AU8933398A - Water main isolating device - Google Patents

Description

1100 W1! RezUlaICon 1.2

AUSTRALIA

Patents Act 1990 COMRVPLETE

SPECIFICATION

FOR A STANDARD PATENT

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ORIGINAL

Name of Applicant: Actual Inventor: Address for service YAJRtA VALLEY WATER LTD Grant Coiling in Australia: CARTER SMITH BEADLE 2 Railway Parade Camberwell Victoria 3124 Australia rInvention Title: WATER MLAIN ISOLATING DEVICE Details of Associated Provisional Application: PP0130 filed 31 October 1997 The followaing statement is a full description of this invention, including the best method of performng it knowi to us 2 -2- WATER MAIN ISOLATING

DEVICE

INTRODUCTION TO INVENTION This invention relates to the maintenance of town supply water mains pipes and in particular, to a device for isolating a section of a mains water supply to assist such maintenance work.

BACKGROUND TO INVENTION Town center mains water is supplied to households and light industry from reservoirs via pumps and a network of generally underground piping. The piping is generally configured as a branching network of pipes of diminishing dimensions ending with street mains water pipes of about 100 mm diameter running along town streets past households and into which a plurality of individual households can tap.

At the street level, the mains water pipes are provided with closable gates at regular intervals every kilometre or so to allow sections of the supply to be isolated for maintenance. However, the number of gates provided only allows isolation of a relatively large area which may affect 50 or so households. Accordingly, maintenance of a water mains pipe can often potentially inconvenience a large ii number of households for the duration of such maintenance.

The mains water supply piping whilst principally provided for the supply of household water also functions for emergency water supply by way of fire hydrants or fire plugs, many of which are fitted at intervals along the street front and allow emergency access to mains pressure water by fire fighters. Fire hydrants are generally installed at regular and frequent intervals along the mains water supply piping such that a plurality of fire hydrant access points exist between any two or more isolation gates in a mains water system.

25 It would be very desirable if the fire hydrant access points could be utilized to shut off the mains water supply by acting as temporary isolation gates; particularly as the frequency of the hydrants would allow a very small number of k households to be affected by mains water pipe maintenance if such hydrant points j could be used to isolate a section of mains water pipes.

i i -3 OBJECT AND STATEMENT OF INVENTION One object of the invention is to provide a retrofittable device capable of cooperating with a mains water supply fire hydrant or fire plug to allow closure of the mains water pipe in the vicinity of the hydrant.

Accordingly, in one aspect, the invention provides a device for occluding a mains water supply pipe including an elongate shaft and a plug means fitted to a first end of said shaft wherein said shaft is adapted for insertion into the stack of a fire hydrant or fire plug fitted to said mains water supply pipe such that said first end thereof can be positioned proximate to said mains water supply pipe and said plug can be positioned to occlude said mains water pipe.

In another aspect, the invention provides a device for occluding a mains water supply pipe including an elongate shaft and an expandable plug means fitted to a first end of said shaft wherein said shaft is adapted for insertion into the stack of a fire hydrant fitted to said mains water supply pipe and said plug is expandable and convertible between a first contracted state adapted for insertion into and removal from said mains water pipe and a second expanded state adapted to sealably engage I a portion of said mains water pipe and thereby occlude said pipe.

The expandable plug is preferably a pneumatically actuated bladder. The elongate shaft may be hollow and incorporate a pneumatic hose for remotely 20 actuating the expandable plug. The pneumatic hose may be fitted with a valve to control the state of expansion or contraction of the plug. The contracted plug may be housed in an opening on the side of said shaft at or near said first end such that the contracted plug and shaft assembly can be readily inserted into the flange and 1 down the stack of a fire hydrant so as to allow access to said mains water pipe supply. i In another embodiment, the invention provides a device for occluding a mains water supply pipe including a first outer hollow elongate shaft or sleeve adapted for insertion into and traversal of the length of the stack of a fire hydrant or fire plug and a second elongate shaft adapted for insertion into said first hollow shaft wherein said second elongate shaft has an expandable plug fitted to a first end thereof with MW:Pf;6S,4 CAj I C15 ba 199S i -4the expandable plug convertible between a first contracted state and a second expanded state such that the second shaft and plug assembly is readily inserted into said first shaft and upon expansion said plug migrates into said mains pipe and occludes same.

The expandable plug means is preferably inserted into the mains water supply pipe upstream of the flow direction of water through said pipe.

The expandable plug means can be any material adapted to sealably engage the mains water pipe but is preferably a durable rubber based material able to maintain a pressure of at least 120 psi.

In another aspect, the plug is made of resilient material shaped to allow movement from a first position which does not occlude the mains water pipe to a second position sealably engaging a portion of the mains pipe and thereby occluding said pipe. The shape is preferably frustro conical or spheroid.

The elongate shaft is preferably rigid and of sufficient length to fully traverse the length of a hydrant stack resting on the lower portion of a mains water pipe and projecting out of said hydrant stack above ground and adapted for anchoring to the flange of said hydrant.

Figure 1 shows a cross section view of the device fitted to a fire plug.

Figure 2 shows a cross section end view of the device fitted to a fire plug.

Figure 3 shows a cross section end view of the device fitted to a fire lug.

Figure 4 shows details of the plug means.

"'"'DETAILED DESCRIPTION OF THE INVENTION While the device of the invention can take many different forms, a particularly preferred aspect and embodiment of the invention is detailed with reference to Figure 1 where the invention comprises a device adapted for use in conjunction with mains water supply fire hydrants, being aboveground units, or mains water supply fire plugs, being inground units, both of which are directly connected to the mains water supply pipes running underground. The device MAW P?:2SS824LCAP I r oa 199S 8~-RI1I1~ UL~i~Y~ -~C includes an elongate shaft 1 which is provided in a suitable length and outside diameter to be fitted down the internal stack 2 of a fire hydrant 3. In application the fire hydrant or fire plug would be accessed by a worker who after ensuring that the main shut off gates of the mains water supply pipe 4 have been closed would remove the hydrant head 5 of a suitably positioned fire hydrant upstream of the point in the water pipe 4 requiring maintenance. Once the hydrant head 5 has been removed, the upper most flange of the hydrant 6 will be exposed along with the internal construction of the main hydrant stack 2. The hydrant stack 2 passes down into the ground 7 and meets with the water pipe 4 at a Tee junction 8. The shaft 1 is made of a suitable length such that it can be inserted down the hydrant stack 2 and once it abuts the bottom of the Tee 8, a portion of the shaft 1 is left protruding above the ground. The shaft 1 is adapted for secure fitting to the flange region 6 of the hydrant stack 2 in order to provide a rigid and secure access means to the water pipe 4 via the fire hydrant 3. Associated with the shaft I is a plug means 9 I 15 which is fitted to a first end 10 of the shaft 1. The plug means is formed as a compliant inflatable rubberised bladder which can be either expanded by providing air pressure to the inside of the bladder so as to adopt a second expanded state or alternatively, the plug means can be deflated by releasing the pressure in the bladder thereby effecting the contraction of the bladder to a first state. In this manner, the expandable plug means is capable of being converted from a first contracted state to a second expanded state by application or removal of pneumatic pressure supplied via an air hose 11 which passes from the inflatable bladder 9 up the internal channel of the shaft I to the exterior terminating in a valve 12. The ability of the plug means to be inflated or deflated, ensures that the device can be easily fitted down the hydrant stack 2 with the plug means deflated. In this manner, the plug means is of smaller dimensions to the internal diameter of the hydrant stack and can be *s easily passed down the hydrant stack and negotiated such that it can be positioned facing the flow direction of water passing through to water pipe 4 and when the plug means is inflated by way of pneumatic pressure applied via the air hose 11, the plug means will adopt its second expanded state thereby expanding within the confines MAW.PP268S.CAP 15 Oaobc 1l8 all; i

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-6f a water pipe 4 and effectively occluding the water pipe 4 and preventing passage of water passing from the upstream to the downstream side of the Tee junction.

Once the pipe has been occluded, the main shut off gates can be opened leaving only a small section of mains water pipe between hydrants isolated and without water.

In this manner, any one of the available fire hydrants can be used in conjunction with the device of the invention to occlude or seal off the mains water supply at any available hydrant access points. Once work has been completed on the downstream region of the water pipe 4, the main shut off gates are again closed, the valve 12 can be opened, releasing the air pressure on the expandable plug and thereby allowing 0 the expandable plugto contract and facilitate removal of the whole device by pulling the shall I from the hydrant stack 2. Once the device has been removed from the fire hydrant, the hydrant head can be replaced, the main shut off gates opened thereby returning the mains water pipe system to normal operation.

Figure 2 shows a similar view to that provided in Figure 1, except an end view of the water pipe 4 is shown detailing the complete occlusion of the whole diameter of the water pipe 4 by the plug means 9.

Another embodiment of the invention is shown in Figure 3 where the shaft 1 is provided as a secondary tube that fits conveniently within a primary insertion shaft 11. The shaft i incorporates all the features of the previous embodiment however, the addition of the insertion shaft 11 can be of assistance in ensuring the smooth traversal of the shaft 1 and its plug means 9 down the length of the hydrant stack 2.

Figure 4 provides various embodiments of the plug means with Figure 4A and Figure 4B showing plug means in the form of a solid rubber plug 9 which can be moved from a first position (Figure 4a) within the confines of the shaft 1 which does hydrant stack 2. Figure 4b shows the plug in the second position where it has been moved outside the shaft 1 and moved into the water pipe 4 in a manner to occlude the movement of water down the pipe. Figure 4C shows another embodiment of the S1 Oobo 199 M.W.PP.S26S 2 I CAP 4 ;1 i: i 7 expandable plug means in the form of an inflatable bladder which can be converted from a first contracted state with the bladder uninflated shown in Figure 4c to a second expanded state shown in Figure 4D where the bladder has been pumped up by way of pneumatic or other pressure to a pressure in the order of 120 psi which is sufficient for the bladder to expand out against the inside of the water pipe 4 and effectively occlude the water pipe and prevent the passage of water across the plug.

The plug means part of the invention is preferably provided by way of a durable rubberised material which is sufficiently durable to avoid being damaged during insertion and removal from the Tee joints which may often include rough areas that can damage the bladder.

The various embodiments of the invention provide for the first time a simplified and reliable device which can be used in conjunction with accessories to a town water supply pipe system in order to access the mains water pipes and effectively occlude or shut off those pipes at very regular intervals corresponding to the available fire hydrants. Whilst the installation of the device of the invention does require the temporary shutting off of the main pipe gates, once the device of the invention has been installed in one or a plurality of relevant fire hydrants, the main water pipe gates canbe re-opened thereby allowing only a section between the two relevant fire hydrants to be isolated and deprived of water such that maintenance can be carried out in a highly specific region of the water mains pipes and thereby inconvenience a minimum number of residence.

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Claims (9)

1. A device for occluding a mains water supply pipe said device including an elongate shaft and a plug means associated with a first end of said shaft wherein said shaft is adapted for insertion into the stack of a fire hydrant or fire plug fitted to said mains water supply pipe such that said first end thereof can be positioned proximate to said mains water supply pipe and said plug can be positioned to occlude said mains water pipe.

2. A device according to claim 1 wherein said plug means is expandable from a first contracted state adapted for ready insertion into and removal from said mains water pipe to a second expanded state adapted to sealably engage a portion of said mains water pipe and thereby occlude said pipe.

3. A device according to claim 2 wherein said plug means is a pneumatically actuated bladder.

4. A device according to claim 3 wherein said shaft is hollow and bladder is fitted and pneumatically connected to said hollow shaft so as to allow said bladder to be remotely inflated or deflated to achieve said expanded or contracted state. A device according to claim 3 wherein said shaft is hollow and open ended and said bladder is loosely positioned toward the first end of said hollow shaft and S. provided with a pneumatic conduit to allow said bladder to be remotely inflated and 'deflated from a second end of said shaft such that upon inflation said bladder adopts a second expanded state beyond the open end of said shaft so as to occlude said mains pipe.

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6. A device according to claim IN-herein said plugi hpdt lo~ Secofd Pslti; sebi egaging a portion of said mains wvater Pipe and thereby Oc een t sa ni ap i rsoiine.l d e o cl d ad an ae i et

7- A device accord in to clai 6 h ri ad pu s fut Cnical shaped.

8 Adeieacring to claim 6 wherein said plua srs

9. A device accord ing to any one of claims I to 8 fu~rther including an outer hollowv elongate shaft adapted for in1sertion i'to and traversal of the length of the stack of a fire hydrant or fire Plug wherein the device of claim I to S is adapted for insert-'on into said outer hollow shaft so as to ensure ready traversal of said stack by said device. 1. A device according to any One of claims Ito 9 substantially, as -hereIII, fore described. DATED: 15 October 1998 CARTER SMITH B3EADLE Patent Attorneys for the Applicant. YMZR VALLEY WATER LTD