AU2019258599A1

AU2019258599A1 - A pipe plug device, a system and methods of use thereof

Info

Publication number: AU2019258599A1
Application number: AU2019258599A
Authority: AU
Inventors: David Nichols
Original assignee: I Pipe Ip Pty Ltd
Current assignee: I Pipe Ip Pty Ltd
Priority date: 2018-04-26
Filing date: 2019-04-26
Publication date: 2020-10-15
Also published as: WO2019204878A1

Abstract

A pipe plug device, a system including the pipe plug device and methods of use thereof for stopping flow of fluid in a pipe. The pipe plug device includes an elongate body having a pair of opposed end plates. The body extends longitudinally between the opposed end plates and is configured to be axially inserted into the pipe via a connection into the pipe. The device further includes at least one expandable portion located about an outer periphery of the body between opposed end plates. The expandable portion is configured to receive an expansion fluid and expand to sealingly engage with an inner surface of the pipe to stop the flow of fluid in the pipe.

Description

A PIPE PLUG DEVICE, A SYSTEM AND METHODS OF USE THEREOF TECHNICAL FIELD

[0001 ] The present invention relates to pipe plug device, a system including at least one pipe plug device and methods of use thereof for stopping a flow of a fluid in a pipe.

BACKGROUND

[0002] Pipeline systems are commonly used for the transport of goods, such as, e.g., crude and refined petroleum, fuels including oil, natural gas and biofuels, and other fluids such as sewage, slurry or water. Such systems are typically formed from steel or plastic materials and generally convey the goods over vast distances.

[0003] Pipeline systems typically include numerous components, including lengths of pipe joined end-to-end, compressor/pump stations, valves and manifolds.

[0004] With pipeline systems it is advantageous to be able to temporarily isolate a portion of the pipeline to, e.g., perform maintenance, repair and/or replacement operations on the portion. It is even more advantageous if such operations can be performed while the system is live by, e.g., enabling the flow of goods to bypass the portion undergoing maintenance, repair and/or replacement operations.

[0005] Currently, the preferred method of temporarily isolating a portion of a pipeline is to “squeeze-off” the portion with a clamp fitted to the pipeline immediately before the portion to be isolated. However, the problem with such squeeze-off methods is that it damages the wall of the pipeline thereby presenting further problems.

[0006] Other methods for isolating a portion of a pipeline include “bagging off” and “plugging” the pipeline immediately before the portion to be isolated to stop the flow of goods into the portion.

[0007] “Bagging off” utilises an inflated bag inserted into the pipeline to stop the flow. However, problems with such a method is that it is only really applicable to stopping a low pressure flow and the method is not failure proof, e.g., the bag can rupture.

[0008] “Plugging” utilises a mechanical plug inserted into a pipeline to stop the flow. However, a problem with such a method is that the plug is generally only sized and shaped to fit a pipeline having a particular diameter. Consequently, the plug when used with slightly larger diameter pipes than designated typically does not provide an effective seal. Conversely, the plug is unable to be used with smaller diameter pipes.

SUMMARY OF INVENTION

[0009] Embodiments of the present invention provide a pipe plug device, a system including the device and methods of use thereof, which may minimise or overcome at least one of the problems mentioned above, or which may provide the public with a useful or commercial choice.

[0010] According to a first aspect of the present invention, there is provided a pipe plug device for stopping a flow of fluid in a pipe, said device including:

an elongate body having a pair of opposed end plates, said body extending longitudinally between the opposed end plates, said body configured to be axially inserted into the pipe via a connection into the pipe; and

at least one expandable portion located about an outer periphery of the body between the opposed end plates, said at least one expandable portion configured to receive an expansion fluid for expanding the at least one expandable portion to sealingly engage with an inner surface of the pipe and stop the flow of fluid in the pipe.

[001 1 ] According to a second aspect of the present invention, there is provided a pipe isolation system for stopping a flow of fluid in a pipe, said system including:

at least one pipe plug device configured to be axially inserted into the pipe, said device including:

an elongate body having a pair of opposed end plates, said body extending longitudinally between the pair of opposed end plates; and

at least one expandable portion located about an outer periphery of the body between the opposed end plates, said at least one expandable portion configured to receive an expansion fluid for expanding the at least one expandable portion to sealingly engage with an inner surface of the pipe and stop the flow of fluid in the pipe;

a connection into the pipe through which the device is inserted; and

a source of the expansion fluid connectable to the device for supplying the expansion fluid at least into the at least one expandable portion for expanding said portion.

[0012] Advantageously, the device and method of the present invention provides a means of readily stopping a flow of fluid in a live pipeline via any generic connection fitting. The expandable portion of the device enables the device to effectively stop a flow of fluid across a broad range of pipe sizes, including pipes having substantially larger diameters than the device itself. Moreover, by having an expandable portion configured to expand upon receiving an expansion fluid, the device has fewer moving parts and is therefore less prone to failure than existing mechanical plugs. Conversely, by having an elongate body, including opposed end plates and a shaft extending therebetween, the device is also less prone to failure than conventional balloons used in“bagging off” procedures.

[0013] As indicated above, the pipe plug device of the present invention is configured to be axially inserted into a pipe via a connection to stop the flow of a fluid in the pipe.

[0014] Generally, the pipe may be part of a pipeline for conveying a fluid medium, such as, e.g., crude and refined petroleum, fuels, oil, natural gas, coal seam gas, biofuel or other fluids. Such pipelines typically span vast distances and are formed from segments or lengths of pipe joined end-to-end.

[0015] The individual pipes forming such pipelines are usually formed from metal and/or plastic material or materials, such as, e.g., high density polyethylene.

[0016] The connection for inserting the pipe plug device into a pipe may include a fitting, such as, e.g., a saddle or tee fitting. The connection is preferably made without interrupting a flow of fluid in the pipe or emptying the pipe.

[0017] Such fittings generally include a base configured to be fastened atop at least part of an outer surface of a sidewall of the pipe where the pipe plug device is to be inserted and at least one inlet through which various tools may be at least partially inserted and operated, including the pipe plug device of the present invention.

[0018] In some embodiments, the base may be a sleeve or part thereof configured to be fastened at least partially about the outer surface of the sidewall of the pipe.

[0019] In other embodiments, the base may include a lower edge configured to be fastened atop the at least part of the outer surface of the sidewall of the pipe.

[0020] The at least one inlet may extend outwardly from the base in a direction substantially perpendicular to a longitudinal direction of the pipe. The inlet may include a flanged outer opening for connecting various tools, such as, e.g., a hole saw for making an opening in the sidewall of the pipe or a temporary valve.

[0021 ] Once the pipe plug device of the present invention has stopped the flow of fluid in a pipe, the device may be removed and the connection may be closed with a closing element, such as, e.g., a mechanical plug or valve.

[0022] The elongate body may be of any suitable size, shape and construction, and formed from any suitable material or materials to be axially inserted into a pipe and sealingly engage the inner surface of the pipe when the at least one expandable portion is expanded.

[0023] For example, the elongate body may be sized and shaped to be axially inserted into a pipe having a minimal nominal diameter (“DIM”) of between about 50mm and about 600mm. For example, the elongate body may be sized and shaped to be axially inserted into a pipe having a minimal nominal diameter (“DIM”) of at least 50mm, at least 100mm, at least 125mm, at least 150mm, at least 160mm, at least 175mm, at least 200mm, at least 225mm, at least 250mm, at least 275mm, at least 300mm, at least 325mm, at least 350mm, at least 375mm, at least 400mm, at least 425mm, at least 450mm, at least 475mm, at least 500mm, at least 525mm, at least 550mm, at least 575mm or even at least 600mm or more.

[0024] Similarly, the elongate body may be sized and shaped to sealingly engage an inner surface of a pipe having a maximum DN of between about 100mm and about 2,000mm. For example, the elongate body may be sized and shape to sealingly engage an inner surface of a pipe have a maximum DN of about 100mm, about 200mm, about 300mm, about 400mm, about 500mm, about 600mm, about 700mm, about 800mm, about 900mm, about 1 ,000mm, about 1 ,100mm, about 1 ,200mm, about 1 ,400mm, about 1 ,500mm, about 1 ,600mm, about 1 ,800mm or even about 2,000mm or more.

[0025] The elongate body may typically be formed from a durable and substantially rigid material or materials, such as, e.g., plastic or metal material or materials.

[0026] The body includes at least two opposed end plates and preferably a shaft extending therebetween.

[0027] The two opposed end plates may have any suitable profile shape and may be of any suitable thickness. For example, each end plate may have a profile shape that is rectangular, circular, triangular, pentagonal, hexagonal, heptagonal, and octagonal or any variation or combination thereof. Typically, each end plate will have a substantially circular profile shape.

[0028] Likewise, the shaft extending between the opposed end plates may be of any suitable size, shape and construction. For example, the shaft may be of tubular or of solid construction. Typically, the shaft may have a substantially cylindrical shape having two opposed ends and at least one curved sidewall extending therebetween.

[0029] The shaft may have a constant diameter or the diameter may at least partially change along a length of the shaft. Any change in diameter may be a gradual or stepped change, for example. [0030] For example, in some embodiments, the shaft may include one or more stepped portions having differing diameters. For example, the shaft may include two outer portions and a central portion located between the two outer portions. In some such embodiments, the two outer portions may have a greater diameter than the central portion. In other such embodiments, the central portion may have a greater diameter than the outer portions.

[0031 ] The shaft may be of any suitable length for defining a space between the opposed end plates for the at least one expandable portion. For example, the shaft may have a length ranging between about 50mm and about 1 ,000mm. The shaft may have a length of at least 50mm, at least 60mm, at least 70mm, at least 80mm, at least 90mm, at least 100mm, at least 1 10mm, at least 120mm, at least 130mm, at least 140mm, at least 150mm, at least 160mm, at least 170mm, at least 180mm, at least 190mm, at least 200mm, at least 210mm, at least 220mm, at least 230mm, at least 240mm, at least 250mm, at least 260mm, at least 270mm, at least 280mm, at least 290mm, at least 300mm, at least 310mm, at least 320mm, at least 330m, at least 340mm, at least 350mm, at least 360mm, at least 370mm, at least 380, at least 390mm, at least 400mm, at least 410mm, at least 420mm, at least 430mm, at least 440mm, at least 450mm, at least 460mm, at least 470mm, at least 480mm, at least 490mm, at least 500mm, at least 550mm, at least 600mm, at least 650mm, at least 700mm, at least 750mm, at least 800mm, at least 850mm, at least 900mm, at least 950mm or even at least 1 ,000mm. Usually, the shaft may have a length between about 100mm and about 400mm.

[0032] The end plates and the shaft may be joined in any suitable way. For example, in some embodiments, the end plates and the shaft may be integrally formed. In other embodiments, each end plate may be connected to an end of the shaft, typically releasably connected, preferably threadingly connected. Each end plates may be centrally aligned relative to the shaft.

[0033] Each end plate may have opposed surfaces extending substantially parallel to one another, including an outer surface and an opposed inner surface. The opposed surfaces may be interconnected by at least one side edge. In some embodiments, the at least one side edge may be partially rounded or chamfered, preferably at or near the outer surface. In other embodiments, the at least one side edge may be rounded or have a conical shape.

[0034] In some embodiments, each end plate may further include a rim and at least one sidewall extending inwards from, or away from, the inner surface to the rim. The rim may extend along a distal portion or outer edge of the sidewall. Preferably, the at least one sidewall may extend orthogonally inwards from each end plate at least partially towards the opposed end plate. [0035] As indicated above, each of the opposed end plates may preferably be threadingly connected to a respective end of the shaft.

[0036] In one such embodiment, each end of the shaft may include a threaded protrusion configured to threadingly engage with a corresponding opening defined in a central portion of at least an inner surface of an end plate.

[0037] In another such embodiment, each end plate may include a threaded protrusion extending outwardly from an inner surface of the end plate and configured to threadingly engage with a corresponding opening defined in an adjacent end of the shaft.

[0038] The at least one expandable portion may be of any suitable size, shape and construction and formed from any suitable material or materials to be expandable about the elongate body and sealingly engage the inner surface of the pipe.

[0039] For example, the at least one expandable portion may be formed from a resiliently deformable material or materials, such as, e.g., rubber or plastic material or materials. Preferably, the material or materials may be substantially impermeable so as to contain the expansion fluid.

[0040] The at least one expandable portion may be of unitary construction or may be formed from two or more portion pieces.

[0041 ] In some embodiments, the expandable portion may be a sealed bag or container with an opening for receiving and releasing the expansion fluid.

[0042] In other embodiments, the expandable portion may not be sealed.

[0043] For example, in some such embodiments, the expandable portion may further include a bladder configured to be located within the expandable portion. The bladder may include an opening for receiving and releasing the expansion fluid. In use, the bladder may receive and become pressurised with the expansion fluid and, in turn, push out the expandable portion to sealingly engage the inner surface of the pipe.

[0044] In other such embodiments, the at least one expandable portion may be in the form of a sleeve, preferably a cylindrically-shaped sleeve, more preferably a cylindrical-shaped sleeve with open opposed ends. In such embodiments, the at least one expandable portion may be connectable to the elongate body to sealingly contain the expansion fluid and be expandable. This will be described in detail later. [0045] The expandable portion may preferably include opposed open ends and at least one membrane extending therebetween. In use, the expandable portion may be fitted about the shaft of the elongate body with each of the opposed open ends abutting against the inner surface of an adjacent end plate. The membrane may preferably extend continuously about the shaft of the elongate body.

[0046] The open ends of the expandable portion may be of any suitable shape to be fitted around the shaft and preferably be connectable to the end plates of the elongate body.

[0047] For example, in some embodiments, the open ends may be in the shape of a square, triangle, rectangle, pentagon, hexagon or octagon.

[0048] In other embodiments, the open ends may be in the shape of a circle or oval.

[0049] Each open end of the expandable portion may be defined by a rim extending along an end edge portion of the at least one membrane.

[0050] In some embodiments, the at least one expandable portion may include a shaped collar defining each of the opposed open ends. Each shaped collar may be formed from an annular portion of the expandable portion located adjacent to and around a periphery of the open end. The shaped collar may be thicker than remaining portions of the expandable portion.

[0051 ] The at least one membrane may be of any suitable size, shape and construction. Generally, the at least one membrane may transition between a resting state and an expanded state.

[0052] In the resting state, the at least one membrane may preferably have a cross sectional width, measured between opposed sides of the expandable portion, that is not greater than a maximum width of the end plates of the elongate body.

[0053] Of course, in the expanded state, the at least one membrane will have a cross sectional width greater than the maximum width of the end plates of the elongate body.

[0054] In some embodiments, the expandable portion in the resting state may have a shaped resting shape. The expandable portion may resiliently return to the shaped resting shape when the expansion fluid has been released or removed.

[0055] For example, in some such embodiments, the membrane of the expandable portion may extend linearly between outer edges of the opposed open ends, preferably the rim or the opposed shaped collars defining the open ends, when the expandable portion is in the resting state.

[0056] In other such embodiments, the membrane of the expandable portion may include one or more corrugations. The corrugations may at least partially extend about the membrane of the expandable portion, preferably in a lateral direction relative to a longitudinal length of the membrane extending between the open ends. The corrugations may be in the form of indentations or depressions extending at least partially about the expandable portion.

[0057] The corrugations may at least partially strengthen the membrane when the expandable portion is in the resting state. The corrugations may also advantageously increase the surface area of the membrane and thereby increase the size that the expandable portion may expand when in the expanded state.

[0058] In some embodiments, the membrane of the expandable portion may include more than one corrugation extending about the expandable portion. For example, the membrane may include two, three, four, five, six, seven, eight, nine or even 10 corrugations extending about the expandable portion, preferably parallel to one another.

[0059] A person skilled in the art will appreciate, however, that many factors can be customised to provide a desired balance of strength and expandability. These include, by way of example and not by way of limitation, the depth of the corrugations, the thickness of the membrane at those locations, the sharpness of the angle of indentation of the corrugations with respect to adjacent membrane areas, the angularity of corrugations or smoothness in cross- section, the frequency and regularity of the pattern of the corrugations, the spacing between the corrugations and other factors.

[0060] In some embodiments, the outer surface of the membrane of the expandable portion may include one or more protrusions protruding out from the outer surface to assist in forming a substantially water/gas-tight seal with the inner surface of a pipe when in the expanded state. The one or more protrusions may be of any size, shape and form. Generally, however, the one or more protrusions may each be in the form of ribbing extending at least partially about the expandable portion, preferably entirely about in a lateral direction relative to the longitudinal length of the expandable portion.

[0061 ] The at least one expandable portion may be connectable to the elongate body in any suitable way to sealingly contain the expansion fluid and be expandable. As indicated above, the expandable portion is preferably in the form of a sleeve located about the shaft of the elongate body with the open ends of the expandable portion being sealingly connected to the opposed end plates. [0062] The at least one expandable portion may define an expansion fluid receiving volume about the shaft and the inner surfaces of the end plates of the elongate body.

[0063] In some embodiments, for example, the rims or shaped collars defining the open ends of the expandable portion and the inner surface of the opposed end plates of the elongate body may be fastened together with at least one fastener. The at least one fastener may include one or more mechanical fasteners and/or one or more chemical fasteners.

[0064] The one or more chemical fasteners may include a wet adhesive, a dry adhesive and/or double-sided adhesive tape that may extend between the rim or shaped collar and the inner surface.

[0065] The one or more mechanical fasteners may include threaded fasteners, which may extend through openings defined in or near the rim or the shaped collar and into the inner surface.

[0066] In other embodiments, the rim or shaped collar and the inner surface may connected together by a connecting mechanism or part of a connecting mechanism. The connecting mechanism or part of the connecting mechanism may be of integral formation with each rim or shaped collar and the end plates of the elongate body.

[0067] The connecting mechanism may include mateable male and female portions that couple together, such as, e.g., a threaded connection or an interference fit (snap fit) connection.

[0068] For example, in some embodiments, the rims or shaped collars defining the open ends of the expandable portion may each include a female formation associated with the rim or shaped collar configured to at least partially receive or be coupled with a male formation associated with each end plate of the elongate body.

[0069] Conversely, in other embodiments, the rims or shaped collars defining the open ends of the expandable portion may each include a male formation associated with the rim or shaped collar configured to be at least partially inserted into or coupled with a female formation associated with each end plate of the elongate body.

[0070] For example, in one such embodiment, the male formation may be in the form of the rim or shaped collar having a narrower diameter configured to be at least partially received in the female formation in the form of a wider rim formed by the at least one sidewall of each end plate.

[0071 ] In some embodiments, an outer surface of the rim or shaped collar of the expandable portion may further include one or more indentations extending at least partway around the rim or shaped collar. An inner surface of the wider rim of the end plate may include one or more corresponding resilient projections that engage with and are at least partially received in the one or more indentations when the expandable portion and the end plate are connected together.

[0072] In other embodiments, the outer surface of the rim or shaped collar of the expandable portion may include one or more resilient projections extending at least partway around the rim or shaped collar. The inner surface of the wider rim of the end plate may include one or more corresponding indentations configured to engage with and at least partially receive the one or more resilient projections.

[0073] In some embodiments, a gasket or sealing member and/or a sealing agent may be attached to or applied along one or both of each rim or shaped collar of the expandable portion and an inner surface of each end plate of the elongate body to assist in forming a substantially water/gas-tight seal. For example, the gasket or sealing member may be in the form of a strip of foam attached to one or both of each rim or shaped collar of the expandable portion and an inner surface of each end plate of the elongate body to be joined or connected. Any suitable sealing agent such as, e.g., mastic sealant or the like may be used.

[0074] In some embodiments, the elongate body may further include a pair of clamping members each for clamping the rim or shaped collar defining an open end of the expandable portion against an adjacent end plate of the elongate body.

[0075] Each clamping member may be of any suitable size, shape and form and may be associated with the elongate body in any suitable way.

[0076] In some embodiments, the clamping members may be fixedly mounted to the shaft of the elongate body.

[0077] For example, in some such embodiments, each clamping member may be fastened in place to a portion of the shaft of the elongate body near an adjacent end plate. Any suitable type of mechanical or chemical fastener may be used.

[0078] In other such embodiments, each clamping member may be threadingly mounted over an end portion of the shaft of the elongate body prior to an adjacent end plate being connected. For example, each clamping member may include an internally threaded central aperture configured to threadingly engage a threaded protrusion associated with the end of the shaft of the elongate body.

[0079] In yet other such embodiments, each clamping member may be connected in place in an interference-type connection.

[0080] In other embodiments, each clamping member may be slidably mounted to a portion of the shaft of the elongate body near an adjacent end plate. For example, each clamping member may include a central aperture configured to receive the at least a portion of the shaft of the elongate body in a sliding arrangement. In such embodiments, the clamping member may slide against and clamp the rim or shaped collar of the expandable portion as the expansion fluid receiving volume is filled and pressurised with the expansion fluid.

[0081 ] Generally, in such embodiments, each clamping member may further include at least one sealing member located at least partially around an edge of the central aperture to assist in forming an at least partial seal about the portion of the shaft of the elongate body. The formation of the at least partial seal at least partially prevents leakage of the expansion fluid around the clamping member via the central aperture. This, in turn, assists in sliding the clamping member against the rim or shaped collar of the expandable portion when the expansion fluid receiving volume is filled and pressurised with the expansion fluid.

[0082] The at least one sealing member may be of any suitable size, form and shape. Typically, however, the at least one sealing member may be in the form of an O-ring. An outer edge of the O-ring is at least partially received in a corresponding groove defined in the edge of the central aperture such that a protruding inner edge of the O-ring is able to form the at least partial seal about the portion of the shaft of the elongate body. Preferably, the central aperture of each clamping member may include at least two O-rings seated in corresponding grooves arranged in series.

[0083] In preferred such embodiments, the shaft of the elongate body may include at least one retaining member associated with or near each clamping member to prevent the clamping member from sliding towards an opposite end of the shaft. The retaining member may be of any suitable size, shape and form. Generally, the retaining member may be in the form of a stepped central portion of the shaft having a greater diameter or width than the central aperture of each clamping member.

[0084] In yet other embodiments, the device may include an actuating mechanism for moving the clamping members towards and away from an adjacent end plate. The actuating mechanism may be adjustable to enable the clamping pressure to be adjusted.

[0085] Any suitable type of mechanism may be used. The actuating mechanism may be manually actuated or by using a drive, for example. Movement may be linear, although non linear movement such as rotary movement is also envisaged. [0086] For example, if manually actuated, the actuating mechanism may include one or more of a lever, ram, operable handle, sliding arrangement (e.g., one or more shafts/columns extending through one or more apertures in the clamping members, tongue in groove), hinged arrangement or pivoting arrangement for moving the clamping members towards and away from the adjacent end plates.

[0087] The actuating mechanism may include one or more biasing mechanisms or members so that movement of each of the clamping members towards an adjacent end plate works against the force of the biasing mechanism or member and so that the clamping members move away from the adjacent end plate under the force of the biasing mechanism or member.

[0088] The biasing mechanism or member may be one or more springs, such as coil or leaf springs, for example. In another example, the biasing mechanism or member may be a spacer or the like positioned at least between each clamping member and an adjacent end plate. Of course, a person skilled in the art will appreciate that other types of biasing mechanisms or members such as magnets or magnetized elements and the like may be used.

[0089] Typically, each clamping member may include a clamping plate mountable near an end of the shaft of the elongate body for clamping the rim or shaped collar of the expandable portion against the inner surface of an adjacent end plate of the elongate body.

[0090] The clamping plates may be of like size and shape or not, preferably like. Each plate may be substantially rectangular, oblong, circular, ellipsoidal or oval in shape, preferably substantially circular. Each plate may be of unitary construction or may be formed from two or more plate pieces, for example.

[0091 ] Each clamping plate may have two opposed surfaces, including a clamping surface and an opposed outer surface. The opposed surfaces may extend substantially parallel to one another and be interconnected by at least one side edge.

[0092] In some embodiments, each clamping plate may further include a liner or coating at least on a portion of the clamping surface to at least partially assist in clamping the rim or shaped collar against the adjacent end plate. The liner or coating may be of any suitable size, shape and construction and formed from any suitable material or materials.

[0093] Generally, the liner or coating may be formed from a resiliency deformable material or materials, such as, e.g., rubber or soft plastic material or materials.

[0094] In other embodiments, each clamping plate may further include a pad extending at least partially across the clamping surface to at least partially assist in clamping the rim or shaped collar against the adjacent end plate.

[0095] Again, the pad may typically be formed from a resiliently deformable material or materials, such as, e.g., rubber or soft plastic material or materials.

[0096] The expansion fluid may be any suitable fluid able to be supplied into the pipe plug device under pressure and expand the at least one expandable portion. The expansion fluid may be a liquid or gas. For example, the expansion fluid may include water, oil (hydraulic oil), gas, nitrogen gas, or air. Preferably, the expansion fluid may be an inert fluid.

[0097] The elongate body preferably includes at least one passage extending from at least one expansion fluid inlet associated with either an externally accessible end of the shaft or one of the pair of opposed end plates and at least one expansion fluid outlet located on the shaft at a position between the two opposed ends of the shaft. The expansion fluid receiving volume may be in fluid communication with the passage. A part or all of the passage may be internally located within the shaft and/or the one of the pair of opposed end plates.

[0098] In some embodiments, the elongate body may include at least one passage extending axially through the body from the at least one expansion fluid inlet associated with either an externally accessible end of the shaft or one of the pair of opposed end plates at least partially towards the other end of the shaft or the other of the pair of the opposed ends plates. In such embodiments, the at least one passage may be in fluid communication with the expansion fluid receiving volume via one or more bleed passages extending in a substantially perpendicular direction relative to the at least one passage extending axially through the body.

[0099] The expansion fluid inlet may typically be located at an end of the shaft of the elongate body that is externally accessible through an outer surface of a connected end plate. The expansion fluid inlet is preferably adapted such that it is connectable to a source of the expansion fluid by a tube, pipe or hose. The expansion fluid inlet may be connectable to the tube, pipe or hose by suitable means. For example, the expansion fluid inlet may have a quick coupling or may be barbed for connecting the tube, pipe or hose. If barbed, an end of the tube, pipe or hose may be secured in place over the barbed inlet by a hose clamp or clip.

[00100] Depending on the expansion fluid, the source of the expansion fluid may include a pump or compressor, for example. For example, if the expansion fluid is a gas, the gas may be provided in a compressed form and be provided by a compressor or the like. Alternatively, if the expansion fluid is a liquid, the liquid may be provided in a container and be provided by a pump.

[00101] The expansion fluid may be supplied to the pipe plug device at any suitable pressure to expand the at least one expandable portion. For example, the expansion fluid may be supplied to the expansion fluid inlet at a pressure of between about 15 psi to about 900 psi, about 20 psi to about 900 psi, about 25 psi to about 900 psi, about 30 psi to about 900 psi, about 35 psi to about 900 psi, about 40 psi to about 900 psi, about 45 psi to about 900 psi, about 50 psi to about 900 psi, about 55 psi to about 900 psi, about 60 psi and about 900 psi, about 65 psi and about 900 psi, about 70 psi and about 900 psi, about 75 psi and about 900 psi, about 80 psi and about 900 psi, about 85 psi and about 900 psi, about 90 psi and about 900 psi, about 100 psi and about 900 psi, about 105 psi and about 900 psi, about 1 10 psi and about 900 psi, about 1 15 psi and about 900 psi, about 120 psi and about 900 psi, about 125 psi and about 900 psi, about 130 psi and about 900 psi, about 135 psi and about 900 psi, about 140 psi and about 900 psi, about 145 psi and about 900 psi or about 150 psi and about 900 psi.

[00102] In some embodiments, the device may further include an inlet valve to isolate the expandable portion in the expanded or rest state, for example. The inlet valve may be associated with the passage, such as, e.g., the expansion fluid inlet, or may be associated with the tube, pipe or hose connecting the device to the source of the expansion fluid.

[00103] Any suitable type of inlet valve may be used. Typically, the inlet valve will have a valve seat located within or associated with either the passage or the tube, pipe or hose connected to the expansion fluid inlet, a sealing member movable into or out of engagement with the valve seat, and an operable lever, handle or knob for moving the sealing member between open and closed positions. The valve may in the form of a tap that includes a sealing member that locates within a valve seat to block the passage when in the closed position and an operable knob for incrementally moving the sealing member.

[00104] In some embodiments, the device may include a bleed valve for releasing or removing the expansion fluid from the at least one expandable portion and enabling the expandable portion to return to its rest state. Again, the bleed valve may be associated with the passage, such as, e.g., the expansion fluid inlet, or may be associated with the tube, pipe or hose connecting the device to the source of the expansion fluid.

[00105] Any suitable type of bleed valve may be used. Typically, the bleed valve will have a valve seat located within or associated with either the passage or the tube, pipe or hose connected to the expansion fluid inlet, a sealing member movable into or out of engagement with the valve seat, and an operable lever, handle or knob for moving the sealing member between open and closed positions. The valve may in the form of a tap that includes a sealing member that locates within a valve seat to block the passage when in the closed position and an operable knob for incrementally moving the sealing member. [00106] In some embodiments, the device may include at least one attachment or tether point for attachment of an arm, tether or guide to the device to assist in the insertion and removal of the device into and from a pipe. The at least one attachment or tether point may be of any suitable size, shape and construction and may be located in any suitable location on the device. Generally, the at least one attachment or tether point may be located on an end plate, preferably the outer surface of the end plate.

[00107] In preferred embodiments, an attachment or tether point may be located on both end plates. For example, a leading end plate inserted first into a pipe may include an attachment or tether point for a guide, such as, e.g., a roller or wheel, and a trailing end plate may include an attachment or tether point for an arm or tether. Typically, the trailing end plate may include the expansion fluid inlet.

[00108] The attachment or tether point may preferably enable an arm, tether or guide to be releasably attached or tethered to the device. For example, the attachment or tether point may be in the form of a clip, loop or coupler.

[00109] In some embodiments, the device may include more than one expandable portion. For example, the device may include two, three, four, five, six, seven, eight, nine or even at least 10 expandable portions arranged in series along a length of the elongate body.

[001 10] In such embodiments, the expandable portions may be separated from one another by intermediate plates mounted along the shaft of the elongate body. Each intermediate plate may be of a similar construction to the end plates with the exception that both surfaces of the intermediate plate may include a sidewall for engaging and connecting with an adjacent open end of an expandable portion.

[001 1 1 ] In such embodiments, the passage may extend between the expansion inlet associated with one of the pair of opposed end pates and a plurality of expansion fluid outlets, each outlet being located on the shaft of the elongate body between adjacent plates. Again, the expansion fluid receiving volume of each expandable portion may be in fluid communication with the passage.

[001 12] In yet other embodiments, the system of the present invention may include more than one device tethered or coupled together in a serial arrangement or end plate-to-end plate arrangement. In such embodiments, two, three, four, five, six, seven, eight, nine or even 10 devices may be tethered or coupled together in a serial arrangement.

[001 13] In such embodiments, the devices may further be coupled together by at least one passage extending from the at least one expansion fluid inlet associated with a trailing device to a leading device. The at least one passage may be in fluid communication with the expansion fluid receiving volume of each device for expanding each respective expandable portion. In some such embodiments, the at least one passage may be in fluid communication with the expansion fluid receiving volume of each device via one or more bleed passages as previously described.

[001 14] In preferred such embodiments, the at least one passage may include one or more segments of pipe connecting the passages of adjacent devices. The pipe may preferably be a flexible meaning that the pipe may bend about 90° or more. Likewise, the pipe may be substantially resilient.

[001 15] In some embodiments, the system may further include at least one interlocking mechanism for interlocking adjacent devices in a substantially linear arrangement when being, or having been, axially inserted into a pipe. The inventors have found that it is necessary to interlock adjacent devices to prevent twisting or rotation of the devices relative to one another, which can otherwise cause bends, twists or kinks in the at least one passage, or segments of the at least one passage, extending between the devices.

[001 16] The interlocking mechanism may be of any suitable size, shape and form for interlocking adjacent devices in any suitable way.

[001 17] In preferred embodiments, the interlocking mechanism may be in the form of a linear actuator for extending and retracting a locking pin between an interlocking position and a retracted position, respectively. In the interlocking position, the locking pin may extend from an end plate of a first device at least partially into an opening defined in an adjacent end plate of a second device. In the retracted position, the locking pin may be at least partially retracted into the first device such that it is at least retracted clear of the second device and thus the second device is able to pivot relative to the first device.

[001 18] In some such embodiments, movement of the locking pin between the positions may be pneumatically or hydraulically driven, for example. In other such embodiments, movement of the locking pin may be driven by at least one solenoid, such as, e.g., an electromechanical solenoid.

[001 19] Preferably, movement of the locking pin may be driven by the expansion fluid. For example, the locking pin may be driven to the locking position when expansion fluid is supplied to the at least one expandable portion of each device. Likewise, the locking pin may be moved or returned to the retracted position when the expansion fluid is bled from each device. [00120] In some embodiments, the interlocking mechanism may further include one or more biasing mechanisms so that movement of the locking pin to the locking position works against the force of the biasing mechanism and so that the locking pin moves to the retracted position under the force of the biasing mechanism. The biasing mechanism may include one or more springs, such as, e.g., coil or leaf springs. Of course, a person skilled in the art will appreciate that other types of biasing mechanisms, such as, e.g., magnets or magnetized elements and the like may be used.

[00121 ] In preferred embodiments, each device may include an interlocking mechanism in the form of an interlocking passage extending axially through the elongate body, preferably parallel with the at least one passage.

[00122] The interlocking passage may at least partially house the locking pin.

[00123] The interlocking passage may include an inlet port at one of the opposed end plates and an outlet port at the other of the opposed end plates. The inlet port may be configured to at least partially receive the locking pin from an adjacent device. The outlet port may be configured to convey the locking pin of the device to the inlet port of an adjacent device.

[00124] In such embodiments, the interlocking passage may be in fluid communication with the at least one passage conveying the expansion fluid for driving movement of the locking pin.

[00125] According to a third aspect of the present invention, there is provided a method of isolating a portion of a pipe conveying a fluid, said method including:

axially inserting the pipe plug device of the first aspect into the pipe; and supplying the expansion fluid into the at least one expandable portion of the device for expanding said portion to sealingly engage with an inner surface of the pipe and stop the flow of fluid thereby isolating the portion of the pipe.

[00126] The method may include one or more characteristics or features of the pipe plug device and system as hereinbefore described.

[00127] The method may optionally include an initial step of fastening a fitting to the pipe either upstream or downstream from a location along the pipe where the pipe plug device is to be inserted. The fitting may include a saddle or a tee fitting.

[00128] The method may further optionally include cutting a hole in a side of the pipe via a fitting with a hole saw, for example.

[00129] The axially inserting may include coupling the pipe plug device to an arm for insertion into the pipe via the fitting. The axially inserting may further include coupling a guide to the pipe plug device to assist in guiding the pipe plug device along the pipe.

[00130] The arm may be an articulated arm configured to be attached, tethered or coupled to an end of the device, preferably releasably.

[00131] The guide may include a wheel or roller configured to be attached, tethered or coupled to an end of the device, preferably releasably. Typically, the guide may be coupled to an opposite end of the device than the arm, preferably via at least one articulation.

[00132] In other embodiments, the arm may be at least a portion of the tube, pipe or hose connecting the device to the source of the expansion fluid. The at least a portion of the tube, pipe or hose may be stiffened to assist in the insertion and removal of the device from a pipe.

[00133] The at least a portion of the tube, pipe or hose may be stiffened in any suitable way. For example, in some such embodiments, the at least a portion may include a thickened wall or coating. In other such embodiments, the at least a portion may include a supporting portion, such as, e.g., a brace to at least partially stiffen the portion of the tube, pipe or hose.

[00134] The axially inserting may preferably include inserting the pipe plug device upstream or downstream from the fitting relative to the flow of fluid within the pipe.

[00135] The supplying the expansion fluid may commence once the pipe plug device is positioned in a desired location.

[00136] In some embodiments, the supplying may include pumping a liquid expansion fluid into the expandable portion of the device via the expansion inlet valve until the expandable portion is in the expanded state and the flow of fluid in the pipe is stopped.

[00137] In other embodiments, the supplying may include supplying a gaseous expansion fluid into the expandable portion with a compressor via the expansion inlet valve until the expandable portion is in the expanded state and the flow of fluid in the pipe is stopped.

[00138] In some embodiments, the supplying may further include using an inlet valve to isolate the expandable portion in the expanded state.

[00139] To remove the pipe plug device, the expansion fluid may be released or removed from the expandable portion so that the expandable portion may return to the rest state and the device may be removed via the fitting.

[00140] The expansion fluid may be released or removed in any suitable way. [00141 ] For example, in some embodiments, the expansion fluid may be bled by disconnecting the pipe, tube or hose from the source of the expansion fluid so that the expansion fluid may then bleed from the disconnected end.

[00142] In other embodiments, the expansion fluid may be bled via a bleed valve associated with the expansion fluid inlet or the pipe, tube or hose connecting the device to the source of the expansion fluid.

[00143] Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention.

[00144] The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

BRIEF DESCRIPTION OF DRAWINGS

[00145] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of Invention in any way. The Detailed Description will make reference to a number of drawings as follows:

[00146] Figure 1 is a photograph showing a side view of a pipe plug device according to an embodiment of the present invention;

[00147] Figure 2 is a schematic showing a sectional side view of a pipe plug device according to the embodiment shown in Figure 1 ;

[00148] Figures 3A to 3C are schematics showing various views and parts of a pipe plug device according to another embodiment of the present invention;

[00149] Figure 4 is a schematic showing a side view of two pipe plug devices as shown in Figures 3A to 3C coupled together in a serial arrangement for stopping a flow of fluid in a pipe;

[00150] Figure 5 is a flowchart showing steps in a method of installing and removing the pipe plug device as shown in Figures 1 , 2, 3A to 3C and 4; and

[00151 ] Figures 6A to 6E are a series of schematics showing sectional side views of the pipe plug device as shown in Figures 1 and 2 being installed according to the method of Figure 5. DETAILED DESCRIPTION

[00152] Figures 1 , 2, 3A, 3B and 3C show a pipe plug device (100) according to embodiments of the present invention.

[00153] Referring to Figures 1 and 2, in this first embodiment, the pipe plug device (100) includes an elongate body (1 10) configured to be axially inserted into a pipe via a connection into the pipe, such as, e.g., a saddle or tee fitting. The body (1 10) includes a pair of opposed end plates (120) and a shaft (130; visible only in Figure 2) extending longitudinally therebetween. The device (100) further includes an expandable portion (140) located about an outer periphery of the body (1 10) between the opposed end plates (120). The expandable portion (140) is configured to receive an expansion fluid and expand to sealingly engage with an inner surface of a pipe and stop the flow of a fluid in the pipe.

[00154] Referring to Figure 1 , the elongate body (1 10) is formed from a durable and substantially rigid material, such as, e.g., metal.

[00155] The end plates (120) each have a substantially circular profile shape and are of a solid construction. Each end plate (120) has opposed surfaces extending substantially parallel to one another, including an outer surface (122) and an opposed inner surface (124). The opposed surfaces are interconnected by at least one side edge (126).

[00156] Referring to Figure 2, each end plate (120) further includes a rim (128) and a sidewall

(127) extending inwards from, or away from, the inner surface (124) to the rim (128). The rim

(128) extends along a distal portion or outer edge of the sidewall (127). The sidewall (127) extends orthogonally inwards from each end plate (120) at least partially towards the opposed end plate (120).

[00157] The shaft (130) has a substantially cylindrical shape with two opposed ends (132) and at least one curved sidewall extending therebetween. The shaft (130) is of solid construction.

[00158] As shown, the shaft (130) includes a stepped central portion (134) having a greater diameter than the outer end portions (136). The stepped central portion (134) assists in retaining a clamping plate (210) near each outer end portion (136), which will be discussed in detail later.

[00159] Each end plate (120) is threadingly connected to an end (132) of the shaft (130) such that the end plate (120) is centrally aligned relative to the shaft (130). In particular, each end (132) of the shaft (130) includes a threaded protrusion configured to threadingly engage with a corresponding opening (121 ) defined in a central portion of the end plate (120). [00160] The expandable portion (140) is formed from a resiliently deformable material or materials, such as, e.g., rubber or plastic material or materials. Moreover, the material or materials is substantially impermeable so as to contain the expansion fluid.

[00161 ] The expandable portion (140) defines an expansion fluid receiving volume (148) about the shaft (130) and the inner surfaces (124) of the end plates (120) of the elongate body (1 10).

[00162] As shown, the expandable portion (140) is in the form of an open-ended cylindrical sleeve configured to be fitted about the shaft (130) of the elongate body (1 10). The expandable portion (140) includes opposed open ends (142) and a cylindrical membrane (144) extending therebetween. Each of the opposed open ends (142) is connectable with an inner surface (124) of an adjacent end plate (120) to sealingly contain the expansion fluid when provided.

[00163] Each of the opposed open ends (142) of the expandable portion (140) is defined by a shaped collar (146) formed from an annular portion of the expandable portion (140) located adjacent to and around a periphery of the open end (142).

[00164] The membrane (144) is configured to transition between a resting state (shown) and an expanded state.

[00165] In the shown resting state, the membrane (144) of the expandable portion (140) has a cross sectional width less than or the same as the maximum width of the end plates (120) of the elongate body (1 10).

[00166] In the expanded state, the membrane (144) will have a cross sectional width greater than the maximum width of the end plates (120) of the elongate body (1 10).

[00167] In the resting state, the expandable portion (140) has a shaped resting shape characterised by a pair of corrugations (148) extending about the membrane (144) in a lateral direction relative to a longitudinal length of the membrane (144) extending between the opposed open ends (142). The corrugations (148) are in the form of indentations or depressions extending about the expandable portion (140).

[00168] Advantageously, the corrugations (148) at least partially strengthen the membrane (144) when the expandable portion (140) is in the resting state. The corrugations (148) also advantageously increase the surface area of the membrane (144) and thereby increase the size that the expandable portion (140) can expand when in the expanded state.

[00169] The expandable portion (140) returns to the shaped resting shape when the expansion fluid has been released or removed.

[00170] As indicated above, each of the opposed open ends (142) of the expandable portion (140) is connectable with the inner surface (124) of an adjacent end plate (120) to sealingly contain the expansion fluid when provided.

[00171 ] The shaped collar (146) of the expandable portion (140) is connectable to the inner surface of the end plate (120) by way of an interference fit-type connection.

[00172] In particular, the inner surface (124), the sidewall (127) and the rim (128) of each end plate (120) defines a female formation configured to at least partially receive and be coupled with a male formation defined by the annular portion and outer edge of the shaped collar (146) of the expandable portion (140).

[00173] As shown, each shaped collar (146) of the expandable portion (140) also includes a recessed outer edge (149) for receiving the rim (128) and sidewall (127) of the adjacent end plate (120) such that the membrane (144) of the expandable portion (140) lies substantially flush with the sidewall (127) of each end plate (120).

[00174] As mentioned earlier, the device (100) further includes a pair of clamping plates (210) each for clamping a shaped collar (146) of the expandable portion (140) against an adjacent end plate (120) of the elongate body (1 10).

[00175] The clamping plates (210) have a substantially circular profile shape and are of solid construction. Each clamping plate (210) has opposed surfaces extending substantially parallel to one another, including a clamping surface (212) and an opposed outer surface (214). The opposed surfaces are interconnected by at least one outer edge (216).

[00176] Each clamping plate (210) is slidably mounted over an outer end portion (136) of the shaft (130). Specifically, each clamping plate (210) includes a central aperture (138) configured to receive at least a portion of the end portion (136) of the shaft (130) therethrough in a sliding arrangement. In use, each clamping plate (210) slides and clamps an adjacent shaped collar (146) of the expandable portion (140) against an adjacent end plate (120) when the expansion fluid receiving volume (148) is filled and pressurised with the expansion fluid.

[00177] To ensure each clamping plate (210) slides and clamps an adjacent shaped collar (146) against an adjacent end plate (120) when pressurised, the central aperture (138) of each clamping plate (210) further includes two O-rings (139). The O-rings (139) are at least partially seated in corresponding grooves arranged in series within the central aperture (138). The O- rings assist by forming an at least partial seal against the portion of the end portion (136) of the shaft (130) slidingly received through the aperture (138) to thereby at least partially prevent leakage of expansion fluid through the aperture (138).

[00178] As indicated above, the shaft (130) includes a stepped central portion (134) having a greater diameter than the outer end portions (136). The stepped central portion (134) is configured to prevent the clamping plates (210) associated with each end (132) of the shaft (130) from sliding over to an opposite end (132) of the shaft (130).

[00179] The expansion fluid can be any suitable fluid able to be supplied into the pipe plug device (100) under pressure and expand the expandable portion (140). The expansion fluid can be a liquid or gas. For example, the expansion fluid can include water, oil (hydraulic oil), gas, nitrogen gas, or air.

[00180] In order to receive the expansion fluid, the body (1 10) includes a passage (310) extending from an expansion fluid inlet (312) associated with an end (132) of the shaft (130) that extends through an outer surface (122) of an end plate (120) and an expansion fluid outlet (314) located on the shaft (130) between the two opposed ends (132) of the shaft (130). The expansion fluid receiving volume (148) is in fluid communication with the passage (310).

[00181 ] The expansion fluid inlet (312) is adapted such that it is connectable to a source of the expansion fluid by a tube, pipe or hose. The expansion fluid inlet (312) is connectable to the tube, pipe or hose by a quick coupling.

[00182] Depending on the expansion fluid, the source of the expansion fluid may include a pump or compressor, for example. For example, if the expansion fluid is a gas, the gas may be provided in a compressed form and be provided by a compressor or the like. Alternatively, if the expansion fluid is a liquid, the liquid may be provided in a container and be provided by a pump.

[00183] The expansion fluid is supplied to the pipe plug device (100) at a suitable pressure to expand the expandable portion (140).

[00184] Figures 3A to 3C show a second embodiment of the pipe plug device (100). For convenience, features that are similar or correspond to features of the first embodiment will be referenced with the same reference numerals.

[00185] In this second embodiment, the pipe plug device (100) again includes an elongate body (1 10) configured to be axially inserted into a pipe via a connection into the pipe, such as, e.g., a saddle or tee fitting.

[00186] The body (1 10) again includes a pair of opposed end plates (120; not shown in Figure 3C) and a shaft (130; shown in Figures 3B and 3C) extending longitudinally therebetween. The device (100) again further includes an expandable portion (140; not shown in Figure 3C) located about an outer periphery of the body (1 10) between the opposed end plates (120; not shown in Figure 3C). The expandable portion (140; not shown in Figure 3C) is configured to receive an expansion fluid and expand to sealingly engage with an inner surface of a pipe and stop the flow of a fluid in the pipe.

[00187] Referring to Figure 3B, each end plate (120) is threadingly connected to an end (132) of the shaft (130) such that the end plate (120) is centrally aligned relative to the shaft (130). In particular, each end (132) of the shaft (130) includes a threaded protrusion configured to threadingly engage with a corresponding opening (121 ) defined in a central portion of the end plate (120).

[00188] The expandable portion (140) is formed from a resiliency deformable material or materials, such as, e.g., rubber or plastic material or materials. Moreover, the material or materials is substantially impermeable so as to contain the expansion fluid.

[00189] The expandable portion (140) defines an expansion fluid receiving volume (148) about the shaft (130) of the elongate body (1 10). The expandable portion (140) is moulded about the shaft (130) and as shown is partially clamped between the shaft (130) and each end plate (120). Features shown at the top of Figures 3A and 3B are moulding artefacts (X) that do not contribute to the working of the device (100).

[00190] The expandable portion (140) includes opposed open ends (142) and a cylindrical membrane (144) extending therebetween. Each of the opposed open ends (142) of the expandable portion (140) is defined by a shaped collar (146) formed from an annular portion of the expandable portion (140) located adjacent to and around a periphery of the open end (142).

[00191 ] The membrane (144) is configured to transition between a resting state (shown) and an expanded state.

[00192] In the shown resting state, the membrane (144) of the expandable portion (140) has a cross sectional width less than or the same as the maximum width of the end plates (120) of the elongate body (1 10) with the exception of the moulding artefacts (X).

[00193] In the expanded state, the membrane (144) will have a cross sectional width greater than the maximum width of the end plates (120) of the elongate body (1 10).

[00194] The expandable portion (140) returns to the resting shape when the expansion fluid has been released or removed. [00195] As discussed, the shaped collar (146) of the expandable portion (140) is at least partially clamped between the end plates (120) and the shaft (130). In particular, the shaft (130) includes a stepped central portion (134) having a greater diameter than the outer end portions (136). The stepped central portion (134) is configured to clamp the shaped collar (146) of the expandable portion (140) against an adjacent end plate (120).

[00196] In order to receive the expansion fluid, the body (1 10) includes a passage (310) extending from an expansion fluid inlet (312) associated with an end (132) of the shaft (130) that extends through an outer surface (122) of an end plate (120) and an expansion fluid outlet (314) located on the shaft (130). The expansion fluid out (314) is fluid communication with the passage (310) via a pair of bleed passages (316) that extend perpendicular relative to the passage (310) in a direction extending laterally across the shaft (130). The expansion fluid receiving volume (148) is in fluid communication with the passage (310) via the pair of bleed passages (316).

[00197] The expansion fluid inlet (312) is adapted such that it is connectable to a source of the expansion fluid by a tube, pipe or hose. The expansion fluid inlet (312) is connectable to the tube, pipe or hose by a quick coupling.

[00198] Referring briefly to Figure 4, this figure shows an embodiment of a system (1000) of the present invention in which at least two devices (100) are coupled together and arranged in a serial arrangement.

[00199] As shown, the two devices (100) are coupled together by a coupler (1010) which enables the devices (100) to pivot relative to one another.

[00200] The leading device (100A) further includes a roller (430) coupled to a leading end plate (120A) of the device (100A) to assist in guiding the two devices (100) to a desired location within a pipe.

[00201 ] The trailing device (100B) further includes an articulated arm (420) coupled to a trailing end plate (120B) of the device (100B) to enable positioning of the two devices (100) within the pipe.

[00202] The articulated arm (420) is coupled to the same end plate (120) as the tube, pipe or hose (not visible) connecting the devices (100) to the source of the expansion fluid.

[00203] Referring back to Figure 3C, in such embodiments of the system (1000; not shown) each device (100) further includes an interlocking mechanism (340) for interlocking adjacent devices (100) in a substantially linear arrangement when being axially inserted into a pipe. [00204] The interlocking mechanism (340) is a linear actuator including an interlocking passage (342) extending axially through the body (1 10), parallel to the passage (310).

[00205] The interlocking passage (342) houses a locking pin (not shown) and coil spring (not shown). The locking pin (not shown) is slidably moveable between a locking position in which the pin extends forward from a first device (100) into a second device (100; not shown) and a retracted position in which the pin is at least partially retracted into the first device (100) at least clear of the second device (100; not shown) so that the second device (100; not shown) is pivotable relative to the first device (100).

[00206] In use, movement of the locking pin (not shown) to the locking position is driven against the force of the coil spring (not shown) by the expansion fluid with the passage (342) being in fluid communication with the passage (310). Conversely, the locking pin (not shown) is moveable to the retracted position at least partially under the force of the coil spring (not shown) when the expansion fluid is bled from each device (100).

[00207] A method (500) of using the pipe plug device (100) as shown in Figures 6A to 6E is now described in detail with reference to Figure 5.

[00208] At step 510, the method (500) includes fastening a fitting (410) to the pipe (900) via which the pipe plug device (100) is to be inserted. The fitting (410) includes an inlet through which tools, including the device (100), can be inserted and operated.

[00209] At step 520, a hole saw is inserted into and operated within the fitting (410) to cut a hole in a side of the pipe (900).

[00210] At step 530, the pipe plug device (100) is axially inserted into the pipe (900) via the fitting (410) in a direction either upstream or downstream from the fitting (410).

[0021 1 ] With particular reference to Figures 6A to 6D, the pipe plug device (100) is axially inserted into the pipe with an articulated arm (420) via the fitting (410).

[00212] In some embodiments, the arm (420) is coupled to an end plate (120) of the device (100). In other embodiments, the arm (420) is coupled to an end (132) of the shaft (130). In either embodiment, the arm (420) is coupled to a same side of the device (100) as the tube, pipe or hose (not visible) connecting the device (100) to the source of the expansion fluid.

[00213] To assist in guiding the device (100) to a desired location upstream from the fitting (410), a roller (430) is coupled to an end plate (120) of the device (100) at an opposite end of the device (100) to the arm (420). The roller (430) is configured to roll against an inner surface of the pipe (900). The roller (430) is coupled to the end plate (120) of the device (100) via at least one articulation enabling the device (100) and roller (430) to maintain a correct (axial) orientation when inserted via the fitting (410) into the pipe (900).

[00214] At step 540, once the pipe plug device (100) is positioned in a desired location in the pipe (900), either upstream or downstream from the fitting (410), the expansion fluid is supplied, via either pump or compressor depending on the type of expansion fluid used, to the expandable portion (140; labelled in Figures 6A and 6E) of the device (100). The expansion fluid is delivered via the tube, pipe or hose connected to the expansion fluid inlet (312).

[00215] The expansion fluid is received within the expansion fluid receiving volume (148) where it causes the expandable portion (140; labelled in Figures 6A and 6E) to expand. Best shown in Figure 6E, expansion fluid is continuously supplied until the expandable portion (140) sealingly engages with or against an inner surface of the pipe (900) and stops the flow of fluid within the pipe (900).

[00216] The portion of pipe (900) downstream from the device (100) and fitting (410) is now isolated.

[00217] At step 550, once all necessary work has been completed on the portion of pipe (900) downstream from the device (100) and the fitting (410), the flow of fluid can be restored through the pipe (900). This is achieved by releasing the expansion fluid from the expandable portion (140; labelled in Figures 6A and 6E) so that the expandable portion (140) contracts to its shaped resting shape as shown in Figures 6A to 6D.

[00218] At step 560, the pipe plug device (100) is removed from the pipe (900) via the fitting (410) and the inlet is closed with a closure element, such as, e.g., a mechanical plug or valve.

[00219] In the present specification and claims (if any), the word “comprising” and its derivatives including “comprises” and “comprise” include each of the stated integers but does not exclude the inclusion of one or more further integers.

[00220] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations. [00221] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

Claims

1 . A pipe plug device for stopping a flow of fluid in a pipe, said device including:

2. The device of claim 1 , wherein the elongate body further includes a shaft extending between the opposed end plates.

3. The device of claim 1 or claim 2, wherein the at least one expandable portion includes a sleeve connectable to the elongate body to sealingly contain the expansion fluid and be expandable.

4. The device of claim 2 or claim 3, wherein the at least one expandable portion includes opposed open ends and at least one membrane extending therebetween, the opposed open ends being connectable about opposed ends of the shaft of the elongate body.

5. The device of any one of claims 1 to 4, wherein the at least one expandable portion transitions from a resting state to an expanded state when the expansion fluid is supplied, and wherein the at least one expandable portion returns to the resting state when the expansion fluid is released or removed.

6. The device of claim 5, wherein the at least one expandable portion includes a shaped resting shape and the at least one expandable portion returns to the shaped resting shape when the expansion fluid is released or removed.

7. The device of any one of claims 1 to 6, wherein of the at least one expandable portion includes one or more corrugations.

8. The device of any one of claims 1 to 7, wherein an outer surface of the at least one expandable portion includes one or more protrusions protruding out from an outer surface to assist in forming a substantially water/gas tight seal with the inner surface of the pipe.

9. The device of any one of claims 2 to 8, wherein the elongate body includes at least one passage extending axially through body between at least one expansion fluid inlet associated with an externally accessible end of the body and at least one expansion fluid outlet in fluid communication with the at least one expandable portion.

10. The device of claim 9, wherein the expansion fluid is supplied by a tube, pipe or hose connectable to a source of the expansion fluid and the at least one expansion fluid inlet.

1 1 . The device of any one of claims 1 to 10, further including an isolation valve for isolating the at least one expandable portion in an expanded or rest state.

12. The device of any one of claims 1 to 1 1 , further including a bleed valve for releasing or removing the expansion fluid from the at least one expandable portion and enabling the expandable portion to return to its rest state.

13. The device of any one of claims 1 to 12, further including an attachment or tether point on one or both end plates for attachment or tether of one or more guides or arms for positioning of the device within the pipe.

14. A pipe isolation system for stopping a flow of fluid in a pipe, said system including: at least one pipe plug device configured to be axially inserted into the pipe, said device including:

a connection into the pipe through which the device is inserted; and

15. The system of claim 14, wherein the system includes at least two devices tethered or coupled together in a serial arrangement such that the devices are able to pivot relative to one another.

16. The system of claim 15, wherein the at least two devices are connected by at least one passage extending from at least one expansion fluid inlet associated with a trailing said device to a leading said device, the at least one passage being in fluid communication with the at least one expandable portion of each device for expanding said portion.

17. The system of claim 16, wherein the leading said device includes a guide and the trailing said device includes an arm for positioning the at least two devices within the pipe.

18. The system of any one of claims 15 to 17, further including at least one interlocking mechanism for interlocking the at least two devices in a substantially linear arrangement when inserted into the pipe to prevent at least partial rotation of the devices relative to one another.

19. The system of any one of claims 14 to 18, wherein the source of the expansion fluid includes a pump or a compressor.

20. The system of any one of claims 14 to 19, wherein the connection into the pipe is a saddle or tee fitting.

21 . A method of isolating a portion of a pipe conveying a fluid, said method including:

axially inserting the pipe plug device of any one of claims 1 to 13 into the pipe; and supplying the expansion fluid into the at least one expandable portion of the device for expanding said portion to sealingly engage with an inner surface of the pipe and stop a flow of fluid thereby isolating the portion of the pipe.

22. The method of claim 21 , wherein the axially inserting further includes coupling a guide and an arm to the device to assist in positioning the device within the pipe.

23. The method of claim 21 or claim 22, wherein the axially inserting includes inserting the device upstream or downstream from a fitting used to insert the device within the pipe.

24. The method of any one of claims 21 to 23, wherein the supplying includes pumping a liquid expansion fluid into the at least one expandable portion until the expandable portion sealingly engages with the inner surface of the pipe and stops the flow of fluid.

25. The method of any one of claims 21 to 23, wherein the supplying includes supplying a gaseous expansion fluid into the at least one expandable portion until the expandable portion sealingly engages with the inner surface of the pipe and stop the flow of fluid.