WO1995005507A1

WO1995005507A1 - A fluid release means

Info

Publication number: WO1995005507A1
Application number: PCT/AU1994/000478
Authority: WO
Inventors: Christopher Roy Harkness
Original assignee: Riego Pty. Ltd.
Priority date: 1993-08-16
Filing date: 1994-08-16
Publication date: 1995-02-23

Abstract

At dead ends in a water reticulation system debris and dirt may accumulate. The invention uses a diaphragm valve (16) to automatically release water periodically from a dead end so as to flush out dirt, etc. A by-pass line (29, 32) is provided around valve (16). This line passes through an on-off, battery powered, timer valve (18). When the timer valve is opened, fluid flows through the by-pass line to downstream of the diaphragm valve which results in a pressure drop above the diaphragm and the water pressure upstream opens the valve (16). A pressure reducing valve (30) in the by-pass line allows timer valve (18) and check valves (20) to be of low pressure type. A needle valve or orifice plate prevents potential damage due to a rapid build up of pressure upstream of valve (16) when the latter closes.

Description

A FLUID RELEASE MEANS Technical Field

The present invention relates to a fluid release means for use in a fluid reticulation system for periodically flushing fluid from a dead end of a fluid conduit. In particular, although not exclusively, the invention relates to a water release valve in a water reticulation system whereby water may be released periodically from a dead end in a water mains conduit. The invention however, is not limited to applications in water reticulation systems and may be used in sewerage systems, gas systems or any other fluid system where it may be desirable to flush a portion of the system. Background Art

In an urban or suburban water reticulation system, water is supplied to end users from the water supply facility via water mains pipes which branch into secondary water pipes and so on until the system reaches each of the end users. In most parts of the system, the flow of water itself is sufficient to prevent the accumulation of any debris in the system. Thus the system is self-flushing in most parts. However, problems occur when a water pipe terminates i.e. reaches a 'dead end¹ portion as this provides an ideal location for debris and dirt to accumulate, possibly leading to blockage of the pipe. Further problems are encountered by users of the system connected adjacent the dead end portion as the accumulated debris may be drawn into and pollute the users, water supply. A cul-de-sac is a typical example of this situation and users at the end of the cul-de-sac can experience a polluted water supply as a result.

It has therefore been a practice to provide any such dead end portions with a valve whereby the water and accumulated debris may be flushed out. This involves a very labour intensive operation requiring a water supply worker to travel to the valve, manually operate the valve, wait until sufficient water has flushed through the dead end portion and then close the valve. Where there are many such valves in a system, the labour effort required is multiplied, especially where the valves are some distance apart.

It is therefore an object of the present invention to provide a fluid release means which overcomes the problem of debris accumulation in a dead end portion of a fluid conduit in a less labour intensive manner. Disclosure of Invention

In accordance with a first aspect of the present invention, there is disclosed a fluid release means for location at or adjacent an end of a fluid conduit for periodically releasing fluid from said conduit, said fluid release means comprising: a fluid release valve for releasing fluid from said conduit; a fluid by-pass conduit, passing from upstream of the fluid release valve to downstream thereof; a valve actuating means responsive to a change in pressure differential between the by-pass conduit and the fluid conduit upstream of the fluid release valve; a timer means for periodically creating a change in said pressure differential thereby controlling the valve actuating means and the periodic release of fluid. In a preferred form of the invention, the valve is a diaphragm valve, fluid from the by-pass conduit being in communication with a diaphragm such that flow of fluid through the by-pass conduit induces a change in pressure on the diaphragm of the diaphragm valve, thereby actuating the diaphragm valve. The timer means may also be located in the by-pass conduit to control the flow of fluid in the conduit and thereby control the diaphragm valve.

The fluid release means may be further provided with a pressure reduction means, a practical consideration where water is to be released from a water mains into a street. In the preferred form of the invention, a pilot valve may serve as a pressure reduction means. Preferably, the pressure reducing pilot valve is located in the by-pass conduit upstream of the timer means.

The diaphragm valve may also be provided with means to slow valve closure to prevent damage to the valve and conduits to which the release means is connected. Preferably a flow control means is provided in the by-pass conduit upstream of the diaphragm. This controls the flow of fluid through the by-pass conduit to the diaphragm thereby controlling the speed at which the diaphragm deflects and the valve closes. In one preferred form of the invention, the flow control means is a needle valve which may be adjusted to adjust valve closure speed to an optimum speed. In an alternative form, the flow control means is in the form of an orifice plate which provides fixed control of the flow therethrough. If it is desired to change the flow rate, the orifice plate may be substituted for another which provides a different flow rate.

The timer means may toggle the flow in the by-pass conduit to be either flowing or not flowing. The timer means may control the period for which the fluid flows and/or the frequency of the flow periods. Preferably, one or both of these operational parameters may be adjusted by resetting the timer means. The timer means may have a mechanical timing mechanism or an electric timing means. In a most preferred form, the timer means is battery operated.

The fluid release means may also be provided with backflow prevention means. This may take the form of one or more check valves. In a preferred form of the invention, a number of branched conduits are provided downstream of the release valve, each branch being provided with a check valve. In a most preferred form, there are two branches each having a check valve.

The fluid release means may be mounted within a housing. It is preferred that the release means is preassembled in the housing prior to being taken to the site for installation. A mains coupling may be provided externally of the housing. At the preassembly stage, any of the components of the release means e.g. pilot valve, needle valve can be preset. On installation, the housing may be buried in the ground. In one form of the invention, the timer means is not located within the housing so that any one of the settings on the timer can be adjusted if necessary.

In accordance with a second aspect of the present invention, there is disclosed a fluid reticulation system having one or more fluid conduits which terminate in a dead-end, said system having one or more fluid release means located at or adjacent a respective dead-end wherein each said fluid release means has a timer means for controlling periodic release of fluid. Brief Description of the Drawings In order that the invention may be more fully understood, some embodiments of the invention will now be described with reference to the figures in which: Fig. 1 is a schematic view of a fluid release in accordance with a first preferred embodiment;

Fig. 2 is a plan view of the fluid release in accordance with the first preferred embodiment; Fig. 3 is an elevation view of the fluid release of Fig. 2;

Fig. 4 is a plan view of a fluid release in accordance with a second preferred embodiment; and

Fig. 5 is an elevational view of the fluid release of Fig 4. Modes for Carrying Out the Invention The schematic view of Fig. 1 illustrates the fluid release 10 comprising an inlet port 12, an outlet port 14 and release valve 16 controlled by a timer 18. The embodiment shown is specifically adapted to be used at the dead-end of a water pipe in an urban or suburban water reticulation system. A suitable timer is a GALCON (T.M.) timer as manufactured by Galcon Irrigation Control Equipment, Israel. Downstream of the release valve 16 are a pair of branch lines 18, each branch line 18 having a check valve 20 to prevent backflow. The use of two branch lines 18 and two check valves 20 is an economic consideration, the cost of a single check valve being prohibitive in this application. It will be appreciated that any number of branch lines, each with a respective check valve may be incorporated into the fluid release means depending on the flow requirements of the fluid release 10.

Fig. 2 shows in more detail the components mentioned above. The components are mounted by brackets 21 within a plastic casing 22 having a plastic cover 23. The inlet port 12 and the outlet port 14 each extend beyond the confines of the casing 22 and are each provided with a threaded portion. The ports 12, 14 are bracketed to the casing 22 to eliminate relative movement between the components of the fluid release 10 and the casing. The release valve 16 is in the form of a diaphragm valve such as that manufactured by Australian Valve Industries. The diaphragm valve 16 is of the type in which a pressure drop in fluid acting on the diaphragm allows the valve to open.

A tee connection 28 is screwed into the top of the diaphragm valve 16 connecting the diaphragm valve 16 and a pressure reducing pilot valve 30 mounted above the diaphragm valve 16. The tee connection 28 is also connected via a first hydraulic line 29 to upstream of the diaphragm valve 16. A needle valve 31 is provided in the first hydraulic line, the use of which will be explained later. A second hydraulic line 32 from the pilot valve 30 to downstream of the diaphragm valve 16 completes a by-pass line around the diaphragm valve 16. The second hydraulic line 32 passes through the timer valve 18 which determines whether flow will occur through the by-pass line. The pressure reducing pilot valve 30 reduces the pressure to the components downstream thereof including the timer valve 18 and the check valves 20. Therefore, these components will be subjected to lower pressures than the diaphragm valve and can be selected accordingly.

The timer valve 18 is a battery operated on/off valve which allows fluid to flow for certain periods of time and preventing flow for the remainder of the time. The timer valve 18 allows for these time periods to be adjusted. The flow time may be adjusted in increments of minutes or hours and the frequency thereof may be adjusted between 45 minutes and 21 days. The timer valve 18 is located externally of the casing 22 as shown so that it may be easily serviced eg. change batteries, and to avoid moisture problems. Preferably, the timer is mounted in a box, with the batteries coated with a moisture resistant solution such as a moisture resistant gel. A polyethylene tube 34 is used to carry the second hydraulic line 32 to and from the timer 18. The timer 18 may be mounted up an electricity pole, within private property or in a water meter box.

Preferably, the fluid release 10 is preassembled in the casing 22 prior to transportation to the installation site. During this preassembly stage, the operating parameters of any of the valve components (16, 30, 31) or the timer 18 may be preset.

In use, when the timer valve 18 is "off", no fluid flows through the by-pass line and there being no pressure differential across the diaphragm, the diaphragm valve 16 remains closed. When the timer valve 18 switches to "on", fluid flows through the by-pass line to downstream of the diaphragm valve. This results in a pressure drop above the diaphragm and the force of the water upstream opens the diaphragm valve 16. The valve 16 remains open throughout the running period of the timer valve 18. The running period of the timer valve is set according to the amount of water required to be flushed. When the timer valve 18 has completed its running period, it switches to "off and the pressure starts to build up above the diaphragm. This pressure build-up however, is controlled by the needle valve 31 which restricts fluid flow through the first hydraulic line 29. As pressure build-up above the diaphragm is controlled, the valve 16 will close slowly reducing shock to any components upstream of the diaphragm valve 16.

Figs. 4 and 5 illustrate an alternative embodiment of the present invention and like numerals represent like parts. The embodiment of Figs. 4 and 5 differs in that a needle valve 31 is not used to control the flow in the first hydraulic line 29. Instead, an orifice plate 36 is inserted into the end of the tee connection 28 which is connected to the first hydraulic line 29. The orifice plate 36 may be substituted for another orifice plate if a different flow rate therethrough is desired. It will also be noted that the embodiment of Figs. 4 and 5 differs in that the timer valve 18 is located inside the casing 22, thereby resulting in a more compact unit.

The foregoing describes only some embodiments of the present invention and modifications, obvious to those skilled in the art can be made thereto without departing from the scope of the present invention. For example, the fluid release may not be limited to use at the end of a mains pipe and could conceivably be used in household or commercial applications.

Claims

CLAIMS:

1. A fluid release means for location at or adjacent an end of a fluid conduit for periodically releasing fluid from said conduit, said fluid release means comprising: a fluid release valve for releasing fluid from said conduit; a fluid by-pass conduit, passing from upstream of the fluid release valve to downstream thereof; a valve actuating means responsive to a change in pressure differential between the by-pass conduit and the fluid conduit upstream of the fluid release valve. a timer means for creating periodically a change in said pressure differential thereby controlling the valve actuating means and the periodic release of fluid.

2. The fluid release means as claimed in Claim 1 wherein the valve actuating means is subjected to the fluid pressure in the by-pass conduit.

3. The fluid release means as claimed in Claim 2 wherein the timer means is a time controlled on/off valve located in the by-pass conduit.

4. The fluid release means as claimed in Claim 1 wherein the fluid release valve and the actuating means are combined in the form of a diaphragm valve having a diaphragm which is subjected to the pressure in the by-pass conduit.

5. The fluid release means as claimed in Claim 1 further including a flow control means in the by-pass line to slow closing of the release valve.

6. The fluid release means as claimed in Claim 5 wherein the flow control means is an orifice plate.

7. A fluid release means as claimed in Claim 4 further comprising a pressure reduction means located in the by-pass conduit upstream of the timer means.

8. A fluid reticulation system having one or more fluid conduits which terminate in a dead-end, said system having one or more fluid release means located at or adjacent a respective dead-end wherein each said fluid release means has a timer means for controlling periodic release of fluid.

9. The fluid reticulation system as claimed in Claim 8 wherein the or each fluid release means includes a diaphragm valve and a by-pass conduit said diaphragm valve including a diaphragm subjected to fluid pressure in the by-pass conduit such that a change in pressure differential between the by-pass conduit and the conduit upstream of the valve effects opening and closing of the valve.

10. The fluid reticulation system as claimed in Claim 9 wherein the timer means creates the change in pressure differential thereby controlling opening and closing of the valve.