TECHNICAL FIELD The present invention relates to pipelines and in particular but not exclusively apparatus for use in the maintenance or installation of pipelines.

BACKGROUND Maintenance, upgrading and replacement of ageing utilities pipeline infrastructures are major issues facing utilities companies such as water and gas utilities companies. Pipeline networks typically include main supply pipelines (also referred to as the 'mains' supply) and consumer service connection pipelines. The consumer service connection pipelines are connected to the main supply pipelines, typically by means of a T-connection, to deliver a supply of fluid such as water or gas to a consumer's premises from the main supply pipeline.

Utilities supply pipelines are typically located underground, presenting substantial access issues when maintenance, upgrading or replacement is required.

Ageing pipelines are vulnerable to failure and leakage of fluid from pipelines is a known hazard particularly in the case of gas leakage.

One solution to reducing the cost of replacement of pipelines is to install replacement pipeline within pre-existing pipeline, including the main pipeline and consumer service connection pipeline, leaving the pre-existing main pipeline and pre-existing consumer service connection pipeline in place. The replacement main pipeline has an external diameter that is smaller than the internal diameter of the pre-existing main pipeline, allowing it to fit within the pre-existing main pipeline infrastructure. Similarly, the replacement consumer service connection pipeline has a diameter that is smaller than the pre-existing consumer service connection pipeline. The replacement main pipeline may be referred to as a 'main pipeline liner' or 'mains liner' because it effectively lines the pre-existing main pipeline. Similarly the replacement consumer service connection pipeline may be referred to as a 'service connection liner' since it effectively lines the pre-existing consumer service connection pipeline. The consumer service connection pipeline may be of the Serviflex (RTM) type, being a twin wall corrugated flexible polyethylene liner pipe supplied by Radius Systems Ltd, South Normanton, Alfreton, Derbyshire, UK.

In known methods of replacement pipeline installation, the replacement pipeline is installed within the pre-existing pipeline by pulling the replacement pipeline through the pre-existing pipeline. Connection of the replacement consumer service connection pipeline to the replacement main pipeline is made by excavating ground above the location at which the pre-existing service connection pipeline connects to the pre-existing main pipeline. Installer personnel may then remove a portion of the pre-existing main pipeline and pre-existing service connection pipeline in order to expose the replacement pipelines that have been installed therein. A T-connector is then installed on the replacement main pipeline and the replacement service connection pipeline coupled to the replacement main pipeline via the T- connector. The T-connector is typically attached to the main pipeline by forming an electrofusion bond between the T-connector and the main pipeline in a known manner.

It is an aim of the present invention to address disadvantages associated with the prior art.

SUMMARY OF THE INVENTION Embodiments of the invention may be understood with reference to the appended claims.

Aspects of the present invention provide an apparatus, a robot, a system and a method.

In one aspect of the invention for which protection is sought there is provided apparatus for providing a fluid connection to a pipeline, the apparatus comprising:

propulsion means for propelling the apparatus along the pipeline within the pipeline; means for forming an aperture in a wall of the pipeline from within the pipeline; and means for coupling to the pipeline from within the pipeline a fitting comprising at least a portion of a connector for making a service connection to the pipeline via the aperture.

Embodiments of the present invention have the advantage that the making of a fluid-tight connection to a pipeline may be made in a convenient manner without a requirement for external access to a pipeline at the point the connection is required to be made. Rather, access to the pipeline may be made at any convenient location and the apparatus delivered to the required location within the pipeline. Some embodiments of the invention may be configured for operation in pipelines having a diameter of 1 m or less, optionally in the range from 10mm to 1 m. Some embodiments may be configured for operation in pipelines having a diameter in the range from 50mm to 200mm, optionally from 50mm to 100mm, optionally in the range from 75mm to 90 mm.

Optionally, the means for coupling the fitting comprises means for installing a fitting for making a substantially fluid-tight connection to the pipeline via the aperture. Optionally, the fitting is configured to permit a service connection to be made to a service connection pipeline via the aperture.

Optionally, the apparatus comprises at least one robot, the at least one robot comprising the propulsion means, at least one said at least one robot comprising the means for forming an aperture, at least one said at least one robot comprising the means for installing the fitting.

Optionally the apparatus comprises a single robot comprising the propulsion means, the means for forming an aperture and the means for installing the fitting. Thus the robot may be configured to move along the pipeline, form an aperture and install the fitting in the pipeline.

Optionally, the means for forming an aperture comprises an aperture-forming module configured to form the aperture in the sidewall of the pipeline.

Optionally, the aperture-forming module comprises a drill portion configured to drill an aperture in the sidewall of the pipeline.

Optionally, the means for installing the fitting comprises means for positioning the fitting for attachment to the pipeline.

Optionally, the means for installing the fitting comprises means for storing at least one fitting and means for positioning the at least one fitting for attachment to the pipeline. Optionally, the means for installing the fitting comprises means for heating the fitting. Optionally, the means for heating the fitting comprises at least one selected from amongst means for irradiating the fitting with radiation, means for irradiating the fitting with infra-red radiation, means for blowing heated air over the fitting, means for passing an electrical current through an electrofusion coil of a fitting and means for causing the fitting to contact an edge of the pipeline defining the aperture and to rotate about an axis thereby to cause formation of a friction weld between the fitting and pipeline.

Optionally, the apparatus further comprises a leak-test portion for leak-testing a joint between the fitting and pipeline, the leak-test portion comprising sealing means, the leak- test portion being arranged to form a seal between the leak test portion and an inner wall of the pipeline by means of the sealing means to define a test volume within the pipeline that is sealed in a fluid-tight manner from a remainder of the pipeline.

The apparatus may be configured to inject pressurised fluid into the test volume to test an integrity of a joint between the fitting and pipeline.

The apparatus may be configured to inject pressurised gas into the test volume.

Optionally, the leak-test portion is configured to inject the pressurised fluid into the test volume.

The apparatus may comprise a pressurised fluid storage tank, optionally a pressurised gas storage tank. The tank may be referred to as a ballast tank. The tank may be configured to be provided with compressed gas via a pneumatic fluid supply line that runs from the robot to a remote location, optionally to an environment external to the pipeline. The tank may be configured to supply pressurised gas to any portion of the robot requiring such gas via one or more separate pneumatic supply lines, one or more of which may be of larger diameter than the pneumatic fluid supply line providing fluid from the external environment to fill the ballast tank. For example gas required to actuate one or more actuators, or for leak testing of a portion of the pipeline, may be supplied from the ballast tank. The presence of the ballast tank has the advantage that relatively high flow rates of gas may be provided compared with the rates obtainable via a relatively small diameter fluid supply pipeline that runs from the external environment. It is to be understood that in some embodiments it is important to maintain the weight of any cabling running from the robot to the external environment as low as possible, particularly where the robot is required to propel itself along the pipeline dragging the cabling behind it. Accordingly, provision of a separate onboard ballast tank may enable operation of the robot relatively long distances along the pipeline in circumstances where operation would otherwise not be possible, or would be required to proceed at a slower rate due to the time taken to pump pneumatic fluid to the robot from the external environment.

In one aspect of the invention for which protection is sought there is provided a robot module comprising a pressurised fluid storage tank. The pressurised fluid storage tank may be configured to be supplied with pressurised fluid from an environment external to the module, optionally from an environment external to a pipeline, via a conduit such as a pneumatic line.

In a further aspect of the invention for which protection is sought there is provided a robot comprising a module comprising a pressurised fluid storage tank, the pressurised fluid storage tank being configured to be supplied with pressurised fluid from an environment external to the robot via a conduit such as a pneumatic line. The robot may comprise one or more pneumatically driven actuators, the actuators being configured to be driven by pneumatic fluid supplied from the pressurised fluid storage tank.

In a further aspect of the invention for which protection is sought there is provided a method for providing a fluid connection to a pipeline, comprising:

propelling an apparatus along the pipeline within the pipeline;

forming by means of the apparatus an aperture in a wall of the pipeline from within the pipeline; and

coupling a fitting to the pipeline from within the pipeline by means of the apparatus, the fitting comprising at least a portion of a connector for making a service connection to the pipeline via the aperture.

The method may comprise coupling a second pipeline to the first pipeline by means of the fitting.

The method may compriseleak-testing a joint between the fitting and pipeline by means of a leak-test portion of the apparatus, the method comprising forming a fluid-tight seal between the leak test portion and an inner wall of the pipeline around substantially the whole of the fitting by means of sealing means whereby the fitting is isolated by means of the sealing means from a remainder of an internal volume of the pipeline beyond the sealing means. The method may comprise injecting pressurised fluid into a volume at least partially enclosed by the sealing means in order to leak-test a joint between the fitting and pipeline.

Within the scope of this application it is envisaged that the various aspects, embodiments, examples and alternatives, and in particular the individual features thereof, set out in the preceding paragraphs, in the claims and/or in the following description and drawings, may be taken independently or in any combination. For example features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.

For the avoidance of doubt, it is to be understood that features described with respect to one aspect of the invention may be included within any other aspect of the invention, alone or in appropriate combination with one or more other features. BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying figures in which:

FIGURE 1 is a plan view schematic illustration of a pipeline robot according to an embodiment of the present invention;

FIGURE 2 is a cross-sectional view of a typical operating environment of a pipeline robot according to an embodiment of the present invention; FIGURE 3 is a 3D view of a primary interface module according to an embodiment of the present invention;

FIGURE 4 is a cross-sectional schematic view of a portion of a drill module normal to a longitudinal axis of the drill module showing the drill module in the process of cutting an aperture in a sidewall of a pipeline;

FIGURE 5 shows (a) a 3D schematic view of a pipe fitting according to an embodiment of the present invention being raised towards an aperture that has been cut by the drill module in the sidewall of a pipeline without showing the robot that lifts the fitting, and (b) a cross- sectional schematic view of a pipe fitting for use in embodiments of the invention; FIGURE 6 is a plan view of a storage portion of a fitting insertion module for use in embodiments of the invention showing the fitting at (a) a first position and (b) a second position different from the first after being conveyed by the storage portion; FIGURE 7 is a plan view schematic illustration showing (a) a fitting before passing from the storage portion through a latch or gate mechanism to a heater portion; (b) a fitting during passage through the latch mechanism; (c) the fitting situated in a heater portion after passing through the latch mechanism; and (d) the fitting after being transferred from the heater portion to a lift portion for lifting the fitting to install the fitting in the sidewall of the pipeline;

FIGURE 8 is a side view schematic illustration showing a fitting (a) before being lifted by the lift portion and (b) after being lifted by the lift portion to install the fitting in the sidewall of the pipeline;

FIGURE 9 is a 3D view of a portion of a leak test module for performing leak testing of a fitting;

FIGURE 10 is a side view of a portion of a leak test module (a) before and (b) after raising a seal element thereof form a fluid-tight seal to a sidewall of the pipeline;

FIGURE 1 1 shows (a) a plan view and (b) a front view of a portion of a leak test module according to an embodiment of the present invention; FIGURE 12 is a 3D view of a leak test module according to a further embodiment of the invention;

FIGURE 13 is a side view of the leak test module of FIG. 13 with inflatable bags in (a) a deflated condition and (b) an inflated condition; and

FIGURE 14 is a side view of the leak test module of FIG. 13 showing internal detail with one inflatable bag inflated.

DETAILED DESCRIPTION FIG. 1 is a plan view schematic illustration of a pipeline robot 100 located within a newly installed utilities main pipeline 101. A reduced scale view of a typical operational environment of the robot 100 is shown in FIG. 2. It can be seen from FIG. 2 that, in the scenario illustrated, the robot 100 has been introduced into a newly installed main pipeline 101 via an underground inspection well 101 A. It is to be understood that the free end 10 F of the main pipeline 101 that is exposed to the well 101 A may be coupled to the free end 101 F2 of a second length of newly installed main pipeline 101 that also terminates in the well 101 A once service connection pipelines have been connected to the main pipeline 101 . The newly installed utilities main pipeline 101 is itself located within a pre-existing main pipeline 101 E of larger diameter.

The robot 100 is configured to install a pipeline fitting in a newly installed main pipeline in order to allow a service connection pipeline to be connected to the main pipeline. The module achieves this by drilling an aperture in a sidewall of the pipeline and coupling the pipeline fitting to the pipeline in order to allow a fluid-tight connection to be made between the service connection pipeline and main pipeline. The robot 100 is also able to test the integrity of a joint between a service connection pipeline and the main pipeline. This allows an operator to determine whether or not a successful connection of the service connection pipeline to the main pipeline has been made.

The robot 100 has six modules coupled to one another in series. In the embodiment shown in FIG. 1 the modules are a tractor module 1 10, a compressed air ballast module 120, a drill module 130, an insertion module 140, a leak test module 150 and a trailer module 160. In some embodiments a second tractor module 1 10 may be coupled to the leak test module 150 instead of the trailer module 160. One or more additional modules may be included in some embodiments. In some embodiments the trailer module 160 may be eliminated. It is to be further understood that the modules may be coupled to one another in a different order in some embodiments. For example, in some embodiments the ballast module 120 may be provided adjacent the leak test module 150. In addition or instead the ballast module 120 may be provided adjacent the insertion module 140, for example if the insertion module 140 is powered by pneumatic means such as a pneumatic piston or pneumatic motor.

Each module has at least three support arms 11 OR, 120R, 130R, 140R, 150R, 160R that are configured to project outwardly therefrom at an acute angle with respect to a longitudinal axis of each module. The support arms pivot about an axis at a proximal end within a body portion 1 10B-160B of each module 110-160. Each arm is spring-loaded and carries a roller in the form of a wheel at its free end. The arms are configured to urge the respective rollers away from the body portion 1 10B-160B and against an inner wall of the pipeline 01 in order to support the modules 1 10-160 substantially coaxial of the pipeline 101 . The spring loading of the arms 1 10R-160R assists the robot 100 to maintain a coaxial location whilst accommodating variations in diameter or cross-sectional shape of the pipeline 101 , for example regions that are not circular such as oval or other non-circular regions, and to negotiate bends in the pipeline 101. It is to be understood that maintain a coaxial location is not necessarily critical in all applications.

The tractor, ballast and trailer modules 110, 120, 160 each have four support arms 11 OR, 120R, 160R, respectively arranged in quadrature about the longitudinal axis of the modules. In the orientation shown in FIG. 1 one arm projects substantially vertically upwardly, one arm projects substantially vertically downwardly and two arms project substantially laterally in opposite directions.

The drill, insertion and leak test modules 130, 140, 150 each have three support arms 130R, 140R, 150R, one arm projecting substantially vertically downwardly and two arms projecting substantially laterally in opposite directions in the orientation depicted in FIG. 1.

In some alternative embodiments, one or more of the modules may have rollers that are attached to a body of the module rather than to spring-loaded arms. The rollers may be non spring-loaded in some embodiments, being configured to rotate about an axis at a substantially fixed distance from a longitudinal axis of the respective module of which they form part. For example, one or more rollers may be provided such as wheels, caterpillar tracks or other suitable roller arrangements. The rollers may be arranged such that the robot 100 may crawl along the pipeline 101 with the rollers contacting only a lower internal surface area of the pipeline 101. In the embodiment of FIG. 1 the rollers of the tractor module 1 10 are configured to be driven by electric motors that are powered by means of an electrical powerline carried by an umbilical cable 100C. The umbilical cable 100C runs along a length of the robot 100 along a conduit provided through each module. The tractor module 110 also carries an onboard robot control portion 1 15. The onboard control portion 1 15 includes a computing device that is in data communication via a data line carried by the umbilical cable 11 OC with a main or primary interface module 1 10PM external to the pipeline 101 as shown schematically in FIG. 2. The primary interface module 110PM is connected to a secondary interface module 110SM which in the present embodiment is provided by a portable computing device having a keyboard and display screen. The secondary interface module 1 0S allows a user to control the primary interface module 10PM to send electrical control and power signals, and supply compressed air at a required pressure, to the robot control portion 1 15. By means of the secondary interface module 110SM an operator may control the tractor module 1 10 to cause the robot 100 to move in a forward and reverse direction within the pipeline 101 and to operate each of the drill module 130, insertion module 140 and leak test module 150 to install a pipe fitting allowing connection of a consumer service pipeline to a main pipeline. The robot 100 may also be controlled to leak-test the newly connected consumer service pipeline. It is to be understood that, in the event the robot becomes immobilised for any reason within the pipeline 101 , the robot may typically be retrieved by pulling on the umbilical cable 1 10C.

The primary interface module 1 10PM is shown in more detail in FIG. 3. The module 110PM has a pressure gauge 0PMA allowing an operator to monitor the pressure of a compressed air line carried by the umbilical cable 100C, the compressed air line being fed by a compressor (not shown) externa! to the module 1 10PM. The module has a power supply unit (PSU) 1 10PMC that supplies electrical power to a video processing portion having frame grabber boards 110PMB, a transceiver 1 10PMD for coordinating transmission of data and control signals between the primary interface module 1 10PM, secondary interface module 110SM and robot 100, data from the robot 100 being received by the module 110PM via a data acquisition (DAQ) module 110PME. A pneumatic control valve 110PMF connects the compressor to a compressed air storage tank (ballast tank) of the compressed air ballast module 120 when the pressure therein falls below a predetermined value. An input/output panel 110PMG permits connection of the secondary interface module 110SM and other devices to the primary interface module 110PM as required. The umbilical cable connects to the primary interface module 1 10PM via a cable connector 110PMI.

The drill, insertion and leak test modules 130, 140, 150 each carry a respective tool for performing an operation associated with the module. In addition the modules each carry a respective video camera unit 130C, 140C, 150C. The video camera units are configured to supply a video signal to the primary interface module 110PM allowing an operator to view the immediate operating environment of the respective module and an operational state of the too! carried by each module. Drill Module

The drill module 130 carries a drill tool 131 for forming an aperture in a wall of the pipeline 101. An enlarged view of a portion of the drill module 130 showing the drill tool 131 is presented in FIG. 4. Also shown in FIG. 4 is the replacement main pipeline 101 , pre-existing main pipeline 101 E, replacement consumer service connection pipeline 102 and pre-existing consumer service connection pipeline 102E. The drill tool 131 has a drill bit 131 B that may be caused to rotate by an electric motor. In some alternative embodiments the drill bit 131 B may be caused to rotate by means of a pneumatically driven motor. The drill bit 13 B is mounted on a support portion 133 that may be raised and lowered with respect to the orientation of the robot 100 shown in FIG. 4, allowing the drill bit 131 B to be urged against an upper portion of the wall of the pipeline 100 in order to drill an aperture therethrough.

The video camera unit 120C permits an operator to view the drill bit 121 B and the portion of the wall of the pipeline 101 in which the drill bit 12 B will form an aperture. This is so as to ensure that the aperture is cut at a required location. The video camera unit 120C permits an operator to monitor the drilling of the aperture to ensure correct operation of the module 120. FIG. 4 shows the drill too! 121 of the drill module 120 during a process of forming an aperture in a wall of the pipeline 101 .

It is to be understood that, if the main pipeline 101 is formed from an optically translucent material, an operator may determine the location at which an aperture is to be formed in the pipeline 101 by illuminating an external surface of the main pipeline 101 at the location at which the aperture is to be formed. It is to be understood that the external surface of the pipeline 101 may be illuminated at the desired location of the aperture by passing a source of illumination such as a lamp down a newly installed service connection pipeline 102 or a pre-existing service connection pipeline 102E and illuminating the pipeline 100. A beam of light that is being emitted by a lamp within the replacement consumer service connection pipeline 102 is shown at 102L in FIG. 3. An operator of the robot 100 may employ the camera 130C to identify the area of the main pipeline 101 illuminated by the light from the light source by searching for an area of the wall of the main pipeline 101 that is being illuminated. Insertion Module

The insertion module 130 carries a set of pipe fittings, also referred to as remote fittings, that are attached by the insertion module 130 to the main pipeline 101 in order to enable the main pipeline 101 to be connected to the newly installed service connection pipeline 102. FIG. 5(a) shows a fitting 140F being presented to an aperture 101 AP formed in the main pipeline 101 by the drilling tool 131 of the drill module 130 whilst FIG. 5(b) is a cross- sectional illustration of a fitting normal to a cone axis A of the fitting 140F. The fitting 140F is substantially frustoconical in shape having a radially outer frustoconical surface 140FS that is sized to abut an edge of the pipeline 101 defining the aperture 101 AP. The surface 140FS has grooves 140FSG to promote coupling of the fitting to a pipeline 101. It is to be understood that the fitting 140F may partially deform in sliding contact with the aperture 140AP when urged upwardly into the aperture 101 AP, the fitting 140F forming a snap-fit to the pipeline 101 with an edge of the pipeline 101 defining the aperture 101AP trapped within one of the grooves 140FSG.

In some embodiments the frustoconical outer surface 140FS of the fitting 140F may be substantially smooth or of any other desired surface texture or form. With respect to the orientation in which the fitting 140F is depicted in FIG. 5, a lower circumferential edge 140FE of the fitting 140F is shaped to conform to that of an outer surface of a cylinder of similar diameter to that of the pipeline 101 in the orientation shown. This is so as to reduce the amount by which the fitting 1 0F protrudes diametrically into the pipeline 101 , thereby reducing disturbance of the flow of fluid such as gas along the pipeline 101 in which the fitting 140F is installed.

FIG. 6 is a plan view of a fitting storage portion 142 of the insertion module 140 in which the module 140 is arranged to store fittings 140F, and from which fittings are dispensed. The fitting storage portion 142 has a pair of worm screws 142H each having a helical thread provided therealong. The worm screws 142H are disposed parallel to a longitudinal axis of the insertion module 140 and support fittings 140F along the length of the worm screws 142H. It is to be understood that coordinated rotation of the worm screws 142H causes fittings 140F to be translated in a longitudinal direction along the worm screws to a first end 142H1 at which a jaw portion 142J is provided. The jaw portion 142J has a one-way latch or gate mechanism 142L. A fitting 140F may be conveyed by the worm screws 142H past the latch mechanism 142L to a heating portion of the module 140. FIG. 7(a) to (c) shows a sequence of images of a fitting 140F being loaded into a heating portion of the module 140. It can be seen that the latch mechanism opens as the fitting 140F is conveyed through the mechanism 142L, the mechanism latching closed behind the fitting 140F as shown in FIG. 7(c). In the illustrated embodiment the fitting 140F is heated by means of an infra-red illumination source 143 arranged so that it is positioned below the fitting 140F when the fitting 140F is in the heating portion. In some embodiments one or more sources of infra-red radiation may in addition or instead be positioned so as to irradiate a radially outer surface 140FS of the fitting 140F. Once the fitting 140D has been heated to a required temperature, the fitting 140F is translated to a lift portion 144 of the module 140 that is configured to lift the fitting 140F into abutment with the portion of the pipeline 101 defining the aperture 101 AP. It is to be understood that the module 140 is configured such that the fitting may be conveyed to the lift portion 144 and the lift portion 144 lift the fitting 140F sufficiently quickly to enable the fitting 140F to be installed in the aperture 101 AP before the fitting 140F cools to too low a temperature to form a fluid-tight sea! to the pipeline 101 around the aperture 101AP.

The lift portion 144 is shown in side view in FIG. 8. A saddle member 144S in the form of a curved hoop or curved U-shape member is supported by a worm screw member 144SH having a helical thread. The worm screw member 144SH is disposed parallel to a longitudinal axis of the lift module 140 and is configured to cause the saddle member 144S to move to and fro along a portion of a length of the worm screw member 144SH. Free ends of the saddle member 144SH are coupled to one of two arms of a scissor lift mechanism that allows a fitting support portion 144FS to move in an upward direction with respect to the orientation of the module 140 depicted in FIG. 8. This is a direction normal to a longitudinal axis A of the module 140 shown in FIG. 8(a).

It is to be understood that any suitable mechanism may be employed for translating the fitting support portion 144FS, and thereby a fitting 140F, to its intended location in the sidewall of the pipeline 101.

As noted above, in some alternative embodiments the insertion module 140 may comprise a spinner portion, which may be similar to the drill tool 131 of the drill module 130 described above but configured to support a fitting 140F instead of a drill bit 131 B. The spinner portion may be configured to spin the fitting 140F whilst pressing or urging the fitting 140F into the aperture 101AP formed in the sidewall of the pipeline 101 to connect the fitting 140F to the pipeline 101 by friction welding. In some sti!l further embodiments the insertion module 140 may be provided with electrical contacts for forming an electrical connection to an electrofusion coil embedded within or otherwise forming part of the fitting 140F. The insertion module may be configured to cause an electrical current to flow through the fitting 140F before and/or during urging of the fitting 140F into the aperture 101 AP by the lift portion 144.

Once a fitting 140F has been coupled to the sidewall of the pipeline 101 by raising of the lift portion 144, the robot 100 may be configured to retract the fitting support portion 144FS once the fitting 140F has been attached to the pipeline 101 .

Leak-test Module

The leak-test module 150 permits testing of the integrity of the connection of the fitting 140F to the pipeline 101. A leak-test portion 151 of the leak-test module 150 is shown in FIG. 9 and FIG. 10. In the present embodiment the leak-test portion 151 is configured to form a seal by means of a seal element 5 S carried on a seal element support carriage 151 SC. The support carriage 151 SC may be raised and lowered along an axis B normal to a longitudinal axis A of the module 150; the carriage 151 SC is shown in a lowered or retracted position in FIG. 10(a) and a raised, lifted or deployed position in FIG. 10(b). The support carriage 151 SC has a pair of roller bearings 151 RB mounted on opposite lateral sides at one end thereof. The roller bearings 151 RB are arranged to be constrained to move up and down within a slot 151 RBS having a width slightly wider than a diameter of the roller bearings 151 RB so that movement of the carriage in a direction parallel to the longitudinal axis A is constrained to a relatively small amount whilst still allowing free rotation of the roller bearings 151 RB as the carriage 151 SC moves up and down between the lowered and raised positions. The support carriage 151 SC is raised and lowered by a pair of lift bars provided on each side of the carriage 151 SC. On each side, a first end of first and second lift bars is coupled to the carriage at longitudinally spaced locations, opposite ends being coupled to a tie bar 151TB that runs in a substantially horizontal direction parallel to the longitudinal axis A. The lift bars 151 LB are coupled to the tie bar 151 TB by means of respective hinge joints 151TBJ. The hinge joints 151 TBJ carry roller bearings that are slidable in substantially horizontally disposed, elongate tie bar slots 151 TBS formed in a frame member 150F of the module 150 that is provided on each side of the module 150. The tie bar 151 TB is arranged to be moved in a horizontal direction by means of a pneumatically driven piston 151 P. The piston 151 P is supplied with compressed air at a pressure of 7Bar from the ballast tank 125 of the ballast module 120. FIG. 11 (a) is a plan view of a portion of the leak-test portion 151 showing an enlarged view of the seal element 151 S and the support carriage 151 SC. FIG. 11 (b) is a front view of a portion of the leak-test portion 151 showing an enlarged view of the seal element 151 S and the support carriage 151 SC. The seal element 151 S is substantially circular in plan view but an upper edge 151 SE thereof is shaped to conform to an internal cylindrical surface of the pipeline 101. A camera 155 is located substantially concentric of the seal element 151S as viewed in plan view and is oriented to allow a user to view a location of the pipeline 101 at which the seal element 151 S will form a seal when the seal element 151 S is urged against the pipeline 101 . A pressure sensor 156 is located adjacent the camera 155 on one side thereof whilst a pressurised air outlet valve 156V is located adjacent the camera 155 on the opposite side thereof. The outlet valve 156V is arranged to supply air from the ballast tank 125 of the ballast module 120 at a pressure of 350mbar through an air outlet aperture 1560UT into the volume sealed by the seal elements 151 S when required.

It is to be understood that, in the present embodiment, the fitting 140F is open at both ends, to allow gas to flow from the main pipeline 101 to a service connection pipeline 102 once connected to the fitting 140F. It is to be understood that, in the present embodiment, a replacement service connection pipeline 102 is connected to the fitting 140F prior to leak testing the fitting 140F. It is to be understood therefore that leak testing of the fitting 1 0F has the dual effect of testing the integrity of both the fitting 140F and the connection made by the replacement service connection pipeline 102 to the fitting 140F. In the present embodiment the service connection pipeline 102 is connected to the fitting 140F by means of a mechanical engagement mechanism that is actuated to make a fluid-tight connection to when the service connection pipeline 102 is urged towards the fitting 140F. In use, once a service connection pipeline 102 has been connected to the fitting 140F, a free end of the service connection pipeline 102 is sealed. With the support carriage 151 SC in the lowered position the camera 155 is employed to position the seal element 151 S directly beneath the fitting 140F such that a fluid-tight seal may be formed to the pipeline 101 around the seal element fitting 140F. The pneumatically driven piston 151 P is then actuated to drive the support carriage 151 SC to the raised position and cause the seal element 15 S to be urged against the inner surface of the pipeline 101. A predetermined pressure is then established in the pneumatic piston 151 P to urge the seal element 151S against the pipeline wall. In the present embodiment this pressure is around 5bar although in some alternative embodiments the pressure may be any suitable pressure such as a pressure in the range from 1 to 7 bar.

Once the seal element 151 S is in sealing engagement with the sidewall of the pipeline 101 the robot 100 is configured to bleed compressed air into the volume enclosed by the seal element 15 S via pneumatic valve 156V. Air is bled in to a pressure of 350mbar in the present embodiment although other pressure values may be useful in some embodiments.

The pressure sensor 156M is configured to monitor the pressure and, once the pressure has reached around 350mbar the valve 156V is closed. The pressure sensor transmits a signal indicative of measured pressure to the onboard robot control portion 115 which in turn transmits a pressure value to the primary interface module 110PM. The secondary interface module 110SM reads the pressure value received by the primary interface module 110PM and displays the value on the display screen thereof. In some embodiments the secondary interface module 1 10S monitors the pressure value for a predetermined time period and determines whether an acceptably fluid tight connection between the replacement main pipeline 101 and replacement service connection pipeline 102 in dependence on the amount of any drop in pressure measured by the pressure sensor 156M and detected by the secondary interface module 110SM. If any measured drop is less than a predetermined amount, for example an amount consistent with leakage past the seal formed between the seal element 151 S and pipeline 101 rather than due to the connection between the replacement main pipeline 101 and replacement service connection pipeline 102, the secondary interface module 110SM determines that the connection is acceptable and provides a corresponding indication to an operator of via the display screen.

It is to be understood that other arrangements may be useful in some embodiments. As noted above, in the present embodiment the drill, insertion and leak-test modules are coupled to one another to form a single robot apparatus, in some alternative embodiments one or more of the modules may be provided by two or more separate robots that are not mechanically connected to one another. The two or more robots may be configured to move independently of one another in some embodiments. In some embodiments the two or more robots may be in communication with one another, optionally via a cable and/or via wireless communications means. FIG. 12 illustrates a leak test (or 'pressure test') module 250 according to a further alternative embodiment of the invention. Like features of the module 250 of FIG. 12 to those of the module 150 of FIG. 9 to 11 are shown with like reference signs incremented by 100.

The module 250 illustrated in FIG. 12 employs a pair of axially spaced annular inflatable bags 251 S to seal against an inner surface of the pipeline 101 either side of a newly installed fitting 140F. The bags 251 S are located about a longitudinal axis L of the module 250 and are inflated by means of a pneumatic supply line that supplies compressed air to the bags 251 S via a respective control valve.

FIG. 12 shows the leak-test module 250 with one bag 251 S deflated and one bag 251 S inflated. FIG. 13(a) is a side view of the module 250 with both bags 251 S deflated whilst FIG. 13(a) is a side view of the module 250 with both bags 251 S inflated. It is to be understood that the module is shown in each of FIG.'s 12 and 13 outside of a pipeline 101 , such that expansion of the inflated bags 251 S is not constrained by a wall of the pipeline 101. It is to be understood that a maximum diameter of the bags 251 S when inflated within a pipeline 101 will correspond to the inner diameter of the pipeline 101 and will typically be less than the corresponding diameter of the bags 251 S in their unconstrained condition, inflated to the same pressure, as shown in FIG. 13 (b).

The leak test module 250 has a camera 255 provided therein and directed radially outwardly towards an inner diameter of a pipeline 101 in which the module 250 is located, to enable an observer to locate the fitting 140F to be tested. Once the fitting 140F has been located the module 250 may be held in a substantially fixed location with the pipeline 101 and the inflatable bags 251 S inflated to form an air tight sea! against the pipeline 1 10 either side of the location of the fitting 140F.

It is to be understood that, with the bags 251 S in the inflated condition, air bled into the volume of the pipeline 101 between the bags 251 S is unable to escape from the volume between the bags 251 S by moving beyond the bags 251 S. The module 250 permits air to be introduced into this volume via an air outlet valve 256V through an air outlet aperture 2560UT as shown in the schematic sectional illustration of FIG. 14. In use, the bags 251 S are inflated to a predetermined pressure which may be measured by respective pressure sensors, and subsequently air bled into the volume external to the module 150 between the bags 251 S. A pressure sensor within the module 250 enables measurement of the pressure at the air outlet 2560UT and therefore the pressure external to the module 250 between the bags 251 S. In the present embodiment, the onboard robot control portion 115 of the robot 100 stores pressure reading data generated by one or more of the pressure sensors.

It is to be understood that in some embodiments the leak test module 250 may be capable of performing leak-testing in pipelines of different respective inner diameters by inflating the bags 251 S by different amounts depending on the inner diameter of the pipeline 101 . Thus it is to be understood that the bags 251 S may be inflated to a greater predetermined pressure in the case of leak-testing of pipelines of greater internal diameter than in the case of leak- testing of pipelines of lower internal diameter, where a lower predetermined pressure of air (or other gas) in the bags 252S may be employed, in the present embodiment the leak-test module 250 is configured to be suitable for operations in pipelines 101 having an internal diameter in the range from 75mm to 90 mm at least.

In the present embodiment, the module 250 is configured such that it is capable of sealing a volume within a pipeline such that a pressure of 350mBar may be maintained in a volume under leak test for a period of at least 5 minutes, assuming that no leakage occurs via a leak source other than between the bags 251 S and pipeline wall.

In the present embodiment the bags 251 S are in the form of annular tubes. In flattened (deflated) form, axially distant circumferential edges of the tubes are clamped between respective axially adjacent components 250C1 , 250C2 and 250C2, 250C3 of the module 250 in order to constrain movement of the bags 251 S.

In the present embodiment, the axial distance L1 between the two bags 251 S of the module is around 88mm. The bags in their uninfiated condition as shown in FIG. 13(a) have a diameter of around 55mm whilst in the inflated condition of FIG. 13(b) the bags 251 S have a diameter of around 64mm. Other sizes may be useful in some embodiments, depending on the inner diameter of the pipeline 101 under test. Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of the words, for example "comprising" and "comprises", means "including but not limited to", and is not intended to (and does not) exclude other moieties, additives, components, integers or steps.

Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires, in particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.