SYSTEM AND METHOD FOR LAYING CABLES AND THE LIKE THROUGH FLUID PIPES

Abstract

A pipe (100) comprises a first connector fitting (102) and a second connector fitting (104) downstream of the first. The fluid pressure within the pipe (100) is substantially equalised to the air pressure within the first connector fitting (102). Then a draw wire (4), fitted with a sail structure (6) is inserted through the first connector fitting (102). Fluid flow within the pipe (100) acts upon the sail structure 6 to move the draw wire (4) along the pipe (100) in towards the second connector fitting (104) where an extraction member (108) is inserted. The extraction member (108) is used to withdraw the draw wire (14) through the second connector fitting (104). The draw wire (4) is attached to a first end of a micro-duct (110) and thus a pulling mechanism (114) can act on the draw wire 4 to introduce the micro-duct (110) into the pipe (100) between the connector fittings (102, 104).

Claims

1-39. (canceled)

40. A method of laying one or more elongate flexible members through a fluid pipe comprising the steps of: a) inserting a first end of draw wire into the fluid pipe through a first opening in the fluid pipe; b) allowing the draw wire to travel along the pipe under the influence of the fluid flow through the pipe; c) withdrawing the first end of the draw wire from the pipe through a second opening in the pipe such that the first end of the draw wire is located at the second opening, outside of the pipe; a second end of the draw wire which is located at the first aperture, outside of the pipe; and an intermediary portion of the draw wire is located between the first and second ends of the wire within the pipe; d) attaching a first end of the or each elongate flexible member to the second end of the draw wire; and e) moving the draw wire through the pipe in a direction from the first opening towards the second opening to transfer the or each elongate flexible member through the pipe and subsequently out of the pipe through the second opening such that the or each elongate flexible member has a first end which is located at the second opening, outside of the pipe; an intermediary portion located within the pipe between the first and second openings; and the remainder of the or each elongate member is located at the first opening, outside of the pipe.

41. A method as claimed in claim 40 wherein the draw wire is provided with a sail structure attached to or integrally formed with the draw wire and positioned at an angle to the direction of fluid flow along the pipe, and the method comprises allowing the draw wire to move along the length of the pipe by means of the fluid within the pipe acting on said sail structure.

42. A method as claimed in claim 41 comprising collapsing the sail structure from an expanded configuration to a collapsed configuration in order to insert or remove it from the pipe through the first and/or second openings.

43. A method as claimed in claim 40 wherein withdrawing the first end of the draw wire from within the pipe through the second opening is achieved under the operation of a withdrawal means, the withdrawal means comprising an extraction member and the method comprises inserting the extraction member through the second opening and subsequently engaging a portion of the draw wire to connect therewith for withdrawal of the first end of the draw wire from the interior of the pipe.

44. A method as claimed in claim 40 further comprising installing one or more connector fittings on the pipe, each connector fitting providing the first and/or second openings in the pipe.

45. A method as claimed in claim 44 wherein the or each connector fitting comprises a pressure chamber and the method further comprises utilising the or each pressure chamber to equalise the fluid pressure within the pipe to the air pressure within the connector fitting.

46. A method of claim 40 wherein the method comprises monitoring the position of the draw wire as it is allowed to move along the length of the fluid pipe.

47. A method as claimed in claim 40 wherein at least one of the one or more elongate flexible members comprises a micro-duct, and the method further comprises the step of introducing at least one cable into the or each micro-duct subsequent to step e).

48. A sail structure for use in the method of claim 40 comprising a surface attached to or integrally formed with the draw wire and which in use is positioned at an angle to the direction of fluid flow along the pipe, wherein the sail structure is moveable between a collapsed configuration and an expanded configuration.

49. A structure as claimed in claim 48 wherein the sail structure is retained in its expanded configuration under the operation of a biasing means.

50. An extraction member for use in the method as claimed in claim 40 comprising a body which is operable in use to be inserted through the second opening in the pipe, the body having a surface thereon operable to engage a portion of the draw wire and/or sail structure for subsequent withdrawal of the first end of the draw wire from within the interior of the pipe.

51. An extraction member as claimed in claim 50 wherein the surface of the member comprises a magnet or series of magnets and the draw wire and/or sail structure comprises a portion which is formed of a magnetic material.

52. An extraction member as claimed in claim 50 additionally comprising a means to view along the length of the pipe when it is inserted through the second opening; or additionally comprising an illumination means.

53. An extraction member as claimed in claim 52 comprising at least one bore dimensioned to receive either the viewing means or the illumination means.

54. A connector fitting for use in a method as claimed in claim 40 comprising an attachment means adapted to attach to a surface of the fluid pipe about an opening within the pipe; and a sealing means for providing a watertight seal around the opening.

55. A connector fitting as claimed in claim 54 operable in use to allow for the introduction or removal of a draw wire and/or one or more elongate flexible members into or out of the interior of the pipe through the opening in the pipe, wherein the sealing means is operable to maintain the watertight seal once the draw wire and/or one or more elongate flexible members have been introduced/removed from the pipe, and/or during the introduction or removal of the draw wire and/or one or more elongate flexible members.

56. A connector fitting as claimed in claim 55 additionally comprising a pressure chamber, wherein the pressure chamber is operable in use to equalise the fluid pressure within the pipe to the air pressure within the connector fitting.

57. A kit of parts for performing the method of laying one or more elongate flexible members through a fluid pipe as claimed in claim 40 comprising; a sail structure comprising a surface attached to or integrally formed with the draw wire and which in use is positioned at an angle to the direction of fluid flow along the pipe, wherein the sail structure is moveable between a collapsed configuration and an expanded configuration; and a draw wire.

58. A kit of parts as claimed in claim 57 further comprising a means to withdraw the first end of the draw wire from within the pipe at the second opening of a pipe, in use, wherein the withdrawal means comprises an extraction member, said extraction member comprising a body which is operable in use to be inserted through the second opening in the pipe, the body having a surface thereon operable to engage a portion of the draw wire and/or sail structure for subsequent withdrawal of the first end of the draw wire from within the interior of the pipe.

59. A kit of parts as claimed in claim 58 further comprising an insertion mechanism, wherein the insertion mechanism comprises a transmitter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0069] In order that the invention may be more clearly understood an embodiment thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

[0070] FIG. 1 is a schematic side cross-sectional view of a section of a system in accordance with the second aspect of the present invention;

[0071] FIG. 2A is a schematic side cross-sectional view of the section of the system of FIG. 1 with the sail structure in a collapsed configuration;

[0072] FIG. 2B is a schematic end view of the section of the collapsed configuration of the sail structure of FIG. 2A;

[0073] FIGS. 3A-3D are a series of schematic side cross-sectional views of a pipe illustrating the method in accordance with the first aspect of the present invention;

[0074] FIGS. 4A-6 are cross-sectional views of an embodiment of an extraction member in accordance with an aspect of the present invention;

[0075] FIGS. 7A-7B are schematic side cross-sectional views of embodiments of the system of the present invention provided with a sterilisation chamber;

[0076] FIGS. 8A-8B are schematic side cross-sectional views of embodiments of the system of the present invention provided with an alternative form of sterilisation chamber;

[0077] FIG. 9 is a schematic side cross-sectional view of a further embodiment of the system of the present invention;

[0078] FIGS. 10-12 are side cross-sectional views of parts of an embodiment of a pressure chamber for use in a system in accordance with an aspect of the present invention; and

[0079] FIGS. 13A-13B are cross-sectional views of an embodiment of a connector fitting for use in a system in accordance with an aspect of the present invention.

[0080] FIG. 1 illustrates a section of a system 2 in accordance with an aspect of the present invention which includes a draw wire 4 and a sail structure 6. The system 2 further includes an annular stiffening ring 8, a first set of supporting arms 10 and a second set of supporting arms 12. In addition, the system 2 includes a means for extraction of the draw line 4 during operation in the form of magnetic end cap 14, a transmitter in the form of a micro-sonde 16 and a floatation ball 18.

[0081] As shown in FIG. 1, the sail structure 6 is constructed and arranged such that it is arranged in a substantially conical shape. At the apex of the conical shaped structure 6 there is provided an aperture 20, the purpose of which will be described herein below.

[0082] The sail structure 6 is shown as being connected to each of the supporting arms making up the first set of supporting arms 10, which are configured such that they have a complimentary shape to the sail structure 6. To achieve this, each of the supporting arms are connected at a first end to the other supporting arms making up the first set 10, and are connected at a second end to the annular stiffening ring 8. The result of such a configuration is that the sail structure 6 defines a hollow conical shape having an open base which is defined by the annular stiffening ring 8. The sail structure 6 therefore provides a structure which may be acted upon by fluid flow, in use.

[0083] The second set of supporting arms 12 are constructed and arranged in a similar fashion to the first set 10 as described above, with each of the supporting arms being connected at a first end to the other supporting arms making up the second set 12, and are connected at a second end to the annular stiffening ring 8. However, the sail structure 6 is not connected to the second set of supporting arms 12.

[0084] At a first end of the draw wire 4, on the left hand side of the sail structure 6 in the orientation shown in FIG. 1, the illustrated system 2 includes the magnetic end cap 14. This end cap 14 comprises part of an extraction mechanism which will be described herinbelow. In addition, the first end of the draw wire 4 includes the floatation ball 18 which aids the buoyancy of the system within the fluid flowing through a relevant pipe, in use. However, the use of floatation ball 18 is optional and will be dependent on the buoyancy of the system 2 as a whole which may differ depending on the components which it comprises. Likewise, more floatation balls may be used at other points along the draw wire 4 if necessary. On the opposing side of the sail structure 6, the draw wire 4 includes the micro-sonde 16.

[0085] The operational use of a system 2 which includes the section of the system illustrated in FIG. 1 will now be described with additional reference to FIGS. 2, 3A, 3B, 3C and 3D.

[0086] FIG. 3A shows a pipe 100 through which one or more elongate flexible members are placed using a method in accordance with the present invention. The pipe 100 may be any fluid pipe. As shown in FIG. 3A, the pipe 100 comprises a first connector fitting 102 at a first end of the pipe, and a second connector fitting 104 at a second end of the pipe which is downstream of the first. In some embodiments of the invention, the method may comprise installing the first and/or second connector fittings 102, 104 in position.

[0087] Initially, the fluid pressure within the pipe 100 is substantially equalised to the air pressure within the first connector fitting 102. If this step is not taken, fluid could be expelled from the pipe under pressure. This is at least undesirable and may be dangerous. This balancing of pressures may be performed using a pressure chamber which in some embodiments forms part of the first connector fitting 102. Alternatively, the pressure chamber may be an additional component (See FIGS. 10 to 12). It is noted that a similar procedure is undertaken at the second connector fitting 104 in order to access the interior of the pipe 100, when required.

[0088] Subsequent to balancing the pressures, the draw wire 4 is inserted through an opening (not shown) within the first connector fitting 102. The opening is dimensioned to allow the magnetic end cap 14, micro-sonde 16, first and second sets of supporting arms 10, 12, stiffening ring 8 and sail structure 6 to be passed therethrough.

[0089] In the illustrated embodiment the sail structure 6, stiffening ring 8 and sets of supporting arms 10, 12 are somewhat wider than the opening. However, to overcome this issue, the sail structure 6 is operable to be collapsed under the operation of the sets of supporting arms 10, 12 and stiffening ring 8 when passing through the opening.

[0090] To achieve this, the first set of supporting arms 10 is configured to act upon the annular stiffening ring 8 upon application of a force in an inward direction, i.e. towards the axis defined by the draw wire 4. This inward force is provided by means of contact of at least one of the supporting arms making up the first set 10 with a portion of the pipe 100 first connector fitting 102 which defines the opening. In doing so, the sail structure 6, along with the supporting arm sets 10, 12 and annular stiffening ring 8 are moved to a generally elongate configuration which is able to be passed through the opening.

[0091] The collapsed configuration of the sail structure 6 is shown schematically in FIG. 2. In particular, the supporting arms 12 are adapted to be slidably and flexibly connected to the draw wire 4 and the supporting arms 10 are adapted to be flexibly attached to the draw wire 4. Similarly, the annular stiffing ring 8 may be adapted to fold at points where it is connected to the supporting arms 10, 12. This allows the sail structure 6 to be collapsed where necessary, easing the task of inserting/extracting the sail structure from a pipe. In one preferred embodiment, the arms 10, 12 and/or stiffening ring 8 are adapted to provide a biasing force urging the sail structure 6 to the open configuration of FIG. 1.

[0092] Once the sail structure 6, supporting arm sets 10, 12 and stiffening ring 8 are fully passed through the opening in the first connector fitting 102 and are entirely within the interior of the pipe 100, the inward force provided by the contact with the pipe 100/connector fitting 102 is removed and the sail structure 6 returns to an expanded configuration, as shown in FIG. 3B. At this point, the fluid flow within the pipe 100 acts upon the inner face of the sail structure 6 which acts to move the draw wire 4 along the pipe 100 in a direction from the first connector fitting 102 towards the second connector fitting 104. The draw wire 4 is unreeled from wire reel 106 as the wire 4 moves along the pipe 100 as shown.

[0093] At the second connector fitting 104, the illustrated embodiment includes inserting an extraction member 108 through an opening (not shown) within the second connector fitting 104 such that it is entered into the interior of the pipe 100. As mentioned above, the fluid pressure within the pipe 100 and the air pressure within the second connector fitting 104 must be equalised before this takes place.

[0094] The extraction member 108 may comprise a magnetic material and in this way once the magnetic end cap 14 on draw wire 4 has been moved to the region in the pipe 100 proximal to the second connector fitting 104, the extraction member 108, through magnetic engagement with the end cap 14, may be used to withdraw the end of the draw wire 14 from within the pipe 100 through the opening in the second connector fitting 104. The illustrated method additionally comprises monitoring the position of the draw wire 4 within the pipe 100 using micro-sonde 16.

[0095] Subsequent to withdrawing the end draw wire 4 from within the pipe 100, including the sail structure 6, the free end of the draw wire 4 may be attached to a pulling mechanism 114 as shown in FIG. 3C. The pulling mechanism 114 continues the movement of the draw wire along the pipe 100 even after removal of the sail structure 6 from within the pipe 100. At the other end of the draw wire 4 to the free end which is attached to pulling mechanism 114, a first end of an elongate flexible member in the form of a micro-duct 110 is attached thereto as shown in FIG. 3C. The micro-duct 110 is reeled on a pushing mechanism 116, which in conjunction with the pulling mechanism 114 acting on the draw wire 4, acts to move the attached micro-duct 110 along the pipe 100 in a direction from the first connector fitting 102 towards the second connector fitting 104. As with the draw wire 4, the micro-duct 110 is provided with a further micro-sonde 112 which may be used to track the progress of the micro-duct 110 along the pipe as shown in FIG. 3C.

[0096] The first end of the micro-duct 110 is then withdrawn automatically from within the pipe 100 under operation of the push mechanism 116 and pull mechanism 114 without any further input. Once withdrawn at the second connector fitting 104, the first end of the micro-duct 110 may then be connected up with a street cabinet/exchange point or similar for use.

[0097] To complete the process, the method may additionally comprise sealing the openings within the first and second connector fittings 102, 104 around the portion of the micro-duct 110 which is located at these openings. Once the openings have been fully sealed it is no longer necessary to balance the fluid pressure within the pipe 100 with the air pressure within the connector fittings 102, 104 and therefore any external pressure chambers may be removed.

[0098] Subsequent to the process illustrated in these Figures, the method may additionally comprise blowing one or more cables or the like along the installed micro-duct. Such a process may be undertaken using any conventional blowing techniques which are well known in the art.

[0099] FIGS. 3A to 3D illustrate the process in accordance with the invention of laying a single micro-duct 110 along a length of pipe 100. It should however be appreciated that this process is not limited to a single micro-duct, nor is it limited to micro-ducts. In fact, any elongate flexible member may be used in place of the illustrated micro-duct 110.

[0100] FIGS. 4A, 4B, 5 and 6 illustrate the extraction member 108 in further detail. As shown in FIG. 4A, the extraction member 108 comprises a body having a first bore 118 and a second bore 120, the bores extending partly through the body of the extraction member 108. Each of the bores 118, 120 includes an open upper end 122, 124 and a lens 126, 128, the lenses 126, 128 being located at the distal end of the corresponding bore 118, 120 to the open upper end 122, 124. In addition to bores 118, 120, the extraction member includes first and second magnetic surfaces 130, 132, and an annular projection 134 for resting on the surface of a pipe in use to prevent the extraction member 108 from being inserted too far into the pipe.

[0101] The first bore 118 of the extraction member 108 is operable in use to receive a CCTV endoscope mechanism, which is illustrated schematically in FIG. 5. As illustrated, the CCTV endoscope mechanism includes a CCTV endoscope 138, a mounting device 140 and a mirror 142. In use, the mounting device 140 is located within the first bore 118 within the extraction member 108 in close proximity to the lens 126. The endoscope 138 itself is operable to be passed through the bore 118 towards the mounting device 140. The mirror 142 acts to direct light passing through the lens 126 onto the endoscope 138 when the endoscope 138 is positioned in the configuration shown in FIG. 5, i.e. directly above the mirror 142. In use, the endoscope mechanism is used to view along the pipe 100 from outside of the pipe 100.

[0102] The second bore 120 of the extraction member 108 is operable in use to receive an LED illumination mechanism, which is illustrated schematically in FIG. 6. As illustrated, the LED illumination mechanism includes an illumination rod 146 and an LED 148. The rod 146 includes an aperture 150 through which the LED 148 is shone in use. In use, the illumination rod 146 is located within the second bore 120 within the extraction member 108 with the LED 148 being positioned in close proximity to the lens 128. In this way, the LED 148 may be used to illuminate the interior of the pipe 100.

[0103] As stated above, the extraction member 108 also includes first and second magnetic surfaces 130, 132. These surfaces 130, 132 are operable in use to interact and magnetically connect to the magnetic cap 14 on the sail structure 6.

[0104] The configuration of the extraction member 108 as described above allows for the member 108 to be used to view a draw wire as it is moved along a pipe, and subsequently connect with the draw wire to remove the wire from within the pipe as required. This is achieved as the light from the illumination means (LED 148) is directed through the lens 128 down the pipe 100 and the light from within the pipe 100 is directed through the lens 126 and via the mirror 142 onto the endoscope 138. Viewing the draw wire in this manner allows a user to easily direct the extraction member 108 to attach it to the draw wire through the magnetic connection with the sail structure 6 (as described above).

[0105] FIGS. 7A & 7B and show a further embodiment of a system 202 in accordance with the present invention. The system 202 includes a number of identical features to the system 2 illustrated in FIGS. 1 to 6, and therefore like numerals have been used to identify like components. The system 202 additionally comprises a sterilisation chamber 204 for sterilising the draw wire 4 and/or flexible member 110 as it is introduced into the pipe. This is desirable when inserting flexible members into pipes 100 which may usually be used to transport fresh water as without such sterilisation, the fresh water within the pipe 100 may become contaminated. The operational use of the sterilisation chamber 204 will be described in further detail hereinbelow.

[0106] In addition to the sterilisation chamber 204, the system 202 includes a stop tap 208 on the pipe 100 for preventing fluid flow along the pipe if required. The system 202 also differs from system 2 in that the wire reel 106 and push mechanism 116 are replaced by a reel 206a located at one side of the sterilisation chamber 204, and a push mechanism 206b at the other side of the sterilisation chamber 204.

[0107] The sterilisation chamber 204 includes a series of pulley mechanisms 210a, 210b, 210c which guide the draw wire 4 (or subsequently a flexible member 110) through the sterilisation chamber 204. Pulley mechanisms 210a, 210c are located outside of the chamber and act to direct the draw wire 4 into the chamber 204 and out of the chamber 204, respectively. Pulley mechanism 201b is located within the sterilisation chamber 204 and acts to move the draw wire 4 along the chamber 204 in a desired direction. This is shown schematically in FIG. 8.

[0108] In use, the chamber 204 is filled with a fluid 212, usually water, to such a level that the draw wire 4 is completely submerged within the chamber 204. To provide the sterilisation, the fluid 212 is supplied with oxygen enriched with O.sub.3 molecules, commonly termed ozone gas. Ozone gas is a very powerful oxidant with an instant action and so provides sterilisation in a very short time. To provide the ozone gas, the chamber 204 includes a series of ozone bubblers 214a, 214b, 214c, 214d located along a bottom surface of the chamber 204 in close proximity to the draw wire 4 when it is passed therethrough.

[0109] In a further embodiment of the system for sterilisation, such sterilisation may be accomplished by the means of the flow of dry ozone gas over the member to be sterilised, as is shown in FIGS. 8A & 8B. In this embodiment, the sterilisation chamber 224 is adapted to enable the draw wire 4 and/or flexible member 110 to pass through as it is introduced into the pipe 100. The chamber comprises an ozone inlet 215a and an ozone outlet 215b. This enables a flow of ozone gas to be set up in a direction 216 that is the reverse of the direction 217 in which the draw wire 4 or member 110 traverses the chamber 224. The chamber 224 may be provided with lip seals 218 or similar to minimise the egress of ozone gas, ensuring that said gas is exhausted safely via outlet 215b to a remote place.

[0110] The pull mechanism 206b acts, either alone or in combination with the action of the sail surface 6, to pull the draw wire 4 off the wire reel 206a, through the sterilisation chamber 204 and subsequently into the pipe 100.

[0111] FIG. 9 illustrates a further embodiment of a system 302 in accordance with the present invention. As with system 202, system 302 includes many components which are identical to system 2. Therefore like numerals have been used to identify components which are deemed to be equivalent in all systems.

[0112] System 302 differs from the preceding systems in that it also includes a means for the push mechanism 206b or 116 to communicate with the pull mechanism 114 to coordinate the pushing/pulling of the draw wire 4 or flexible member 110 through the pipe 100. In the illustrated embodiment, this communication is done over a wireless connection 308. To enable communication over the wireless connection 308, each of the push/pull mechanisms 114, 116, 206b are suitably connected to a transceiver 310, 312 for transmitting/receiving information over the connection 308. In order to control the information which is transmitted over the connection 308, and also the operation of each push/pull mechanism 114, 116, 206b, the mechanisms are each provided with a control box 304, 306. The control boxes 304, 306 are operable in use to process information received from the other box 306, 304 and adjust the speed at which the corresponding push/pull mechanism 114, 116, 206b is operating accordingly.

[0113] An embodiment of an external pressure chamber 420 is illustrated in further detail in FIGS. 10 to 12. The pressure chamber 420 includes a housing 422 (shown in FIG. 10) and a lid portion 424 (shown in FIG. 12). The housing 422 includes a central cavity 426 having an open upper end 428 and open lower end 430. The chamber housing 422 is configured such that the central cavity has a first section having a first, larger diameter proximal to the open upper end 428 and a second section having a second, smaller diameter proximal to the open lower end 430. The open lower end 430 further comprises an o-ring seal 432 and also a lip seal assembly 434, which is illustrated further in FIG. 11. The purpose of the seals is to provide a fluid-tight barrier to any fluid from within the pipe being expelled out of the pipe, or likewise any fluid within the chamber entering the pipe. As shown in FIG. 11, the lip seal assembly 434 comprises a generally cylindrical configuration and has a bore therethrough which is configured to allow a lower portion 456 of the lid 424 to be introduced therein. The lower surface 440 of the lip seal assembly 434 is tapered in such a way that as the pressure applied to the lip seal assembly 434 increases the sealing force increases as the pressure applied to the lower surface 440 acts to reduce the diameter of the bore.

[0114] The chamber housing 422 also includes a pressurisation port 438 operable in use to allow for the introduction of removal of gas from within the chamber housing 422 in order to equalise the pressure therein, and a pressure meter 436 for monitoring the pressure within the housing 422. The equalisation process may be fully automated.

[0115] The lid portion 424 of the pressure chamber 420 is shown schematically in FIG. 12. The lid portion 424 includes an upper portion 442 which has a slightly larger diameter than the open upper end 428 of the housing 422. In this way, the lid portion 424 may be placed over the open upper end 428 and securely fastened thereto. To ensure no fluid may escape from within the housing 422 through the open upper end 428, the lid portion further includes an o-ring seal 444 provided a fluid-tight seal between the housing 422 and the lid portion 424. The upper portion 442 of the lid 424 also includes an opening 446 therein for connecting a further component of the system 2, 202, 302 thereto. This further component may comprise a push/pull mechanism 114, 116, 206b for example. The opening 446 also includes an o-ring seal for a fluid-tight seal between the lid portion 424 and the further component to prevent any unwanted fluid loss/drop in pressure.

[0116] The lid portion 424 further includes a lower extended portion 450 which has a much smaller diameter to the housing 422. The lower extended portion 450 is configured such that a lower portion 456 of the extended portion 450 is inserted through the bore in the lip seal assembly 434 at the lower end 430 of the housing 422 when the lid portion 424 is securely fastened to the housing 422. The extended portion 450 of the lid portion 424 also includes a bore 452 running therethrough, along with a fluid inlet 454 allowing introduction or removal of fluid from within the bore 452 to control the pressure therein. The bore 452 has a lower open end and an upper end which is located within the upper portion 442, and in particular is located at the opening 446 within the upper portion 442. In this way, a draw wire 4 or other flexible member may be introduced through the opening 446 in the upper end of the lid 424, along the bore 452 and through the lower open end 456 of the bore 452 either directly into the pipe 100 or into a further component of the system 2, 202, 302 such as a first or second connector fitting 102, 104.

[0117] An embodiment of a connector fitting 102 is shown schematically in FIGS. 13A and 13B. The connector fitting 102 includes an open upper end 522 for introduction of a draw wire 4, flexible member 110 or even the lower end 456 of a pressure chamber therein. The connector fitting 102 includes a stepped configuration having a first portion having a first diameter and a second portion having a second, larger diameter. The step 530 in the connector fitting 102 is operable in use to securely fasten the connector fitting either directly onto the pipe, or to another component of the system 2, 202, 302. Furthermore, in the illustrated embodiment, the connector fitting 102 include a spigot recess, allowing for rotational location of the connector fitting into position within the pipe 100.

[0118] In use, the first portion of the connector fitting 102 is located within the pipe 100 and acts to guide the draw wire 4 or flexible member 110 into the interior of the pipe 100. To do so, the illustrated connector fitting further includes a bore 522 having a sloped lower section 526 and a lower opening 532 at the distal end of the bore 522 from the open upper end 522 of the connector fitting 102. The lower opening 532 in the connector fitting 102 allows for the draw wire 4 or flexible member 110 to be passed along the bore 522 and into the pipe 100. The sloped lower section 526 of the bore 522 acts to urge the wire 4 or member 110 to a horizontal position for passing along the pipe 100.

[0119] Whilst the embodiment illustrated in FIGS. 13A and 13B is described as being a first connector fitting 102, it is equally suited to being a second connector fitting 104 at the second point on the pipe 100.

[0120] The above embodiment is described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims.