WO2001069120A1

WO2001069120A1 - Improved pipeline isolating device

Info

Publication number: WO2001069120A1
Application number: PCT/AU2001/000279
Authority: WO
Inventors: Richard Burlock; Craig Evans
Original assignee: Yarra Valley Water Limited; Wang Industries Pty Ltd
Priority date: 2000-03-14
Filing date: 2001-03-14
Publication date: 2001-09-20
Also published as: AUPQ625100A0

Abstract

A pipeline isolating device comprising an expandable plug including a generally cylindrical body (1) adapted for insertion through an aperture (5) formed in the pipeline, the body including an expanding means (3) which may take the form of arms or an internal compliant boot having an inner contour shaped to cooperate with a plunger such that the expanding means can move between a first retracted position and a second expanded position so as to fully occlude the pipe and aperture.

Description

"Improved pipeline isolating device"

Introduction to the Invention

This invention relates to the maintenance of fluid or liquid carrying pipes and in particular to a device adapted for isolating a section of such piping to assist in maintenance work. In a particularly preferred aspect, the invention relates to the maintenance of water piping including town supply mains water piping.

Background to the Invention

The commercial supply of fluids or liquids via piping, either to industry or the domestic population is generally involved in the supply of a commodity on which industry or the domestic market rely. Accordingly, the maintenance involved in such piping work can result in considerable disruption to the supply of the fluid or liquid commodity and it is highly desirable to expedite such maintenance operations, thereby minimising disruption and downtime to said piping supplies. A particular example of such piping systems is the town supply of mains water which provides potable water to households and light industry from reservoirs via pumps and a network of underground piping.

The piping is generally configured as a branching network of pipes that diminish in dimensions ending with the street mains water pipes of about 100mm diameter running down and along suburban streets, past households and into which a plurality of individual households can tap. At the street level, the mains water pipes are provided with closeable gates at regular intervals every kilometer or so, to allow sections of pipeline to be isolated so as to allow maintenance thereof. However, the number of gates provided only allows isolation of a relatively large area which may affect up to 50 or so households. Accordingly, in the situations where considerable maintenance is required, the disruption to such a large number of households can be considerable and may involve health issues.

The mains water piping whilst principally provided for the supply of household water, also functions for emergency water supplied by way of fire hydrants or fire plugs, many of which are fitted at regular 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 the mains water system. The fire hydrants are connected to a generally horizontal supply of piping with a short generally vertical riser forming a tee junction with the supplied piping. This riser is then usually joined to a suitable connecting means such as a male threaded pipe section via a gate valve or other type of control valve. It would be very desirable if such fire hydrant access points could be utilised to shut off the mains water supply by acting as a temporary isolation gates. This would be particularly advantageous as the frequency of hydrants would allow a relatively small number of households to be affected by mains water pipe maintenance if such hydrant points could be used to isolate a section of mains water piping. Unfortunately, the equipment available to date, does not generally allow the ready access and occlusion of a fluid or liquid piping at a given diameter, via an access point or aperture formed in said piping which is of less diameter than the diameter of the piping to be occluded. The provision of such a device, particularly if such a device could allow insertion through an aperture and subsequent occlusion of a pipe of two or more sizes greater than said aperture would be highly advantageous and would of course allow fire hydrants to be used as access points for mains water piping.

Summary of Invention

In one aspect the invention provides a pipeline isolating device in the form of an expandable plug for occluding a liquid or fluid supply pipe wherein said plug is adapted to move between an expanded and unexpanded state such that said unexpanded plug is adapted for insertion into said supply pipe via an aperture smaller than the internal diameter of said supply pipe and when expanded said plug is adapted to occlude said supply pipe.

The expandable plug may include a first means to expand said plug to a first stage of expansion whereby the plug contacts a portion of the side wall of said supply pipe adjacent said aperture, and a second means to expand said plug to contact all of the side wall of said supply pipe and said aperture interface to occlude said pipe.

The expandable plug may comprise a body adapted for insertion through said aperture, a pair of arms adapted to move between a first retracted position within the confines of said body and a second expanded position beyond the confines of said body, and a compliant boot fitted over said body and adapted to move between a first constricted state and a second expanded stated.

The body may be provided with an expanding collar at or near its top for sealing the aperture entrance to said supply pipe.

The arms are preferably configured to substantially mirror the internal shape of the supply pipe to ensure snug abutment thereto in the second expanded position.

The arms may be further provided with inflatable lips to maximise sealing to said supply pipe.

The body of the plug is most preferably substantially cylindrical and dimensioned to allow ready insertion through said aperture whilst ensuring the boot and associated expanding collar have sufficient compliance to effect a seal about the interface with said aperture. The boot may be one piece or multiple pieces and is preferably shaped at its lower end to ensure snug abutment to the floor of said supply pipe.

The boot may be provided with optional restriction plates to selectively restrain expansion thereof to provide fluid corridors through said plug. The restriction plates may be positioned up and down the length of the body to selectively restrict expansion of said boot and/or said expanding collar.

The arms are most preferably operated by rack and pinion gearing to provide positive contact with said portion of said supply pipe so as to assist alignment and orientation of said plug prior to expansion of said boot. The boot is preferably operated hydraulically or pneumatically. The operating means of both arms and the boot means most preferably operate longitudinally through the length of said body to allow ready access and operation.

In another embodiment the expandable plug may comprise a body adapted for insertion through said aperture and an internal compliant boot with a displacement inner contour and a plunger adapted for fitting within said internal boot such that the movement of the plunger into and out of the boot causes the boot to move between the expanded and unexpanded state. The displacement contour is preferably configured to cause the boot to mirror the internal shape of the supply pipe. The body may also be provided with an expanding collar. The plug is most preferably adapted for use on mains water supply piping and particularly adapted to access said piping via fire hydrants associated with said mains water piping.

Brief Description of the Drawings

Figure 1 is a cross section side view of the expandable plug of the invention in its unexpanded state installed in a fire plug;

Figure 2 is a cross section plan view of the expandable plug in its unexpanded state installed in a fire plug; Figure 3 is a cross section end view of an expandable plug installed in a fire plug in its unexpanded state;

Figure 4 is a cross section plan view of the expandable plug installed in a fire plug in its first expanded state; and

Figure 5 is a cross section end view of the expandable plug installed in a fire plug in a further expanded state.

Figure 6 is a cross section side view of another embodiment of the plug in its unexpanded state.

Figure 7 is a cross section view of another embodiment of the invention.

Detailed Description of the Invention

The expandable plug of the invention can take many forms and is adapted for use in the maintenance of any fluid or liquid piping including water, gas, oil, fuel etc., but will be described with reference to two particularly preferred embodiments as shown in Figures 1 to 5 and 6, 7 which reference the application of the invention to the isolation of mains water supply piping via fire hydrant access.

EXAMPLE ONE Referring firstly to Figures 1, 2 and 3, the isolating device of the invention is shown as installed through a street fire hydrant and positioned at the bottom of a tee joint intercepting the mains water pipe. Figures 1, 2 and 3 show the plug in its unexpanded state in a side, plan and end view respectively. The expandable plug comprises a body 1 of generally cylindrical configuration and dimensioned to fit within the confines of the tee. The body 1 is provided with a pair of moveable arms 2 which can be moved from a first retracted position, fully occupied within the confines of the body 1 to a second expanded position abutting the inner side wall 20 of the mains pipe 6, or tee joint. The expandable plug further includes a compliant bladder or boot 3 which is drawn over the whole of the body 1, including the arms 2, and sealed at the top of the body at or near a top rim 23. The compliant boot is adapted to move from an unexpanded state or contracted state to a second expanded state upon inflation with air or fluid. The expansion of the arms 2, either side of the body, cause the boot to move out and abut the side wall 20 of the supply pipe 6 thereby serving to partially occlude the water pipe; and, importantly, to serve as an aligning means to ensure the plug is positioned correctly before inflation or expansion of the boot 3. Once the plug is correctly positioned, the boot 3 is expanded by inflation from air or water which causes the boot to blow out and completely occlude the water pipe 6 in the region of the tee joint. The body may be provided at its upper end with an expanding collar 4 which is positioned around the aperture of the hydrant rise and neck of the tee 5. The expanding collar 4 is adapted to assist the boot 3 to ensure that the expandable plug fully occludes, not only the water pipe 6, but also the hydrant rise region 5. In order to further assist the sealing of the plug, the arms 2 may be provided with inflatable lips 7 along the edges thereof, which are inflatable by hydraulic or pneumatic means 21 such that once the arms are in the expanded state, the inflatable lips can be activated thereby ensuring particularly snug and firm engagement of the plug to the side wall 20 of the water pipe 6 thereby preventing any tendency of the plug to rotate during expansion. The dimensions of the body 1 are designed in such a way that sufficient space is allowed around the aperture 5 to provide easy insertion and removal; but, the dimension is sufficiently small to ensure the expansion collar 4 and action of the boot 3 are not overextended and are able to provide adequate sealing. The boot 3 may be a one-piece fully contained unit which seals around the top rim 23 of the body 1 and is shaped at its lower end 8 in a convex manner to ensure snug engagement of the floor 9 of the water pipe. In an alternative embodiment the boot may be provided in multiple parts, each independently operated and sealable in their own right. The boot may be provided with optional restriction plates 10 in the form of rigid plates which compress the outside of the boot 3 and are fitted to the body 1. The restriction plates may be bolted to the body. The restriction plates can be used to selectively restrain the expansion of the boot 3 so as to provide a limited corridor through which fluid can pass once the plug of the invention has been activated. In this manner the restriction plates can provide corridors for simultaneously sealing the down or upstream side of a hydrant tee whilst allowing movement of water up the alternative side, so as to provide a conduit for selective movement of fluid or water by passing said plug. The restriction plates can be positioned up or down the length of the body and can optionally be placed in a position to restrict the expansion of not only the boot 3 but the expanding collar 4.

The arms 2 are preferably operated mechanically by way of rack and pinion gearing with the arms having gear racks 11 which are driven by drive pinions 12 that are in turn activated by longitudinal drive shafts 13 fitted coaxially along the length of the body 1. The body 1 may be provided with a gearbox 18 on the top thereof which is provided with a slave pinions 15 and a central pinion 16 which is in turn driven by a axial handle shaft 17; thereby allowing ready activation of the plug from a distance up the hydrant rise 5. The boot 3 is preferably operated hydraulically or pneumatically and is accessed by way of a valve 19 positioned at or within the body or the associated gearbox 18. In this manner, the body and gearbox combination are configured to provide a continuous conduit for the various mechanical and hydraulic/pneumatic activation of the plug. The activation of the inflatable lip 7 can be provided by lip inflating hydraulics 21 which are also conduited through the body 1, gearbox 18, and accessed out of the hydrant aperture 5. Referring now to Figures 4 and 5, a cross section, plan and end view of the expandable plug of the invention is shown with the plug in its various expanded states. Figure 4 details the action of the expanding arms 2 as they move outside the confines of the body 1 to abut the side wall 20 of the supply pipe 6 or the tee region, where the hydrant intercepts with the supply piping. The action of the gearbox is clearly shown with the central pinion 16 being driven remotely by the handle shaft extending therefrom. The central pinion serves to activate two slave pinions 15 which, as previously described, activate drive shafts 13, drive pinions 12 and gear racks 11 formed on the sides of the arms 2. The end view shown in Figure 5 clearly details how the expanded arms

2 are drawn out to snugly abut the side wall 20 of the hydrant tee and also serve to draw out that region of the boot 3 overlapping the arms. Whilst the expansion of the arms alone serve to substantially occlude the movement of water passed the hydrant tee, the arms being of limited width do not on their own, fully occlude movement of water up and down the vertical hydrant rise 5 and it is the expansion of the boot 3 that serves to fully close off the aperture entrance 5.

EXAMPLE TWO

Another embodiment of the invention is shown in Figures 6 and 7 where the rubber boot 3 takes an alternative design to the previous example and includes an inner displacement profile which is adapted to cooperate with a plunger 24 fitted within the confines of the body 1. The plunger is adapted for moving longitudinally into and out of the boot 3 such that the movement of the plunger into the boot 3 causes the inner profile to displace, thereby effecting the movement of the boot in an outward fashion so as to cause the occlusion of the pipe as the boot is drawn out against side wall 20 of the supply pipe. In this manner, the alternative embodiment of the expandable plug has replaced the arms with the inner boot and provides a highly efficient and simplified operation of the invention. The boot 3 may be provided with an optional void 25 so as to provide selective expansion of the boot around the top of the body so as to provide corridors or conduits for water movement bypassing the principal occlusion. In this manner the void can provide corridors for simultaneously sealing the down or upstream side of the hydrant tee whilst allowing movement of water up the alternative side in order to provide a conduit for selective movement of fluid or water bypassing said plug. The plunger may be made of steel or other rigid material and is moved longitudinally up and down by way of hydraulic or pneumatic power.

In use this embodiment of the invention would be installed down a fire hydrant in its fully contracted state with a plunger drawn in the up position, removed from the displacement contour or the inside of the boot. In this manner, the device can be readily placed down the hydrant rise 5 and once the device is fully located at the bottom of the hydrant tee such that the boot is snuggly abutting the floor 9, the operator would open the valve of the hydraulic or pneumatic cylinder causing the plunger to move down and thereby causing the inner contour of the boot to be pushed outward and causing the boot to move out and be drawn up against the side of the supply pipe, thereby occluding the joint.

Of course, various situations may arise where it is desirable to conduit water in and out of an isolated section of pipe. In particular, where an isolated section, having been subject to maintenance, requires cleansing or chlorination in order to ensure sanitation. Such access to the isolated section of piping alone would be desirable and this can be accomplished by way of the restriction plates 10 which can allow independent access to the isolated section of water mains whilst not in any way interfering with the remainder of the piping system.

In use, the invention finds application in virtually any situation where a fluid or liquid carrying pipe requires interception and isolation; particularly where an aperture smaller than the diameter of the main pipe is available. In the case of a mains water maintenance situation, the area of mains water piping require maintenance would be identified and sections either side provided with fire hydrants would be closed off and the isolating device of the invention would be installed down the fire hydrant. The installation would be affected with the expandable plug in its fully contracted state which takes the form of a substantially cylindrical device which can be placed down the hydrant rise 5 of a water hydrant. Once the device is fully located at the bottom of the hydrant tee such that the boot 3 is snugly abutting the floor 9 of the tee in that area of the water pipe, the operator would rotate the handle shaft 17 thereby causing the arms 3 to move out from within the confines of the body, drawing that section of surrounding boot 3 with them, and drawing the arms into abutment with the side wall 20 of the hydrant tee. Once this is accomplished, if necessary, the inflatable lips 7 can be activated to ensure snug and secure location of the expandable plug in the appropriate orientation in the pipeline. At this stage, the boot 3 would be expanded by hydraulic or pneumatic activation through the valve 19 such that pressure within the boot causes the boot to expand out fully occluding the tee and thereby serving to fully isolate that section of mains water piping between the two respective hydrants. If access to the mains water from that same hydrant is required and/or fluid access is required to the isolated part of the mains, then restriction plates 10 could be installed prior to insertion of the expandable plug in the fire hydrant such that a corridor or conduit is provided up either side of the expandable plug and out of the hydrant. These corridors or conduits could be used to access the mains water and/or provide a means of chlorinating or otherwise back-flushing that section of piping isolated for maintenance work.

The advantages of the invention are numerous, particularly including the ability to readily access piping through an aperture available therein or one formed two or more sizes down from the diameter of pipe requiring maintenance. This provision alone allows for a great increase in maintenance efficiency but most importantly allows the invention to be used in situations where ready access points are available, for example, fire hydrant access to mains water systems. The invention also provides a means of closing off any size piping where a cut-out from that piping is limited. In applications where more than two sizing are required to be traversed, the invention can provide modifications where, for example, the expanding arms include multiple complementary elements where the arms can be made up of a series of concertinaed units allowing great expansion over many sizes.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS:

1. A pipeline isolating device comprising an expandable plug for occluding a liquid or fluid supply pipe wherein said plug is adapted to move between an expanded and an unexpanded state such that said unexpanded plug is adapted for insertion into said supply pipe via an aperture smaller than the internal diameter of said supply pipe and when expanded said plug is adapted to occlude said supply pipe.

2. An isolating device according to claim 1 wherein said expandable plug includes a first means to expand said plug to a first stage of expansion whereby the plug contacts a portion of the side wall of said supply pipe adjacent said aperture and a second means to expand said plug to contact all of the side wall of said supply pipe and said aperture interface to occlude said pipe.

3. An isolating device according to claim 1 or 2 wherein said expandable plug comprises a body adapted for insertion through said aperture and wherein said first means are pair of arms adapted to move between a first retracted position within the confines of said body and a second expanded position beyond the confines of said body and wherein said second means is a compliant boot fitted over said body and adapted to move between a first constricted state and a second expanded state.

4. An isolating device according to claim 3 wherein said body is provided with an expanding collar at or near its top for sealing said aperture at or near its interface to said supply pipe.

5. An isolating device according to claim 3 or 4 wherein said arms are configured to substantially mirror the internal shape of said supply pipe to ensure snug abutment thereto in the second expanded position.

6. An isolating device according to any one of claims 3 to 5 wherein said arms are provided with inflatable lips to maximise sealing to said supply pipe.

7. An isolating device according to any one of claims 3 to 6 wherein said body is substantially cylindrical and dimensioned to allow ready insertion through said aperture whilst ensuring said boot and said expanding collar have sufficient compliance to effect a seal about the interface with said aperture.

8. An isolating device according to any one of claims 3 to 7 wherein said boot is shaped at its lower end to ensure snug abutment to the floor of said supply.

9. An isolating device according to claim 8 wherein said boot is formed in one piece.

10. An isolating device according to claim 8 wherein said boot is formed in two pieces.

11. An isolating device according to any one of claims 3 to 10 wherein said boot is provided with optional restriction plates adapted to selectively restrain expansion of said boot to provide fluid corridors through said plug.

12. An isolating device according to claim 11 wherein said plates are adapted for fitting to said body to selectively restrict the expansion of said boot and said collar.

13. An isolating device according to any one of claims 3 to 12 wherein said arms are operated by rack and pinion gearing.

14. An isolating device according to any one of claims 3 to 13 wherein said boot is operated hydraulically.

15. An isolating device according to any one of claims 3 to 13 wherein said boot is operated pneumatically.

16. An isolating device according to any one of claims 3 to 15 wherein the operating means of said arms and said boot operates longitudinally through the length of said body to allow ready access and operation thereof.

17. An isolating device according to claim 3 or 4 wherein said arms comprise an internal compliant boot with a displacement inner contour and a plunger adapted for fitting within said internal boot such that the movement of said plunger into and out of said boot causes the boot to move between said first retracted position and said second expanded position.

18. An isolating device according to claim 17 wherein said plunger is operated hydraulically or pneumatically.

19. A method of isolating a mains water pipe comprising the use of a device according to any one of claims 1 to 18 wherein said aperture is provided by a fire access point on said piping.

20. An isolating device according to any one of claims 1 to 18 substantially as hereinbefore described with particular reference to the examples.

21. A method according to claim 19 substantially as hereinbefore described with particular reference to the examples.