AU2008200314A1 - Valve Control System - Google Patents

Description

06 Feb 08 02:25p Sigra Pt j Ltd 61 7 3216 6988 p.2 001 0 0 VALVE CONTROL SYSTEM BACKGROUND OF THE INVENTION There is a need to be able to supply water form tank storage to a (building's) reticulation system. It is S 5 advantageous if this system will operate with a mains water supply to reticulation system also. To supply this need a valve is required that will enable pressurised tank water to be supplied to the system when this is available and to be able to switch across to mains supply when the tank water -i ceases to be available.

00 O This change over should be automatically achieved. This patent describes such a valve.

l 010 SUMMARY OF THE INVENTION The invention permits the use of water stored in some reservoir (tank) to be supplied to a building's reticulation system when t is available and to automatically switch across to mains water supply when the tank runs dry. To achieve this, the tank water supply needs to be detected by some level sensor such as a float switch or pressure transducer. A controller of some form then turns on a pump which pressurises the water supply from the tank through a non return valve to the building's reticulation system. Normally a hydraulic accumulator will be incorporated into the reticulation system to provide pressurised storage capacity. In addition to the pressurised tank supply the building has supplied to it a mains water supply which is to be used when the tank water becomes unavailable. The main object of this invention is the valve and valve control which connects either the pressurised tank water supply, or in its absence, the mains water supply to the building's reticulation system. To achieve this, a three port valve may be used which is preferably a three port shuttle valve or may also be any other three port valve such as a ball valve. This valve is fitted with a control system such that the valve remains in the position of conducting water from the pressurised tank supply to the reticulation system when the tank supply system is pressurised. When there is no pressure in the tank supply system the valve automatically switches to supply water from the mains to the reticulation system.

This automatic switch is achieved by having a spring loaded hydraulic actuator that moves the valve to a position that accepts water from the pressurised tank water supply and delivers it to the buildings reticulation system when there is water pressure supplied by the pressurised system.

When the tank water supply ceases to be pressurised because the pump is off, the valve changes position to connect the mains water supply to the building reticulation system. This change of position is achieved by spring actuation. To achieve this, the hydraulic actuator needs to be bled of fluid so that the spring may change its position.

To bleed the hydraulic actuator so that the spring will operate it, a bleed valve is required.

This bleed valve should be closed when the system is pressurised so that water pressure may COMS ID No: ARCS-178151 Received by IP Australia: Time 14:59 Date 2008-02-06 06 Feb 0@ 02:25p Sigra Pt d Ltd 06 eb 8 0: 25 Sira t~ td61 7 3216 6988 p.

3 0 operate on the hydraulic actuator. When the system looses pressure the valve opens and bleeds water out of the actuator to permit it to change position.

DESCRIPTION OF DRAWINGS FIGURE 1 Figure 1 shows a water tank which feeds water via conduit (17) to pump Pump (4) en delivers the water via non return valve to Tee and on to the three port valve (10) via port O Also connected to the non return valve outlet circuit is a hydraulic accumulator This hydraulic accumulator damps pressure fluctuations in the system and maintains pressure under conditions 00 45 of low flow. Also connected to the three port valve (10) via port is the mains water supply (11).

O Sensor preferably a pressure transducer, senses water pressure in the tank and delivers this signal to the controller which is shown here to be mains electricity powered via cable (14).

The controller also receives a signal on pressure downstream of the pump through Sensor (18) low pressure at the sensor (18) the pump operates to raise the pressure to some preset valve. The pressure at the Tee should be enough to operate a hydraulic control circuit (13) which enable the three port valve (10) to be switched to deliver water from the tank to the outlet of the three port valve (12) and the buildings reticulation system. When the pump ceases to operate because there is insufficient water in the tank as detected by sensor or the mains power of the system fails the pressure declines water from the mains source (11) to the outlet The details of the control circuit are shown in Figure FIGURE 2 Figure 2 shows a three port shuttle valve and its control circuit. The valve consists of a body with two inlet ports. Port (22) takes water from a pressurised source (31) which would normally be the tank and pump circuit described in the previous drawing. Port (23) takes water from another source which would normally be the mains water supply. Port (24) is the outlet port. The shuttle (21) redirects water form either inlet port to the outlet port. Irn the drawing the shuttle (21) is shown in a left position to hydraulically connect inlet port (23) with the outlet port It is driven to this position by spring (28) which is enclosed in extension tube (26) fitted with bleed The shuttle is fitted with hydraulic seals (42 to When pressure from source (31) becomes available it is connected to inlet port (22) of the valve via a tee (30) and nipple Control conduit (33) is connected to the tee (30) via bush (32) and conveys fluid pressure to the end of the shuttle (21) via conduit (34) connected to shuttle body end cap (25) and to the control valve (37) via conduits (35) and The pressure in this circuit closes the valve (37) and drives the shuttle (21) to the right, thus connecting inlet port (22) to outlet port Water may now be delivered from the tank circuit to the building's reticulation system.

Valve (37) is designed to be closed when the system is pressurised and to permit bleed off of fluid via port (40) when it is not pressurised. The valve in this embodiment consists of a body (37) which holds a needle (39) which is actuated by a diaphragm (38) which senses the pressure above it compared to that below it. This closes the needle (39) into port (41) preventing fluid loss via conduit COMS ID No: ARCS-i 781 51 Received by IP Australia: Time 14:59 Date 2008-02-06 06 Feb 03 02:25p Sira Ptyj Ltd 61 7 3216 6988 p.4 0 3 0 Thus the system may preventing fluid loss via conduit Thus the system may build up Spressure. When pressure falls away the needle is not build up pressure. When pressure falls away \the needle is not held against its seat and fluid may leak off via conduit (36) held against its seat and 0 fluid may leak off via conduit (36) and port (41) to discharge form port Thus the shuttle (21) may travel to the left driven by spring It should be appreciated that the exact form of the control valve may be changed. A similar result could have been achieved using a piston operated needle rather than one controlled by a diaphragm.

0 0 0 0 ci COMS ID No: ARCS-178151 Received by IP Australia: Time 14:59 Date 2008-02-06