WO2000014489A1

WO2000014489A1 - A device for eliminating air in a water flow measuring system

Info

Publication number: WO2000014489A1
Application number: PCT/GB1999/002744
Authority: WO
Inventors: Rodney Wild
Original assignee: Rodney Wild
Priority date: 1998-09-02
Filing date: 1999-09-02
Publication date: 2000-03-16
Also published as: GB9818974D0; AU5633699A

Abstract

Apparatus for eliminating air in a water flow measuring system (1) comprises a housing (11) defining a flow chamber (12) having a water inlet (13) for connection to a water supply line and an outlet (14) for connection to a water feed line (7) connected to a water meter (8). The water inlet (13) and water outlet (14) are arranged such that all water flowing from the inlet (13) to the outlet (14) must flow through the chamber (12). An air outlet (16) is arranged above the water outlet (14) and a floating valve member (17) is constrained within the chamber (12) so as in use to move with the water level in said chamber (12) between an upper position in which it closes said air outlet (16) and a lower position in which air is permitted to vent through said air outlet (16).

Description

A DEVICE FOR ELIMINATING AIR IN A WATER FLOW MEASURING SYSTEM

This invention relates to a device for eliminating air in a water flow measuring system and to a water flow measuring system incorporating such a device.

It is well known to meter the flow of water to domestic or business premises, the intention being that the water user receives a water bill which accurately reflects their water usage. However, a problem with known water meters is that air passing through the meter will also be metered. This is particularly a problem in circumstances in which there is an interruption in the water supply in which case solely air may flow through the meter. Although it is clearly undesirable for the water meter to meter air, with the result that the customer pays for water it has not had, there is generally no provision made for effectively venting air upstream of the water meter.

It is an object of the present invention to obviate or mitigate this disadvantage.

According to a first aspect of the present invention the is provided apparatus for eliminating air in a water flow measuring system, the apparatus comprising a housing defining a flow chamber, a water inlet for connection to a water supply line, a water outlet for connection to a water feed line connected to a water meter, the water inlet and water outlet being arranged such that all water flowing from the inlet to the outlet must flow through the chamber, an air outlet arranged above the water outlet, and a floating valve member constrained within the chamber so as in use to move with the water level in said chamber between an upper position in which it closes said air outlet and a lower position in which air is permitted to vent through said air outlet.

Preferably the water inlet is arranged to direct incoming water/air in an upwards direction into the chamber.

In preferred embodiments the water inlet opens into the bottom of the chamber and the air outlet is located directly above the water inlet.

The water inlet preferably defines an annular seat on which the valve member sits when in its lowermost position with no water within the chamber.

In one embodiment of the invention the annular seat of the water inlet is chamfered so as to taper upwards and outwards, and a portion of the valve member which seats on the inlet is correspondingly tapered, the arrangement being such that in use with no water in the chamber any incoming air will lift the valve member slightly from the annular seat and will be directed upwards into the chamber around the valve member through an annular gap defined between the tapering faces of the inlet and the valve member.

Grooves or other formations may be provided on the tapered surface of the water inlet seat and/or tapered surface of the valve member to prevent an air tight seal being formed between the two.

Preferably an upper portion of the valve member is provided with a compression seal member which forms a seal with an annular seat of the air outlet when said valve member is in its uppermost position.

The water outlet preferably opens into the bottom of the chamber adjacent said water inlet.

In one preferred embodiment the water outlet comprises a water outlet passageway the upstream end of which opens into the side of said housing diametrically opposite said downstream opening of the inlet passageway.

According to a second aspect of the present invention there is provided a water flow measuring system comprising a pressurised water supply line, a water meter incorporated in said supply line, and a device according to any preceding claim for eliminating air incorporated in said supply line upstream of said water meter.

A specific embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1. is a diagram of a water flow measuring system according to the present invention;

Fig 2. is a vertical section through an air eliminating device according to the present invention;

Fig. 3. is a vertical cross-section of the device of Fig. 2. looking in the direction of arrow A on Fig. 2.;

Fig. 4. is a plan view from above of the device of Fig. 2 and Fig. 3; and

Fig. 5. corresponds to Fig. 2 but illustrates the floating valve member in an uppermost position.

Referring to Fig. 1 of the drawings, a water flow measuring system indicated generally at 1 comprises a pressurised water supply line 2 which branches from a main supply 3 and comprises a first section 4 connecting the main supply to the customer's premises and incorporating the usual local authority stop valve 5 and the consumers stop cock 6, a feed section 7 for feeding water to a water meter 8 of conventional design (and which will not be described in further detail), and a feed section 9 for feeding metered water to the consumers distribution system. The flow of water and air through the system is indicated by the black and white arrows respectively. In a conventional supply system there is a possibility that air travelling through the system will operate the meter 9 with the result that the consumer will be charged for water which it did not receive. However, in accordance with the present invention an air eliminating device 10 (illustrated schematically in Fig. 1) is installed in the water supply line upstream of the feed section 7. The air eliminating device 10 is described in more detail below.

Referring to Figs. 2 to 5, the air eliminating device 10 comprises a generally cylindrical housing 11 which defines a float chamber 12 above inlet and outlet passages 13 and 14 respectively. The top of the chamber 12 is sealed by a cap 15 which is provided with a central air outlet 16.

The inlet passageway 13 comprises a circular upstream opening 13a in a side of the housing 11, a substantially horizontal upstream portion 13b which extends beneath the chamber 12 and a substantially vertical portion 13c which opens centrally into the bottom of the chamber 12 directly beneath the air outlet 16. The mouth of the opening 13c is chamfered defining an annular seat with tapering sides. The outlet passageway 14 comprises a upstream opening 14a which communicates with the chamber 12, and a downstream substantially horizontal portion 14b which opens at a circular opening 14c in the side of the housing 11 diametrically opposite the opening 13a of the inlet passage 13. The openings 13a and 14c are arranged so that the device 10 may be readily installed in-line in an existing water supply line as illustrated in Fig. 1.

A generally cylindrical valve member 17 is constrained to float within the chamber 12 between a lowermost position in which it sits in the inlet opening 13c (illustrated in Fig. 1), and an uppermost position in which it closes the air outlet 16 (illustrated in Fig. 4). The valve member has an inwardly tapered bottom portion 17b which sits upon the chamfered annular seat defined by the inlet opening 13c when in its lowermost position as illustrated in Fig. 1. The tapered portion 17b of the valve member 17 is provided with generally axial grooves 18 which prevent an air tight seal being formed between the valve member and the chamfered seat of the opening 13c. The upper end of the floating valve member 17 is provided with a central spigot 19 which provides a seat for an annular sealing member 20, which may be made from rubber or a similar material suitable for forming a compression seal.

In normal operating conditions, with water flowing through the supply line 2, water will enter the device 10 through the inlet passage 13 and will be directed upwardly into the chamber 12. Water within the chamber 12 will cause the floating valve member to lift from the position illustrated in Fig. 1. From the chamber 12, water will exit via the outlet passageway 14. Water cannot exit via the air outlet 16 since as the water level rises within the chamber 12, the floating valve member will float upwardly to the position illustrated in Fig. 4 in which the spigot 18 is received within the opening 16 and the sealing member 19 abuts against the rim of the opening 16 forming a water tight seal. Thus it will be seen that in the normal conditions water will flow through the inlet passageway 13, into the chamber 12, and then out of the chamber 12 through the outlet passageway 14.

However, should the water supply be interrupted the floating valve member 17 will fall thus opening the air outlet 16. Any air which enters the device through the inlet 13 will be directed upwardly into the chamber 12 between the tapered surfaces of the inlet opening 13c and the bottom portion 17b of the floating valve member 17. Whilst air pressure may be sufficient to lift the valve member 17 enough to allow the air to flow through the inlet 13c the incoming air will not raise the valve member 17 to close the air outlet 16. Rather, air entering the inlet 13 will be directed by the chamfered opening 13c and the tapered portion 17b of the valve member upwardly past the valve member 17 and towards the air outlet 16 from which it will be vented. Tests have shown that because the inlet 13, and inlet opening 13c, are arranged to direct air upwardly into the chamber, virtually no air flows through the chamber to the outlet passageway 14a under pressures which might conceivably be encountered in practical situations. The grooves 17c in the tapered portion 17b of the valve member 17 prevent an air tight seal being formed between the inlet opening 13c and the valve member 17 in "suck-back" conditions, which might otherwise obstruct proper operation of the device.

Claims

1. Apparatus for eliminating air in a water flow measuring system, the apparatus comprising a housing defining a flow chamber, a water inlet for connection to a water supply line, a water outlet for connection to a water feed line connected to a water meter, the water inlet and water outlet being arranged such that all water flowing from the inlet to the outlet must flow through the chamber, an air outlet arranged above the water outlet, and a floating valve member constrained within the chamber so as in use to move with the water level in said chamber between an upper position in which it closes said air outlet and a lower position in which air is permitted to vent through said air outlet.

2. A device according to claim 1 , wherein the air outlet is located above the water inlet.

3. A device according to claim 2, wherein the water inlet is arranged to direct incoming water/air in an upwards direction into the chamber.

4. A device according to claim 3, wherein the water inlet opens into the bottom of the chamber and the air outlet is located directly above the water inlet.

5. A device according to claim 4, wherein the water inlet defines an annular seat on which the valve member sits when in its lowermost position with no water within the chamber.

6. A device according to claim 5, wherein the annular seat of the water inlet is chamfered so as to taper upwards and outwards, and a portion of the valve member which seats on the inlet is correspondingly tapered, the arrangement being such that in use with no water in the chamber any incoming air will lift the valve member slightly from the annular seat and will be directed upwards into the chamber around the valve member through an annular gap defined between the tapering faces of the inlet and the valve member.

7. A device according to claim 6, wherein grooves or other formations are provided on the tapered surface of the water inlet seat and/or tapered surface of the valve member to prevent an air tight seal being formed between the two.

8. A device according to any one of claims 1 to 7, wherein the water inlet comprises an inlet passage a downstream end of which opens into a side of the chamber for connection to the water supply line and the upstream end of which defines said water inlet, the downstream portion of the inlet passageway being substantially horizontal and the upstream portion being substantially vertical.

9. A device according to any preceding claim, wherein an upper portion of the valve member is adapted to sealingly engage an annular seat defined by the air outlet.

10. A device according to claim 9, wherein said upper portion of the valve member is provided with a compression seal member which forms a seal with said annular seat of the air outlet when said valve member is in its uppermost position.

11. A device according to any preceding claim, wherein the water outlet opens into the bottom of the chamber adjacent said water inlet.

12. A device according to any preceding claim, wherein the water outlet comprises a water outlet passageway the upstream end of which opens into the side of said housing diametrically opposite said downstream opening of the inlet passageway.

13. A water flow measuring system comprising a pressurised water supply line, a water meter incorporated in said supply line, and a device according to any preceding claim for eliminating air incorporated in said supply line upstream of said water meter.

14. A device for eliminating air in a water flow measuring system, substantially as hereinbefore described, with reference to the accompanying drawings.

15. A water flow measuring system, substantially as hereinbefore described, with reference to the accompanying drawings.