I AUSTRALIA FB RICE & CO Patent and Trade Mark Attorneys Patents Act 1990 GLOBAL VALVE TECHNOLOGY LIMITED COMPLETE SPECIFICATION INNOVATION PATENT Invention Title: Testable water meter The following statement is a full description of this invention including the best method of performing it known to us:- 2 Cross-Reference to Related Applications The present application claims priority from Australian Provisional Patent Application No. 2009906326, filed 18 December 2009, the content of which is incorporated herein by reference. 5 Field The present disclosure relates to a testable water meter. Background 10 Conventionally, there are several water meter designs, which can be broken down into two categories: A. Water meters with moving parts; and B. Water meters without moving parts. There are few known water meters with moving parts that are fully testable. 15 One example is US 5,559,289, currently assigned to Neptune Technology Group, which provides test ports in the housing to enable the housing unit to be tested for valve leaks. Examples of water meters without moving parts are US 2007/022823 and US 7,472,605, owned by Sentec Limited, UK, which provide a magnetic transducer for 20 measuring the flow of a fluid. These meters are claimed to be able to detect reverse flow (down to relatively small volumes) and, in response, to flag an immediate alarm through a radio network. A disadvantage of these meters, however, is that they do not provide a means of testing the fluid flow detection components of the meter. Further disadvantages are that these meters do not provide backflow control and would provide 25 no protection in the event of signal failure. The importance of a water meter device being testable becomes apparent as water regulatory authorities become more focused on monitoring the distribution of water within networks for economic and environmental reasons. In such, the water authorities are responsible for the quality and functionality of water meters within their 30 allocated jurisdiction. Known water meters typically must be removed from a plumbing circuit for testing. This disadvantageously results in the water meter having to be removed and replaced with another meter to maintain water supply. Moreover, the removed water meter must then be taken to a suitable qualified facility for testing. Given the very large 35 numbers of water meters currently installed, the financial burden placed on water regulatory authorities in testing and servicing these meters is very high.
3 As the price of water rises to balance supply and demand, the issue of accuracy of measurement of water flow becomes of greater commercial and legal significance. Accordingly, there is an increasing demand to ensure that volume of usage is accurate. Measurement of the accuracy of a conventional water meter and testing the operation of 5 its non-return valves is a tedious, time consuming and costly task. Summary In a first aspect, the present disclosure provides a testable water meter comprising: 10 a housing; a fluid conduit extending through the housing, the conduit having an inlet on an upstream end and an outlet on a downstream end; a flow detector intermediate the inlet and the outlet for detecting a volume of flow of a fluid passing through the conduit; 15 one or more valves for controlling flow through the conduit; and a plurality of test ports communicating with the conduit, wherein the test ports are positioned to allow for isolation and testing of one or more of: the flow detector, the valves individually, 20 the valves as a group, and the meter overall. One of the test ports may be associated with an upstream end of each of the valves and another of the test ports may be associated with a downstream end of each of the valves to allow for isolated testing of each of the valves. 25 One of the test ports may be associated with an upstream end of the flow detector and another of the test ports may be associated with a downstream end of the flow detector to allow for isolated testing of the flow detector. The one or valves may comprise one or more check valves for inhibiting backflow of fluid. 30 The test ports may be positioned to allow for isolation and testing of all of: the flow detector, the valves individually, the valves as a group, and the meter overall. 35 The flow detector and the valves may be aligned along a substantially linear axis.
4 The test ports may be adapted to receive test cocks. In other embodiments, the test ports may be adapted to receive pressure sensing devices, including pressure transducers, piezoresistive devices, strain gauges, capacitive devices (absolute, differential and gauge), electromagnetic devices, piezoelectric and potentiometric 5 devices. Brief Description of the Drawings Embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: 10 Figure 1 illustrates an axonometric view of a first embodiment of the present disclosure; Figure 2 illustrates a side elevation of the embodiment of Fig. 1; Figure 3 illustrates a sectional view of the embodiment of Fig. 2, with a mechanical flow detector and dual check valves; 15 Figure 4 illustrates a sectional view of a second embodiment of the present disclosure, with a mechanical measuring element and a single check valve; Figure 5 illustrates a sectional view of a third embodiment of the present disclosure, with an electromechanical flow detector and dual check valves; Figure 6 illustrates a sectional view of a fourth embodiment of the present 20 disclosure, with an electromechanical flow detector and a single check valve; Figure 7 illustrates a sectional view of a fifth embodiment of the present disclosure, with a mechanical flow detector, dual check valves and with miniature load cells positioned in the test ports; Figure 8 shows a sectional view of a prior art flow meter, illustrating its fluid 25 path; and Figure 9 is a graph comparing performance, in terms of pressure loss, of the prior art water meter of Figure 7 and the meter of Figures 1-3. Detailed Description 30 Figures 1 and 2 illustrate a testable water meter 100 having a housing I with a conduit 2 extending therethrough and defining an inlet 3 and an outlet 4 positioned along a central axis of flow A. A mechanical flow detector 5 is located intermediate the inlet 1 and the outlet 2 for detecting a volume of flow of a fluid passing through the conduit 2. 35 Figure 3 illustrates an upstream test port 6 associated with an upstream end of the flow detector 5 by being located between the inlet 3 and the flow detector 5, and a 5 first intermediate test port 7 associated with a downstream end of the flow detector 5 by being located downstream of the flow detector 5. The positioning of test ports 6 and 7 on either side of the flow detector 5 allows the flow detector to be isolated for testing by physically measuring, via the test ports 6 and 7, the flow of a fluid through the flow 5 detector 5. Figure 3 also illustrates a second intermediate test port 8 associated with a downstream end of a casing seal 9 of a first check valve 10 by being located downstream thereof. The second intermediate test port 8 is used in conjunction with the first intermediate test port 7, which is associated with an upstream end of the first check 10 valve 10, to test the forward flow and reverse flow of the first check valve 10. Figure 3 also illustrates a downstream test port 11 associated with a downstream end of a casing seal 12 of a second check valve 13 by being located downstream thereof. The downstream test port 11 is used in conjunction with the second intermediate test port 8 to test the forward flow and reverse flow of the second check 15 valve 13. Testing of the combined operation of check valves 10 and 13 is achieved using test port 7 in conjunction with test port 11. Similarly, testing of the overall water meter is achieved using the most upstream test port, which is test port 6, in conjunction with the most downstream test port, which is test port 11. 20 In the illustrated embodiment, the test ports are formed in the housing 1 and are fluid flow communicable with the conduit 2. It should be appreciated that the test ports 6, 7, 8 and 11 can be attached to a removable external flow and pressure reading device via mechanical threads or other methods of attachment. It should also be appreciated that the test ports 6, 7, 8 and 11 may be replaced by 25 electromechanical elements for registering pressure and these elements may have sections exposed above the surface of the water meter housing 1 providing contact points for attachment to a removable external flow and pressure reading device of a different design. For example, the test ports 6, 7, 8 and 11 may be adapted to receive test cocks, 30 or pressure sensing devices, including pressure transducers, piezoresistive devices, strain gauges, capacitive devices (absolute, differential and gauge), electromagnetic devices, piezoelectric and potentiometric devices. Figure 4 illustrates a cross-section through an alternative embodiment similar to that of Figures 1-3, where corresponding reference numerals indicate corresponding 35 components with corresponding functionality. In the Figure 4 embodiment, however, a single check valve 10 is provided.
6 It should be understood that standards and codes vary from country to country, and sometimes state to state, and a single check valve design of Figure 4 may be applied to those jurisdictions whose standards do not require a dual check valve assembly. 5 Figure 5 illustrates a sectional view of an embodiment similar to that of Figures 1-3, where corresponding reference numerals indicate corresponding components with corresponding functionality. In the Figure 5 embodiment, however, an electromechanical flow detector 50 is used to replace the mechanical flow detector 5 of Figures 1-3. As can be seen from Figure 5, the inlet 1 and outlet 2, along with the flow 10 detector 50 and the upstream and downstream check valves 10 and 13, are positioned along a central axis of flow. Figure 6 illustrates a further embodiment, similar to that of Figure 5, where corresponding reference numerals indicate corresponding features with corresponding functionality. In the Figure 6 embodiment, however, a single check valve 10 is 15 provided. As with the embodiment of Figure 4, the Figure 6 embodiment may be applied in jurisdictions where standards do not require a dual check valve assembly. Figure 7 illustrates a further embodiment, similar to that of Figures 1-3, where corresponding reference numerals indicate corresponding features with corresponding 20 functionality. In the Figure 7 embodiment, however, the test ports 6, 7, 8, and 1 1 are internal and house miniature load cells for sensing fluid flow, which can communicate with external devices via cabling extending through the housing 1. It will be appreciated that similar internal test ports could be provided in the embodiments of Figures 4-6. 25 Figure 8 is provided for comparison and shows a sectional view of a prior art flow meter, illustrating a path of fluid as it would flow through the flow meter. It will be appreciated from a comparison of any one of Figures 3, 4, 5 or 6 with Figure 8 that the Figure 3-6 embodiments represent a significant simplification and improvement in design and manufacturability compared to the prior art. 30 It should be noted that it is typical in most commercial water meter installations around the world to provide cut-off valves upstream and downstream of water meters. In residential water meter installations, there is typically a cut-off valve upstream of the water meter. Thus, cut-off valves 37 and 38 on the water meter, as shown in the prior art example of Figure 8, are not generally required. 35 Figure 9 is provided for comparison and shows a graph comparing performance, in terms of pressure loss, of the prior art water meter of Figure 8 and the meter of 7 Figures 1-3. Figures 8 and 9 provide a clear representation of the improved performance of the testable water meter of Figures 1-3 over the prior art meter of Figure 8. It will be appreciated by persons skilled in the art that numerous variations 5 and/or modifications may be made to the specific embodiments described above with reference to the drawings without departing from the broad general scope of the present disclosure. The above embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.