail in Figure 22. The wider security lug 220 gives the option of having the handle 88 covering the port 92 in both the normally open and closed positions, as seen in Figures 45 and 46. A special security tool is required for removing the screw 218 in order to place the fitting 217 in the port 92 and move the valve to an open position, as diagrammatically shown in Figures 48 and 51.

Figure 52 shows an alternative valve assembly 222 which has an extended body portion 224 which includes a socket 226 for receipt of a filter cartridge 228. The filter cartridge includes a hollow cylindrical body 230 which is provided with slots 232. A filter element 234 is located within the body 230, the arrangement being such that when the filter cartridge 228 is inserted the lower end of the filter element 234 extends across the bore 90 and filters the water flowing to the sleeve 11.

Figure 53 shows an alternative form of valve assembly 236 in which the filter cartridge 238 is mounted in a socket which is generally transverse to the bore 90 of the valve element.

The filter cartridge 238 includes a slotted body 240 within which is located a filter element 242 having a lateral opening 244 therein. The body 240 is connected to a mounting portion 246 by means of a rib 248 and groove 250 which are press fit together in a similar way to the components in the valve cartridge 84. This enables the mounting portion 246 to be rotated relative to the body 240 whilst maintaining the lateral opening 244 aligned with the bore 90, as shown in Figure 53.

Figure 54 shows a still further form of valve assembly 252 which includes a butterfly valve plate 254 which is coupled to the spindle 86. The valve plate 254 is mounted in a butterfly valve cartridge 256 which is similar to the cartridge 84 and therefore need not be described in detail.

Figures 54A to 54D show a modified form of cutoff valve assembly 257 which incorporates a ball valve cartridge 259 which, in this arrangement, is mounted for vertical

positioning in the main body portion 54 of the valve assembly. This form of mounting is sometimes required by regulation and other times would be desirable where lateral access is not available such as in underground pits and the like. In this arrangement, the central bore 174 extends through the body portion 54 from an inlet fitting 261 to the connecting sleeve 11.

The bore 90 extends transversely through the body portion 54, the threads 128 being provided at the mouth for mounting of the cartridge 259.

As best seen in Figures 54C and 54D, the cartridge 259 includes a mounting cap 263 and intermediate and lower body portions 265 and 267. The cap 263 is analogous to the mounting portion 102 of the cartridge 84. It is press fit onto the intermediate body 265 by means of a groove 269 which receives a projecting rib 271 on the intermediate body 265. The cap 263 is rotatable relative to the intermediate body 265. The intermediate body also includes a rib 273 which is press fit into a groove 275 provided in the lower body 267. The intermediate and lower bodies 265 and 267 include semi-circular openings 295 and 297 which are aligned with the bore 174, as shown in Figure 54A. The bodies 265 and 267 are generally cup shaped as shown and receive opposed resilient sealing members 277 and 279. The sealing members sealingly engage the outer spherical surface of the ball 140. In this arrangement, the ball 140 includes the bore 142 which serves both as an inlet and an outlet. The bodies 265 and 267 include grooves for receipt of 0-rings 281 and 283 respectively. Figure 54C is a schematic cross-sectional view through the cartridge 259, the ball valve element 140 being omitted for clarity of illustration.

In this embodiment, the cap 263 includes a threaded bore 285 into which the shoulder 150 can be screwed, as shown in Figure 54A. The shoulder 150 holds the spindle 86 in place as in the previous embodiments. Thus in this embodiment, the cartridge 259 includes the handle 88 as well as the valve.

The sealing members 277 and 279 include laterally extending tapered part tubular portions 287 which extend laterally beyond the bore 90 and part way into the bore 174 in order to assist in sealing of the cartridge 259 in the body portion 54. The 0-rings 281 and 283 also sealingly engage the bore 90. In this embodiment, after a security tool is used to

remove the handle 88, a spanner or the like can be used to engage an integral nut 289 formed on the upper face of the cap 263. The cap 263 includes threads 291 which engage with the threads 128 at the mouth of the bore 90. As with the cartridge 84, the cap 263 can be rotated without rotating the intermediate and lower bodies 265 and 267. This enables accurate placement of the cartridge 259 in the bore and subsequent tightening and untightening of the threads. During the insertion and retraction process, the ends of the resilient tubular portions 287 will be resiliently deflected. As in the previous embodiments, rotation of the handle 88 causes rotation of the spindle 86 and consequent rotation of the ball valve element 140 so that the valve is opened when the bore 142 is fully or partly aligned with the openings defined by the tubular portions 287 of the sealing members 277 and 279.

Figure 54E is a schematic cross-sectional view through a modified vertically mounting cutoff valve cartridge 299 which can be used in the assembly 257. In this arrangement, a butterfly valve plate 254 replaces the ball valve element 140. The components which make up the cartridge 299 are shown in exploded cross-sectional view in Figure 54F. These components generally correspond to those shown in Figure 54D and therefore need not be described in detail. The valve plate 254 is rotatable by rotating the spindle 86 for opening and closing the valve.

Figures 55 to 65 illustrate in more detail the anti-backflow valve assembly 34. The assembly 34 includes a main body portion 260 which is integrally formed with a flanged spigot 262 upon which the nut 28 is press fit. The body portion 260 is provided with a central bore 264 within which can be slidably fitted, a dual check valve cartridge 266. The body 260 is integrally formed with a threaded outlet socket 268 which is at 90° to the spigot 262, thus enabling the whole assembly to be relatively compact and suitable for retrofitting.

The details of the dual check valve cartridge 266 are shown in more detail in Figures 61 to 64. The cartridge is made up of first, second, third and fourth cylindrical body portions 272,274,276 and 278. The first body portion 272 includes a flange 280 having a rib 282 which can be press fit into a groove 284 on a complementary flange 286 on the second body portion 274. This enables the body portion 272 and 274 to be permanently connected together

but be rotatable relative to one another as described above in relation to the cutoff valve assembly 32. The body portion 274 has a central plate 288 provided with four holes 290 to permit flow of water therethrough. A spindle 292 extends from the centre of the plate 288.

A first check valve element 294 includes a bore 296 which permits it to be mounted on the spindle 292. A compression spring 298 is provided and acts between the plate 288 and the rear part of the valve element 294. The valve element 294 may include a resilient washer 300. The first body portion 272 includes a valve seat 302 which, in a closed position of the valve element 294, is engaged by the resilient washer 300. The valve element 294 is held captive between the body portions 272 and 274 and is biased so that the washer 300 engages the seat 302.

The second body portion 274 includes a threaded spigot 304 which can be threaded in a socket 306 of the third body portion 276. The third body portion 276 includes a rearwardly depending skirt 308 including laterally extending outlet openings 310. The skirt 308 is provided with a projecting rib 312 which enables it to be press fit into a groove 314 on a skirt 316 of the fourth body portion 278. Again, the body portions 276 are permanently connected together but can be rotated relative to one another. The fourth body portion 278 includes a spindle 318. A second check valve element 320 is provided and it includes a recess 322 which enables it to be mounted on the spindle 318. A second compression spring 324 is provided and acts between the fourth body portion 278 and the second valve element 320.

The second valve element 320 also includes a resilient washer 326. In a closed position of the second valve element, the washer 326 sealingly engages a second valve face 327 within the third body portion 276. The second check valve element 320 is held captive between the third and fourth body portions 276 and 278. The first and third body portions 272 and 276 are provided with grooves 328 and 330 for receipt of 0-rings 332 and 334 respectively. The 0-rings sealingly engage the bore 264 of the body portion 260. The fourth body portion 278 is provided with threads 336 which mesh with threads 338 provided at the mouth of the bore 264, as best shown in Figure 56.

Mounting of the dual check valve cartridge 266 can be quickly and conveniently effected simply by pushing the cartridge 266 into the bore 264 and then rotating the fourth

body portion 278 so that the threads 336 and 338 tighten. A gasket 340 can be provided to form a seal between the fourth body portion 278 and the adjacent face of the body portion 260. The end face of the fourth body portion 278 may be integrally formed with a hexagonal nut 342 to facilitate rotation thereof.

Figure 59 shows the dual check valve in an open position. It will be seen that the first and second check valve elements 294 and 320 are clear of their respective valve seats 302 and 327. This enables water to flow into the bore 344 of the first body portion 272, through the holes 290 of the second body portion and then within the third body portion 276 and thereafter laterally through the openings 310. Water passing through the openings 310 is then free to pass into the outlet socket 268.

The dual check valves will normally be open when the pressure at the inlet is higher than at the outlet, that is to say higher within the spigot 262 than within the outlet socket 268.

If, however, the pressure falls at the inlet or increases at the outlet, backflow can be prevented by closing of the dual check valves. In this case, the springs 298 and 324 operate to move the valve elements forwardly so that they sealingly engage the respective valve faces. Figure 60 shows the valve elements in their closed positions.

The fourth body member 278 preferably includes ducts 346 which extend radially inwardly through the skirt 316. This enables the rear face of the second valve element 320 to be exposed to water pressure within the cartridge in the open position of the cartridge 266.

This has the advantage of facilitating movement of the second valve element 320 in the event that the pressure conditions change such that the valve should close.

It will be appreciated that the provision of the dual check valves in the form of a cartridge enables ready inspection and replacement of all or parts of the cartridge.

Figures 66 to 69 illustrate a test cartridge 350 which can be used in place of the dual check valve cartridge 266 for carrying out testing operations such as pressure and flow rate tests. The test cartridge 350 includes a cylindrical body portion 352 which is provided with

a skirt having a projecting rib 354 which can be press fit into a groove 356 on a complementary skirt 358 of a mounting portion 360. The mounting portion 360 includes an integral nut 362 and a threaded socket 364. The threaded socket 364 facilitates connection of test equipment to the cartridge 350. The body 352 is provided with grooves for receipt of 0-rings 366.

Figures 70 to 75 show a filter cartridge 370 which can be used in place of the dual check valve cartridge 266. The filter cartridge 370 includes a hollow body 372 having a bore 374 and slots 376. A hollow cylindrical filter element 378 is located within the bore 374.

The body 372 is provided with threads 380 and an integral nut 382. The threads 380 enable the filter cartridge 370 to be screwed into the threads 338 of the body 260.

Figures 76 to 79 diagrammatically illustrate an alternative form of anti-backflow valve assembly 390. This arrangement includes a vertically extended body 392 which can receive a dual check valve cartridge 394. The cartridge 394 includes a slotted inlet body portion 396 and the remainder of the cartridge is analogous to the cartridge 266 except that the mounting of the first and second check valve elements 398 and 400 is similar to the mounting of the second check valve element 294 of the cartridge 266. This is because in the arrangement of Figures 76 to 79, water does not need to exit laterally, as in the previous case.

It will be appreciated by those skilled in the art that the foregoing arrangements have many advantages over known arrangements. These are summarised below: Right Angle Cartridge Dual Check Valve Use part of the elbow as part of the dual check valve. The elbow is used to enable the rear check mushroom to retract past the elbow outlet during normal operation.

However, when the check is initiated by backflow or back siphonage the check closes downstream of the outlet, thus achieving the required seal.

This makes the dual check valve component short and enables dual check valve to be

retrofitted into the existing meter assembly space, that is, the space between inlet and outlet lines 18 and 24 do not need to be widened to enable the assembly to be fitted.

Cartridge design Use of the elbow enables the cartridge 84 to be accessed via the port 92 in the side of the main body enabling the cartridge to be removed for inspection or replacement without disconnecting the main body 54 from the meter 4. Existing dual check valves generally require in line connection and therefore must be disconnected to enable replacement or inspection of the dual checks.

Additional factors Casting the body as a single unit complete with boss to enable the use of an integral meter coupling nut and washer removes one joint line and negates the need for additional space which would otherwise be required to thread a separate nut and tail.

Integral meter coupling enables the meter to be positioned accurately.

The design, along with use of a test cartridge, enables in line testing of the water meter by closing of the normal outlet port and providing a female screw connect to enable a closed water source or other fittings (e. g. ball valve to be connected).

The cartridge has a unique in-out/out-in flow passage. In normal operation (in the open position) water flows through the centre of the front (upstream check) and then out the sides of the rear (downstream) component.

Cartridge design complete with cap as part of the cartridge ensures that: The dual check valve cannot be inadvertently reassembled by a plumber or householder (or during manufacture) with the checks reversed and therefore not

operational. (In current designs it is very easy to reassemble checks and insert backwards into the body).

Customers are prevented from removing the dual checks (to achieve better flow) and then replacing the cap (body 278). The cap and cartridge are connected as a single unit.

Design factors The ducts 346 in the base of the rear check (downstream component) allow: (a) Positive pressure from backflow to assist the rear check 320 to close (thus assisting the spring and ensuring positive closing pressure).

(b) The ducts 346 also prevent the creation of a vacuum in the front check recess well thus ensuring unimpeded closing.

(c) The smaller diameter rear check mushroom recess-well also increases the pressure on the reverse side of the check ensuring a positive closing pressure.

Press Metal Joints (used in both dual check valve and ball valve cartridges 84,266) (a) The press metal joint allows for the rotation of the closing cap on both the dual check valve cartridge and ball valve cartridge allowing cartridge to be screwed into the bodies without pinching, twisting or stripping from the 0-rings from their grooves.

(b) In the valve cartridge 84, the ability to rotate the cap to tighten the cartridge without rotating the cartridge body permits the spindle hole and ball to be aligned with the spindle port in the body. Without this ability to rotate the cap independent of the rest of the cartridge, the spindle hole and ball groove in the

cartridge could not be consistently aligned with the spindle port in the body (housing).

(c) The press metal fit also makes the dual check cartridge"non-tamper". The cartridge cannot be disassembled without leaving obvious indications that the press metal joints have been forced apart. This provides security in that individual cannot disassemble the product and then incorrectly reassemble the product, e. g. without springs or without checks. It also means that it provides indications of tampering where failure of the product is alleged and therefore removes the potential for false claims or post-incident rectification of non- functioning checks.

Variations: Cartridge is fabricated from brass but can be fabricated from suitable plastics or other material. The same jointing methods can be used in plastic providing the same benefits of allowing cap to rotate without stripping O-rings.

Cartridge design enables dual check valve body and water meter body to be integrated into one body.

Coupled with right angle cartridge ball valve means that complete meter assembly can be cast in a single body with no joint lines or couplings.

A body can be used to inset a mesh filter as an option of backflow if required.

Low flow and high flow or custom flow cartridges. Sizing of flow passages in checks enables a high flow or low flow configuration customised if necessary to water utility requirements.

Also allows for restriction of flow by putting orifice plate between checks, i. e. at

screw joint.

An option available is to have colour-coded gaskets on the mushroom (checks). Each calendar year the colour will be changed according to a set pattern providing a visual indication of the year in which the cartridge was manufactured. The anti-tamper aspects of the press metal fit means that the gaskets cannot be changed.

A wrap around mesh filter can be fitted over the narrow part of the rear (downstream) check.

Right Angle Cartridge Ball Valve Assemblv 32 The cartridge 84 is different from known valves which usually compress the ball and gaskets into the main body components.

This product encapsulates the ball in its own cartridge assembly separate from the body.

Right angle access to ball cartridge (or in vertical variation-top access) enables the ball valve to be replaced or serviced in-line under mains pressures. With current products there is a need to dig up the mains ferrule and/or freeze the inlet pipe to allow complete disassembly of the meter-ball valve-pipe connection to allow replacement of the whole ball valve.

Another novel aspect of the cartridge ball valve is that it includes the slot 174 which can be accessed through the multi-function port 172 in the main body.

The use of a removable orifice plate 172 to reduce water flow is novel. Existing methods include insertion of nut and tails with restriction orifices; the insertion of a restriction plug in the upstream side of the water meter connection, or the adjustment of the meter stop cock to the required level of flow and then covering the stopcock and

meter with a security box to prevent access.

Multifunction port 172 This could also be applied as a stand alone fitting or as part of a water meter inlet connection.

The multifunction port 172 allows access to insert and remove restriction plates but it can also be used to: (a) Import of emergency water (b) Test of water meters (in conjunction with RADCV test cartridge) (c) Draw water for analysis (d) Pressure testing of flow to customer The multifunction port 172 enables water utilities to charge for emergency water.

Currently water utilities use the customers first hose tap to import water into customer service line thus bypassing the meter. With the use of the multifunction port, water is still provided downstream of the meter and can therefore be recorded by the customer's meter tap.

Design factors As with dual check valve integral meter connections save the space otherwise required to thread a separate nut and tail to connect ball valve to meter. Without this integration of coupling and ball valve it would be difficult to obtain the space required for orifice plate (and multifunction port) within the normal meter connection space.

As press metal fitting of components allows for alignment of the orifice port and restriction plate slot with the restriction port in the main body.

Security and safety handle 88. The handle 88 has been designed so that the ball valve must be in the OFF position (or in the water utility ON position) to gain access to the multifunction port plug 94. Thus if an unauthorised connection is made by screw fitting into the multifunction port, the handle cannot be returned to the ON position since the fitting prevents the handle rotating one way an a removable lug prevents it rotating the other way.

The ball valve operation with a security head screw and security lug enables the water utilities to connect a hose into the multifunction port 92 and then by removing the security screw with the special broach tool to turn the ball valve to the alternative ON position. The security lug is fitted using the broach head screw also used for security brackets. Once a fitting is connected into the multifunction port the security lug must be removed to allow the handle to be rotated to the ON position.

The handle design also allows the handle to be locked in the OPEN position which means that the handle covers the restriction port. This gives water utilities that are restricting customers an additional way (apart from the security broach cap) of preventing access to the multifunction port.

Multifunction port plug 94 can be lefthand threaded for additional security.

Variations Vertical cartridge ball valve with cartridge inserted from top Butterfly valve version Standard dirt box version with cartridge and multifunction port modified to allow

integral filter to be fitted.

Vertical dirt box version Securitv Brackets and Broach Head Security Screws Security brackets 36 and 38 can be fitted to the security lugs built into the body of both the dual check valve and ball valve. The brackets cover the coupling nut thus preventing the meter connection from being uncoupled and preventing theft of water or reversing of the meter (to wind back the meter reading).

The brackets are connected with special broach head screws requiring a special tool to tighten and loosen them. As an added security measure, the screws are lefthand thread.

The bracket concept has a wider application. There are many applications where for safety, security or control there is a requirement to prevent a coupling from being disconnected. For example, the brackets could be modified to allow fitting of a padlock through the bracket and security lug through one of the two screw holes so that a key-locked control system could be used to control access to certain couplings within a factory.

Many modifications will be apparent to those skilled in the art without departing from the spirit and scope of the invention.