Cross Reference

This application claims priority from Australian Provisional Patent Application No. 2009905909 filed on 3 December 2009, the contents of which are to be taken as incorporated herein by this reference.

Field of the Invention

The present invention relates to a fluid control device and to a fluid control system. More particularly, the invention relates to a fluid control device for controlling the flow of fluid into and out of a fluid reservoir, such as a water tank.

Background of the Invention

The current ongoing water shortage in the majority of Australian cities has led to severe water restrictions and a subsequent increase in awareness of water usage by the public. As a result, the implementation of dedicated water reticulation networks to enable the use of recycled stormwater in new residential housing developments has become popular in recent years. The recycled water may be used for watering gardens, in the laundry and for flushing toilets.

Typically it is not economically viable to install dedicated reticulated recycled water networks in existing suburbs as a retrofit. This is because in established suburbs it is far too costly to dig trenches and lay new water pipe systems solely for the purpose of supplying recycled water to households. However, it has now been recognised that reticulated recycled water networks could be provided to established suburbs using directional boring technology rather than the traditional pipe laying techniques. However, for this to be economically viable, small diameter plastic water pipes must be used to minimise the size of bores that need to be drilled. The use of such small diameter pipe significantly restricts the water pressure and flow rate of the recycled water available at individual properties and hence the effective use of the recycled water. Another difficulty in increasing consumer's reliance on recycled water is to ensure that there is adequate supply. It is recognised that a huge volume of stormwater (and hence potential recycled water) is lost each year because of the inability to capture and store the stormwater during peak flows. Hence that stormwater is typically allowed to flow out to sea. For example, in some jurisdictions stormwater runoff is collected through wetland systems and then processed in a water processing plant. The processed water is then pumped into an underground aquifer for later use in reticulated recycled water networks. During times of peak rainfall, much of the stormwater runoff is wasted and flows out to sea simply because the water inflow to the wetlands is greater than the processing capability of the associated water processing plant. It would be advantageous to address this problem.

The present invention seeks to address at least one of the above mentioned problems and disadvantages.

The discussion of the background to the invention herein is included to explain the context of the invention. This is not to be taken as an admission that any of the material referred to was published, known or part of the common general knowledge as at the priority date of this application.

Summary of the Invention

According to a first aspect of the present invention there is provided a fluid control device for connection to a fluid reservoir, said fluid control device including an inlet valve for providing fluid to the reservoir from a common supply, a fluid dump mechanism for dumping fluid from the reservoir to a fluid collection system, means for detecting the amount of fluid in the fluid reservoir and control means for controlling operation of the inlet valve and the fluid dump mechanism so that the fluid in the reservoir can be maintained at a set level.

The fluid control device is arranged so that fluid from a common supply can be provided to the reservoir when the fluid in the reservoir is below the set level. The supplied fluid is then stored in the reservoir and may be used by a user as required. Additionally, if the fluid in the reservoir is above the set level, for example because the reservoir is fed by an alternative source, the fluid control device is arranged so that fluid may be dumped, when appropriate, from the reservoir to the fluid collection system.

The control means may use different inputs to control operation of the device. For example, the inputs may include but are not limited to a level of fluid in the reservoir detected by the detecting means, the state of the inlet valve, the state of the dump mechanism and/or any associated outlet valve, user inputs, authority inputs and any other inputs necessary to operate the fluid control device in accordance with a desired control strategy.

The control means may also include in certain preferred embodiments means to provide a time delay on the operation of the inlet valve and/or the fluid dump mechanism.

The detecting means typically includes means for detecting the volume or level of fluid within the reservoir.

The set level of the reservoir may be controlled and set by the user (i.e. user-set level). The "set level" may be, for example, a particular height of fluid or range of heights of the fluid in the reservoir or a particular volume of fluid or range of volumes of fluid in the reservoir. It will thus be understood that the term "set level" is not intended to be limiting to a single value but may include a range of values.

The user has the ability to vary the "set level" for the fluid in the reservoir. In this way different volumes or ranges of different volumes of fluid can be normally stored in the reservoir. Alternatively, or in addition thereto, another party may be able to control the set level of the fluid in the reservoir. For example, the authority responsible for the common supply or the fluid collection system may have the ability to control the set level. By varying the set level it is possible to control the amount of liquid supplied to the reservoir from the common supply and also to release fluid from the reservoir into the fluid collection system. The fluid collection system may direct the fluid out to another location or more preferably to a fluid processing system and/or storage system before passing that fluid into the common supply for redistribution.

In a preferred form of the invention the reservoir is further arranged to receive liquid from an alternative supply. That supply may be any source but typically would be a runoff supply, for example the reservoir may include an inlet for receiving runoff water from a roof of a building or other surface. The reservoir may also include an overflow outlet for allowing liquid to flow out of the reservoir when it has reached maximum capacity.

The fluid control device may be arranged so that the dump mechanism can be manually operated by the user or another authority to dump fluid from the reservoir or alternatively, an automatic means may be provided to control the dump mechanism. A manually operated mechanism may include a mechanical arrangement such as a handle, latch or lever that is operated by the user to move the dump mechanism to an open (dump) configuration when desired. An automatic means may cause the control means to open the dump mechanism when a remote input is received, a full reservoir input is received or inflow through an alternative supply inlet is detected (e.g. inflow to the reservoir via the alternative supply inlet due to a rain storm). The automatic means may include a time delay feature to delay operation of the automatic means until a certain time after the inputs are detected.

It is preferred that the dump mechanism is arranged to automatically return to a closed (non-dump) configuration following the required fluid release. The dump mechanism may adopt different forms but typically includes a dump valve.

The term "reservoir" as used throughout this document should be understood to include any storage vessel including but not limited to conventional household rainwater tanks, fluid bladders, pipes, ponds, dams and other fluid storage systems. The term "common supply" as used throughout this document should be understood to include a fluid supply such as a water supply that is commonly delivered to a number of users. For example, such a water supply may be reticulated water supply provided by a water authority or a local Council. The water supply may, for example be drinking quality water or recycled water that is not normally certified as drinking quality.

The term "fluid collection system" as used throughout this document should be understood to include, but is not limited to, systems such as stormwater collection and runoff systems. The aim of these systems is typically to capture and channel fluid runoff (for example stormwater) to a further location.

The fluid control device of embodiments of the invention may include different capabilities and features depending on, for example, the needs of the user, the needs of the authority responsible for the common supply, the needs of the authority responsible for the fluid collection system and the needs of other interested parties. For example, flow meters may be included to measure and/or record the flow of fluid through the inlet valve, the flow of fluid dumped from the reservoir, the flow of fluid into the reservoir from an alternative supply and/or the flow of fluid through the overflow outlet. The flow meters may, for example be of a mechanical or electronic type. The data generated by such flow meters may be transmitted via a data communication means to, for example, interested parties. Interested parties may include the user, the authority responsible for the common supply or other entities (e.g. an invoicing entity). The supplied data may be used to allow the user to be charged or credited for fluid used or supplied back into the fluid collection system.

A simple form of data communication means that could be used is a mechanical flow meter with a mechanical fluid volume display. Another form of data communication means is an electronic flow meter with a digital readout display located on the fluid control device, adjacent thereto or remotely at a more convenient location. Another form of the data communication means is a remote connection with an external data receiver.

Another embodiment of the invention is a mechanical device that employs a float actuation of the inlet valve and dump mechanism. The float may be located inside the reservoir and the set level of the reservoir may be adjusted by varying the float height of the float.

A fluid control device according to one embodiment of the invention may be a fully electronically controlled device. Electric actuated valves such as solenoid or electric motor operated valves may be used for both the inlet valve and the dump mechanism. An electronic sensor such as a pressure sensor, float switch or similar may be used to detect the amount of the fluid in the reservoir. An electronic flow meter may be employed to measure the volumetric flow or flow rate of fluid through the valves. A microprocessor may be employed as the control means to control all of the components of the control device. User and authority inputs to adjust the set level of the fluid in the reservoir may be provided by external inputs.

A fluid control device according to another embodiment of the invention may be a mechanical diaphragm operated device. In accordance with such an embodiment, a diaphragm is mechanically connected to an actuating means for actuating both the inlet valve and the dump mechanism. Fluid pressure on one side of the diaphragm is opposed by force, for example a spring force, applied to the other side of the diaphragm. Fluid pressure caused by fluid in the reservoir acts on the diaphragm producing a force that is used to control the operation of both the inlet valve and the dump mechanism. A pre-load on the spring is adjustable by the user or another authority so as to set the desired set level of the fluid in the reservoir.

The present invention also provides in a second aspect a fluid control system including a common fluid supply, at least one fluid control device connected to a fluid reservoir, said fluid reservoir may also be arranged to receive fluid from an alternative fluid supply, and a fluid collection system, said fluid control device including an inlet valve for providing fluid to the reservoir from the common supply, a fluid dump mechanism for dumping fluid from the reservoir to the fluid collection system, means for detecting the amount of fluid in the fluid reservoir and control means for controlling operation of the inlet valve and the fluid dump mechanism so that the fluid in the reservoir can be maintained at a set level.

The fluid control device is preferably arranged so that in certain circumstances the volume of the fluid in the fluid reservoir is temporarily increased above a "normal" volume that is determined by the set level of the fluid in the reservoir. This arrangement is provided in order for the reservoir to temporarily hold additional fluid than would otherwise normally be stored in the reservoir. Such a circumstance might occur during high storm periods wherein the alternative fluid supply into the reservoir is runoff rain water and it is not desirable to dump water in the reservoir into the fluid collection system because that system is at or near capacity. This arrangement would allow the additional water to be dumped to the fluid collection system at a more favourable time.

According to the present invention there is also provided a method of collecting flow readings of fluid through a fluid control device in accordance with an earlier aspect of this invention, the method including the steps of:

a) determining a first reading of fluid through the control device;

b) determining a second reading of fluid through the control device;

c) determining a verification code generated by the fluid control device; and

d) providing the first reading, the second reading and the verification code to an authority.

The first reading is preferably representative of the amount of fluid passing into and through the fluid control device from a common supply. The second reading is preferably representative of the amount of fluid dumped from a reservoir connected to the fluid control device to a fluid collection system. The verification code is preferably generated using an algorithm based on the first and second readings.

The method of collecting flow readings may also include the step of: e) using the verification code to verify the accuracy of the provided first and second readings.

It is envisaged that the steps of determining the first and second readings and the verification code would be performed by an end user. The end user would provide the first and second readings and the verification code to an authority. That or another authority would then verify the accuracy of the provided first and second readings based on the verification code and may then take another action step. That action step may be, for example, to query the first and second readings provided by the user, to record the readings for future use or to arrange invoicing to the user of fluid usage based on the provided first and second readings (e.g. the end user would be invoiced for water usage from the common supply less any water dumped from the reservoir to the fluid collection system).

It is envisaged another party other than the user may provide any of the first reading, second reading or verification code.

It should also be understood that although the invention is particularly relevant to the storage of water and the supply of recycled water to a user from a common supply, it is not limited thereto.

Description of the Drawings

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

Figure 1 is a schematic representation of a fluid control system in accordance with a first embodiment of the invention; Figure 1 A is a schematic representation of a variation of the fluid control system shown in Figure 1 ;

Figure 2 is a schematic representation of a fluid control system in accordance with a second embodiment of the invention;

Figure 3 is a schematic representation of a fluid control system in accordance with a third embodiment of the invention;

Figure 4 is a cross-sectional view of a fluid control device according to a fourth embodiment of the invention. The inlet valve is shown in the open position and the dump valve is shown in the closed position;

Figure 5 is a view similar to Figure 4 but illustrating the inlet valve in the closed position and the dump valve in the open position;

Figure 6 is a partial external view of the fluid control device shown in Figure 4 illustrating the dump valve cam latch;

Figure 7 is a schematic representation of a hysteresis mechanism of a fluid control device in accordance with an embodiment of the invention;

Figure 8 is a partial cross-sectional view of the hysteresis mechanism of the fluid control device shown in Figure 4;

Figure 9 is an enlarged view of the flow meter of the fluid control device shown in Figure 4; and

Figure 10 is a top view of the fluid control device shown in Figure 4. The flow meter LCD display and height adjustor knob are better visible in this view. Detailed Description of the Preferred Embodiments

For ease of the following description, the preferred embodiments of the invention will be described in the context of water storage and delivery. Hence the "fluid" of the preferred embodiments is water. However, it is again reiterated that the present invention is not intended to be limited to "water" applications.

Figure 1 shows a fluid control system 20 in accordance with a first embodiment of the invention that is hereafter referred to as an "electronic design". The control system 20 is connected to a common fluid supply CS such as a supply of recycled water from a reticulated system that is supplied to the user's home. The control system 20 is also connected to a fluid collection system FC (e.g. a stormwater collection system). The control system 20 also includes a fluid reservoir 30 which is depicted as a simple tank 30. The tank 30 is arranged to receive fluid from an alternative fluid supply AS, such as a flow of rainwater off the user's home.

The fluid control system 20 includes an inlet valve 22 for providing recycled water to the tank 30 from the common supply CS, a fluid dump mechanism in the form of a dump valve 24 for dumping fluid from the tank 30 to the fluid collection system FC, detecting means 26 in the form of a pressure sensor for detecting the volume of the fluid in the tank 30 and control means in the form of a microprocessor 28 for controlling operation of the inlet valve 22 and the fluid dump valve 24 so that the fluid in the tank 30 can be maintained at a set level. A flow meter 29 is connected so as to measure flow into and out off the tank 30.

Although a pressure sensor 26 is used to detect the level of the fluid in the tank 30 other forms of detecting means are envisaged. For example, a series of pressure switches or float switches could be used to detect the fluid level in the tank 30 (albeit in discrete levels (i.e. over a range)). Another option would be an ultrasonic sensor where an ultrasonic sound signal is transmitted and a reflection from the water surface in the tank 30 is received and the level calculated from the time of flight. Dump valve 24 and inlet valve 22 may be solenoid or electric motor operated and are controlled by the microprocessor 28. A user input is provided to allow user adjustment of the desired water level (i.e. the set level) in the tank 30 and preferably also a manual override of the dump valve 24. Water level or volume readings of the tank 30 are shown on a digital display 28a of the microprocessor 28. The fluid control system 20 may be arranged for remote connection with an external receiver.

The tank 30 includes an outlet 31 to enable user usage of the contents of the tank 30.

Figure 1 A shows a fluid control system 20' similar to that shown in Figure 1 and which predominantly uses electronic components to perform the desired functions. This system 20' uses electric valves for both the inlet valve 22' and the dump valve 24', a pressure sensor 26' to detect the water level in the tank 30 and an electronic flow meter 29' to measure water flow in both directions. A microprocessor 28' with integral remote communication means is used to control the system 20'. A connection is provided between the microprocessor 28' and an external authority, through which bi-directional communication is allowed. This connection may be a wireless connection (as shown), phone line, power line or any other remote connection method. Data such as meter readings (water usage), water level in the tank 30, height setting of required water level etc is able to be sent from the system 20' to the external authority through this connection. The external authority is also able to control the operation of the system 20'. For example, the external authority is able to control the timing of the operation of the dump valve 24' to maximize storm water reclamation, or prevent the inlet valve 22' from filling the tank 30 when there is a high demand for water elsewhere.

Figure 2 shows a fluid control system 40 in accordance with a second embodiment of the invention that is hereafter referred to as a "mechanical design". The control system 40 uses a float 42 to operate a rotary inlet valve 44 and also includes a dump valve 46. The control system 40 includes a reservoir in the form of a tank 30. The tank 30 has an outlet 47 to enable user usage of the contents of the tank 30. The outlet 47 is located before a flow meter 48. The float 42 is located within a riser pipe 42a external to the tank 30. The float 42 is connected to the rotary inlet valve 44 which is arranged to rotate about its axis dependent upon the height of the float 42 within the riser tube 42a. The rotation of a disc 45 of the inlet valve 44 that is connected to the float 42 causes ports 45b in the housing to be opened and closed within the rotary inlet valve 44.

When the level of the fluid in the tank 30 is low, the disc 45 is rotated to a position where the ports 45a in the disc 45 open ports 45b in the housing of the inlet valve 44 to the connection to the common supply CS. This allows water from the common supply CS to flow into the tank 30. As the water level in the tank 30 rises, the float 42 also rises, causing the valve disc 45 to rotate thereby closing the connection to the common supply CS. When the level of fluid in the tank 30 is high, the disc 45 is rotated to a position where the dump outlet ports of the inlet valve 44 are opened. A secondary valve 46 is located downstream from the rotary inlet valve 44 to allow a user to dump water from the tank 30 to a fluid collection system FC when desired.

The user must open the dump valve 46 by pulling the actuator 54 upwardly. Dump valve 46 (dump valve) is held open by floatation (i.e. the valve 46 is made of material less dense than water) while water is flowing through it. When the water level in the tank 30 drains to the set level, the rotary inlet valve 44 will close the connection to the tank 30, preventing further water from flowing to the dump valve 46. Gravity then causes the dump valve 46 to return to the closed position, creating a seal against its seat and preventing water from flowing out until the user again raises the actuator 54 again. Water will only flow from the tank 30 with the water level high and dump valve 46 open.

Set water level adjustment (i.e. the amount of water normally to be stored in the tank 30) is provided by allowing the ports 45b in the housing of the rotary inlet valve 44 to be manually rotated with respect to the inlet valve disc 45, altering the water level at which the inlet ports 45a are opened. Figure 3 shows a fluid control system 60 in accordance with a third embodiment of the invention. This is an alternative simple "mechanical design". As shown in Figure 3 the control system 60 includes a reservoir (tank 30) arranged to receive inflow from an alternative supply AS (such as water runoff from a roof). The set level of the water in the tank 30 is set by the position of a ball float 62 within the tank 30. The ball float 62 is connected to a ball float valve 64 located at the top of the tank 30.

A fully mechanical bi-directional water meter 66 located in an outflow pipe 68 from the tank 30 is used to measure the water volumetric flow into the tank 30 from the common supply CS and out of the tank 30 to a fluid collection system FC. A user output port 69 is provided in the outflow pipe 68 adjacent the tank and before the water meter 66. The user output port 69 allows the user to take water from the tank 30 as needed.

The ball float valve 64 controls the connection of the tank 30 to the common supply CS such that when the float 62 goes below the set level of the tank 30 water from the common supply CS flows via pipe 71 , through the water meter 66 and into the tank 30. The flow of water into the tank 30 from the common supply CS is stopped when the float 62 returns to the set position.

A ball valve 72 is positioned after a raised pipe section 68a of the outflow pipe 68 to allow the user to dump water from the tank 30 when desired, without the water level within the tank 30 falling to below the level of the pipe 68.

The amount of water that the control system 60 will normally dump out of the tank 30 to the fluid collection system FC is set by the position of the outflow pipe 68. As the water level in the tank 30 drops to below the level of the outflow pipe 68, air is allowed to enter the system through a check valve 70 preventing water from being siphoned from the tank 30.

A mechanical timer tap may optionally be used to automatically close the ball valve 72 after a set time. Figures 4 to 10 illustrate a fluid control device 100 in accordance with a fourth embodiment of the invention. The fluid control device 100 is arranged to form a component of a fluid control system in accordance with an embodiment of the invention.

The fluid control device 100 includes a housing 101 with an inlet connection 102 for connection to a common supply CS, a tank connection 104 for connection to the outlet of a reservoir (e.g. a tank 30) and a dump outlet 106 for connection to a fluid collection system FC. The inlet connection 102 to the common supply is arranged to be opened and closed by an inlet valve 108. The dump outlet 106 to the fluid collection system FC is arranged to be opened and closed by a dump valve 1 10. Both the inlet valve 108 and dump valve 1 10 are normally operated by a diaphragm arrangement 1 12.

The fluid control device 100 is arranged so that when the inlet valve 108 is open, the dump valve 1 10 is closed so as to allow fluid from the common supply CS to flow through the tank connection 104 and into the tank 30. Furthermore, when the inlet valve 108 is closed and the liquid (hereafter referred to as water) in the tank 30 has reached a set level, it is possible for a user to dump water from the tank 30 by manually opening the dump valve 1 10 to allow water to flow out of the dump outlet 106 to the fluid collection system FC. Finally, if the water in the tank 30 goes below the set level, the dump valve 1 10 will be caused to close and the inlet valve 108 will be caused to open allowing water to flow from the common supply CS to the tank 30. The inlet valve 108 will remain open until the tank 30 is filled to the set level. The operation of the fluid control device 100 will be described in more detail subsequently.

The diaphragm arrangement 1 12 of the fluid control device 100 includes a diaphragm 1 14 located in an upper part of the housing 101 , a diaphragm support rod 1 16, a spring 1 18 and a spring guide 120. The spring 1 18 is mounted about the diaphragm support rod 1 16 and is compressed by contact with a height adjustor knob 122. The height adjustor knob 122 is arranged for threaded connection to the housing 101 .

The diaphragm 1 14 and the diaphragm support rod 1 16 are arranged such that the spring force applied by the spring 1 18 to the diaphragm support rod 1 16 is countered by the force of the water pressure acting on the diaphragm 1 14. When the water in the tank 30 drops below the level set by the user, the force applied by the spring 1 18 on the diaphragm 1 14 exceeds the force of the water pressure and thus the spring force drives the diaphragm support rod 1 16 downwardly.

The lower end of the diaphragm support rod 1 16 is connected to the dump valve 1 10. Typically, the dump valve 1 10 takes the form of a plunger that is arranged to seat and seal against a part of the housing 101 to close the dump outlet 106 when the support rod 1 16 is driven downwardly.

When the diaphragm support rod 1 16 is driven downwardly an inlet bell crank 224 pivotally mounted within the housing 101 is caused to open the inlet valve 108. Movement of the inlet bell crank 224 is best understood by comparing its position in Figures 4 and 5 and by close examination of Figure 8. In Figure 5 the inlet valve 108 is closed and the inlet bell crank 224 is not engaged by a protrusion 1 16a (see Figure 8) on the diaphragm support rod 1 16. When the diaphragm support rod 1 16 is driven downwardly, the protrusion 1 16a contacts a portion of the inlet bell crank 224 causing it to rotate in a clockwise direction. As it rotates it drives a valve stem 108a that pushes a plunger 108b of the inlet valve 108 away from a valve seat, thereby opening the inlet valve 108. The inlet valve 108 will remain open until the tank 30 is filled to the set level. At that time the diaphragm support rod 1 16 will return to its upward position under the action of the water pressure and the bias of the inlet valve spring 226 will shut inlet valve 108 causing the inlet bell crank 224 to return to the position shown in Figure 5. The height adjustor knob 122 is used to set the desired level of water in the tank 30. By lowering the height adjustor knob 122 the force applied by the spring 1 18 to the diaphragm 1 14 is increased. Therefore greater water pressure on the diaphragm 1 14 will be needed to counter the spring force. Accordingly, the set level in the tank 30 will be increased. By raising the height adjustor knob 122 the set level of the water in the tank 30 will be decreased.

It is envisaged that in most applications, the fluid control device 100 would be connected to a tank 30 that is also fed by an alternative supply AS. Typically, that alternative supply AS would be run off water from the user's house. However, the alternative supply AS may be a water supply from any external source.

When the tank 30 is filled to a level greater than the set level by input from the alternative supply AS, the water pressure on the diaphragm 1 14 will exceed the force applied by the spring 1 18. Accordingly, the diaphragm support rod 1 16 would normally be caused to move upwardly opening the dump valve1 10 and allowing water to flow to the fluid collection system FC. However, to allow the user to control dumping of water from the tank 30, the fluid control device 100 also includes a dump lever 150.

The dump lever 150 is arranged for pivotal connection (see pivot point 154) to the housing 101 . The dump lever 150 is normally latched downwardly (see Figures 4 and 6) to prevent upward movement of the diaphragm support rod 1 16 which would otherwise allow the dump valve 1 10 to open when water in the tank 30 was above the set level. As best seen in Figures 6 and 8, the dump lever 150 is generally U-shaped and has a cam 152 (see Figure 8) formed at each end adjacent to the pivot point 154. When the dump lever 150 is latched downwardly, the cams 152 contact the upper surface of the diaphragm support rod 1 16 thereby preventing upward movement of the diaphragm support rod 1 16 and hence upward movement of the dump valve 1 10. When the dump lever 150 is pivoted upwardly (see Figure 5) movement of the diaphragm support rod 1 16 is no longer prevented by contact with the cams 152 and thus moves upwardly under the action of the water pressure on the diaphragm 1 14. The dump valve 1 10 is then opened allowing water to flow out of the tank 30 and through the dump outlet 106 to the fluid collection system FC. The dump valve 1 10 will stay open until the force of the spring 1 18 is greater than the force applied by the water pressure on the diaphragm 1 14. At that stage the spring force will push the diaphragm support rod 1 16 downwardly to close the dump valve 1 10. The dump lever 150 will lower under gravity and/or a spring force so that the diaphragm support rod 1 16 and the cams 152 are returned into contact with the upper surface of the diaphragm support rod 1 16.

The dump lever 150 may also include a latch to enable the dump lever 150 to be retained in the upward (i.e. open) position. In this position water will be dumped automatically whenever the water level in the tank 30 rises above a set level.

Unless the dump lever 150 is latched in the upward position, the dump valve 1 10 will only open if the water in the tank 30 is above the set level.

The flow control device 100 also includes a flow meter 160 mounted within the housing 101 . The flow meter 160 is positioned adjacent to the tank connection 104 so that the flow of water into and out of the tank 30 can be measured. The provision of the flow meter 160 enables the user to be credited for water dumped from the tank 30 (i.e. water that flows back to an authority via the fluid collection system FC) and invoiced for any water actually consumed from the common supply CS.

In accordance with the illustrated embodiment (see Figure 9) the flow meter 160 is a turbine type and includes a turbine 160a and a magnet 160b fixed on a turbine 160a. The magnetic field of the magnet 160b is oriented perpendicularly to the turbine rotational axis such that it rotates with the turbine 160a. The rotating magnet 160b is sensed by two reed switches (not shown) mounted externally to the flow of water through the tank connection 104. The reed switches are mounted at a fixed angle to each other (angle in plane perpendicular to rotational axis). This enables the direction of the rotation of the turbine 160a to be detected and hence water flow direction through the flow meter 160 to be determined through associated electronics including a microprocessor (not shown). Those water flow recordings are stored by the microprocessor for later use by a water authority.

In accordance with this embodiment, the flow meter readings are shown on an LCD display 170 (see Figure 10) attached to the flow control device 100. The LCD display is normally set to be visible only upon opening of a cover 172 over the LCD display 170. The LCD display is switched off when the cover 172 is down to save power. The LCD display 170 is also turned off if the cover 172 has been left open for a set period of time (e.g. 30 seconds). The microprocessor enters a sleep mode to conserve power when no inputs are sensed from the flow meter 160 or cover 172.

The measured and recorded volumetric flow rate readings may be submitted by the user to a water authority or some other authority. To ensure correct readings are submitted a verification code is generated through the microprocessor associated with the flow meter 160. This verification code is additional to the "in" and "out" water flow readings provided by the microprocessor. This verification code is a unique code generated using an algorithm based upon the "in" and "out" water values. When the user submits their water "in" and "out" readings to the water authority, they are required to also submit the verification code (i.e. a third value). The water authority is able to use the verification code to verify that the first two values are correct. In this manner, the costs of meter reading are greatly reduced, while also promoting water usage awareness. It is desirable to prevent low flow rates through the flow meter 160 that may not be registered. Such low flow rates are prevented by the inclusion of a hysteresis mechanism on the diaphragm support rod 1 16.

Figure 7 illustrates conceptually a hysteresis mechanism for preventing low flow rates through the flow meter 160 and Figure 9 illustrates that mechanism as within the fluid control device 100. As illustrated, the diaphragm support rod 1 16 has raised protrusions 1 16b on its periphery above the protrusion 1 16a (discussed in relation to the inlet bell crank 224). Rollers 180 are constrained to move in the horizontal plane with force applied to them by springs 182. The rollers 180 are thus forced to follow the shape of the periphery of the diaphragm support rod 1 16. As the pressure force on the diaphragm 1 14 moves away from equilibrium (i.e. when the pressure force on the diaphragm 1 14 due to water pressure is equal to the spring force from spring 1 18), the rollers 180 are forced to move out over the protrusions 1 16b on the diaphragm support rod 1 16. This produces an additional force opposing the motion of the diaphragm support rod 1 16, preventing the inlet or dump valves 108, 1 10 from opening until a higher force difference between the water pressure on the diaphragm 1 14 and spring force on the diaphragm 1 14 is reached.

This mechanism causes a hysteresis effect on the diaphragm support rod 1 16 and hence the opening and closing of the inlet and dump valves 108, 1 10. Rather than gradually opening and allowing only a small flow rate through them, the valves 108, 1 10 will 'snap' open as the rollers 180 move over the protrusions 1 16b on the diaphragm support rod 1 16. The result of this is that the water level in the tank 30 must fall to a distance below the set level before the inlet valve 108 will open and must be a distance above the set level before the dump valve 1 10 can be opened. This ensures that the valves 108, 1 10 are either fully open or closed at all times.

As will be appreciated from the above description of various preferred embodiments, the invention in its different embodiments allows low pressure liquid, such as water that is supplied through a small diameter pipe network, to be used to maintain the set water level in a tank located at a user's property. The water stored in the tank can then be used at the user's property with a standard pressure pump to provide the required water pressure.

Different embodiments of the invention allow the user or an authorised authority to selectively release an alternative supply such as rainwater that flows into the user's tank into the fluid collection system FC when desired. This allows the tank volume above the set water level to be used as a storage buffer whilst it is raining, with the user (or an authorised authority) able to release the excess stored water to a fluid collection system FC at a later time when the processing systems are able to process the water without it being wasted and flowing out to sea. Furthermore, an authorised authority may also be able to control operation of the inlet valve at the user's property so as to open the inlet valve under certain conditions (i.e. in addition to when additional water is required to take the water level to the set level). The authorised authority may want to open the inlet valve when, for example, the pressure in the reticulated water system reaches a particular level at certain times of the day. The authority may also want to control operation of the inlet valve (i.e. close the inlet valve) at certain times of the day to ensure adequate water supply to parks and gardens watered by the authority or another entity (typically a council) through the reticulated water system. Without control of the inlet valves at each household or property connected to the reticulated system, there may be times when there was otherwise an inadequate supply for council use due to household user draw.

The authorised authority may also be able to control operation of the dump mechanism to dump fluid in the reservoir irrespective of the set level of the tank. This may be desirable if the authority wants to empty the tank for cleaning or inspection.

The embodiments have been described by way of example only and modifications within the spirit and scope of the invention are envisaged. Future patent applications may be filed in Australia or overseas on the basis of or claiming priority from the present application. It is to be understood that the following provisional claims are provided by way of example only, and are not intended to limit the scope of what may be claimed in any such future applications. Features may be added to or omitted from the provisional claims at a later date so as to further define or re-define the invention or inventions.