Apparatus and method

Abstract

An apparatus 101 for providing access to an interior of an object such as a pressurised pipe (P), the apparatus comprising: a body member 110 having an internal barrel; a base 110B, the base 110B being arranged to be coupled to the object such that the internal barrel of the body member 110 may be provided in fluid communication with an interior of the object; and a piston 120, the piston 120 being slidable within the barrel of the body member 110 along a longitudinal axis 120A of the piston 120 towards the object by axial translation of the piston 120, wherein the body member 110 is rotatably coupled to the base 110B such that the body member 110 may be rotated with respect to the base 110B about a first body member rotation axis 110R1 that is non-parallel to the longitudinal axis 120A of the piston 120, the first body member rotation axis 110R1 having non-zero directional components both parallel to and orthogonal to the longitudinal axis 120A of the piston 120.

Description

TECHNICAL FIELD The present invention relates to equipment for gaining and providing access to pipes, conduits, containers, and other such vessels that may be used to hold fluids. In particular but not exclusively the invention relates to equipment for allowing access to the inside of such vessels whilst such vessels are under pressure, without requiring the vessel to be drained or isolated. BACKGROUND In the oil and gas industry it is frequently required to gain access to pipework to carry out inspection or repair work. This often involves a requirement to gain access inside the pipework. In this, and in other industries, it can be inconvenient and expensive to empty, or otherwise decommission the pipe to carry out such work, and so there is a requirement to be able to access the inside of such pipes while they are in use. The fluids being transported or stored in the pipes are generally under pressure. Tools exist for allowing access to vessels under pressure, these generally being known in the industry as retrievers. Retrievers comprise a mechanism that is attachable, or in some cases permanently attached, to a vessel, generally via a valve, that essentially comprise a fixed shaft along with a moveable portion, e.g. a rod, with appropriate seals being located therebetween, wherein the moveable portion is able to be fed into a hole in the vessel (via the valve if fitted). Known retrievers have the disadvantage that the insertion mechanism makes it difficult to insert items such as cameras having long leads attached thereto. 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 and a method. In one aspect of the invention for which protection is sought there is provided an apparatus for providing access to an interior of an object such as a pressurised pipe or the like, the apparatus comprising: a body member having an internal barrel; a base, the base being arranged to be coupled to the object such that the internal barrel of the body member may be provided in fluid communication with an interior of the object; and a piston, the piston being slidable within the barrel of the body member along a longitudinal axis of the piston, wherein the body member is rotatably coupled to the base such that the body member may be rotated with respect to the base about a first body member rotation axis that is non-parallel to the longitudinal axis of the piston. It is to be understood that by the term non-parallel is meant non-parallel and non-coaxial. By non-coaxial is meant that the axes are not directly coincident with one another along their respective lengths. The axes may be non-parallel and non-intersecting or non-parallel but with a point of intersection. It is to be understood that apparatus according to embodiments of the present invention may allow a conduit to be introduced into an object such as a pressurised pipeline or vessel through a piston by sliding the first end of the piston through an opening in an object such as a pipe, vessel or fitting coupled thereto in order to deliver the conduit to the internal volume of the object. In some embodiments, this may permit an inspection camera to be introduced into the object such as a gas storage or transport pipe or vessel under pressure without disturbing substantially a pressure of gas within the pipe or vessel. Embodiments of the present invention have the advantage that a conduit may be introduced into an object such as a pressurised pipeline or vessel through a piston by sliding the piston, the piston having a passageway therethrough, such that at least a portion of the piston passes through an opening in an object such as a pipe, vessel or fitting coupled thereto in order to deliver the conduit to the internal volume of the object. In some embodiments, this may permit an inspection camera to be introduced into the object such as a gas storage or transport pipe or vessel under pressure without disturbing substantially a pressure of gas within the pipe or vessel. Embodiments of the invention may allow a direction of travel of the conduit within the object to be controlled by appropriate rotation of the body member. This feature facilitates a reduction in damage to the conduit and / or object due to contact between the conduit and object as the conduit is fed into the object. For example, an object inspection device such as a camera, for inspecting the object, may be fed into the object by means of the present apparatus. The inspection device may be provided at one end of the conduit, and introduced into the object by axial sliding of the piston. The inspection device may be fed within the object by a user, for example along a pipeline, by feeding the conduit through the conduit orifice of the apparatus. The piston may be a hollow piston, the hollow providing the passageway for the conduit to pass through. It is to be understood that, in the case that the object is a pipeline such as a pipeline carrying pressurised gas such as pressurised natural gas, sliding contact between the conduit and pipeline may take place. By providing apparatus with the capability to rotate the body member as described, the direction in which the conduit is fed within the apparatus may be controlled, reducing an angle of incidence with which the inspection device and, subsequently, the conduit, contacts a sidewall of the pipeline. This may reduce an amount of damage suffered by the inspection device, conduit and / or pipeline sidewall as the conduit is fed into the pipeline. In some embodiments, the fact that an operator can rotate the body member with respect to the base in the manner described above enables the operator to feed a conduit into an object such as a pressurised pipeline, when the operator would be otherwise unable to do so due to a configuration of the object such as a pipe or vessel, or fitting coupled thereto. Optionally, the body member is rotatably coupled to the base for rotation about the first body member rotation axis by means of a first body member support portion. Optionally, the longitudinal axis of the piston and the first body member rotation axis intersect the first body member support portion at respective spaced apart locations. Optionally, the longitudinal axis of the piston and the first body member rotation axis intersect the first body member support portion at a common location. Optionally, the first body member support portion is rotatably coupled to the base by means of a second body member support portion, the second body member support portion being arranged to be rotatable with respect to the base about a second body member rotation axis that is non-parallel to the first body member rotation axis. This feature has the advantage that the longitudinal axis of the piston (120) may be further rotated about an axis non-parallel thereto in order to facilitate access by the piston (or element extending therefrom such as a conduit) to an interior of the object to be inspected or otherwise accessed. Optionally, the second body member rotation axis is also non-parallel to the longitudinal axis of the piston. Optionally, the body member is constrained to be rotatable about the first body member rotation axis through an arc of rotation that is less than 360 degrees. It is to be understood that mechanical constraints, such as a thickness of the first body member support portion and / or the base, may limit the range of rotation of the body member about the first body member rotation axis. Typically, the greater the angle between the longitudinal axis of the piston and the first body member rotation axis, the smaller the allowable angle of rotation may be, depending on the shape of the base and first body member support portion. It is to be understood that one or both of these components may be tapered in cross-section in order to accommodate a given arc of rotation for a given weight of material. Optionally, the body member is constrained to be rotatable about the first body member rotation axis through an arc of rotation that is in the range from 30 degrees to 330 degrees. Optionally, the piston is provided with a passageway therethrough, through which a conduit such as a cable may be passed. Optionally, the piston is substantially hollow. In an aspect of the invention there is provided an apparatus according according to a preceding aspect in combination with a conduit. Optionally, the conduit passes through the apparatus via the passageway provided through the piston. Optionally, the conduit comprises a cable, such as an electrical cable, a fibre optic cable, a mechanical cable such as a Bowden cable, or any other suitable cable. In a further aspect of the invention there is provided apparatus according to a preceding aspect coupled to an access port for accessing an asset, optionally a pipeline, optionally a storage tank. In an aspect of the invention there is provided a method of accessing an interior of an object such as a pressurised pipe or the like, comprising providing apparatus having: a body member having an internal barrel; a base, the base being arranged to be coupled to the object such that the internal barrel of the body member may be provided in fluid communication with an interior of the object; and a piston, the piston being slidable within the barrel of the body member along a longitudinal axis of the piston towards the object by axial translation of the piston, wherein the body member is rotatably coupled to the base such that the body member may be rotated with respect to the base about a first body member rotation axis that is non-parallel to the longitudinal axis of the piston, the first body member rotation axis having non-zero directional components both parallel to and orthogonal to the longitudinal axis of the piston. 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 shows apparatus according to an embodiment of the invention; FIGURE 2 illustrates schematically a geometrical relationship between a body tube, piston, base and body member support portion of the apparatus of FIG. 1 in (a) first and (b) second rotational configurations; FIGURE 3 corresponds to FIG.2 but shows the base and body member support portion in a tapered form; FIGURE 4 is a side view of the apparatus of FIG. 1 in a rotational configuration similar to that illustrated in FIG. 3(b); FIGURE 5 is a view of the apparatus showing the base in the rotational configuration of FIG. 4 showing an underside of the base; FIGURE 6 is a further view of the apparatus in the rotational configuration of FIG. 4; FIGURE 7 is a side view of the apparatus of FIG. 1 in the rotational configuration similar to that illustrated in FIG. 3(a); FIGURE 8 is a view of the apparatus in the rotational configuration of FIG. 7 showing an underside of the base; FIGURE 9 is a view of the arrangement shown in FIG. 3(b) with the piston in a deployed position in which the piston has been slid into an opening in the pipeline P to be accessed; FIGURE 10 diagrammatically illustrates a close-up sectional view of a seal unit of the apparatus of FIG. 1; FIGURE 11 illustrates a camera module suitable for use with the apparatus of FIG. 1; FIGURE 12 illustrates a seal suitable for use with the seal unit of FIG. 10; FIGURE 13 illustrates apparatus having dual nested body member support portions; FIGURE 14 shows the apparatus of FIG. 13 with the first body member support portion rotated through an angle of 90 degrees in an anti-clockwise direction as viewed in the direction of arrow X; FIGURE 15 shows the apparatus of FIG. 1 coupled to an access port P of a pipeline P’, where the apparatus is shown (a) in the rotational configuration illustrated in FIG. 2, with the piston is in a fully retracted position, (b) in the configuration shown in (a) but with the piston slid axially towards an access port such that a second end of the piston passes through the access port and into a pipeline, and (c) following rotation of the body member support portion to the rotational configuration of FIG. 3(b). DETAILED DESCRIPTION A first embodiment of apparatus according to the present invention is shown in FIG 1. The apparatus 101 has major components comprising a hollow body member or body 110 and a hollow piston 120 having first and second ends 121. The body 110 has an internal barrel within which the piston 120 is movable axially. The body 110 has a base 110B at one end thereof that is attached to a cylindrical body tube 110C of the body 110. The body tube 110C is fixedly coupled to the base 110B via body member support portion 110SP1. The body member support portion 110SP1 is rotatable with respect to the base 110B about a body member rotation axis 110R1 that is non-parallel to the longitudinal axis 120A of the piston 120 as illustrated in FIG. 1. FIG. 2(a) illustrates schematically the geometrical relationship between the body tube 110C, piston 120, base 110B and body member support portion 110SP1. The components are shown in cross-section in FIG. 2. The body tube 110C, in the form of a hollow cylinder is shown fixedly connected to the body member support portion 110SP1, which is in the form of a solid disc in the illustration of FIG 2. In the illustration shown, the body tube 110C passes through the body member support portion 110SP1 from one side to the other, forming a bore through the body member support portion 110SP1. The body member support portion 110SP1 is rotatable about an axis 110R1 thereof that is coincident with a radial centre of the disc defined by the body member support portion 110SP1. The piston 120 is slidable along, and rotatable about, a longitudinal axis 120A of the piston. The piston 120 is slidable within the body tube 110C by means of a seal pack 110CS having a pair of axially spaced ‘O’ rings that provide a slidable seal between the piston 120 and body tube 110C. The seal pack 110CS is sufficiently gas tight to prevent any substantial amount of pressurised gas from leaking from within the environment within the body tube 110C, which is arranged to be provided in fluid communication with the object to which the apparatus 101 is intended to be connected, such as a pipeline P as shown in FIG. 3(b). As shown in FIG. 2(a), the longitudinal axis 120A of the piston and the axis 110R1 of the body member support portion 110SP1 intersect at a location spaced from the body member support portion 110SP1 at an angle A. In the present embodiment the angle A is 10 degrees although other values may be useful. FIG. 2(b) shows the components of FIG. 2(a) but with a thickness of the body member support portion 110SP1 increased such that an upper surface 110SP1U of the body member support portion 110SP1 is no lower than an upper surface 110BU of the base 110B at any point. This feature has the advantage of reducing accumulation of dirt or debris in a hollow otherwise defined by the apparatus 101 if this was not the case. FIG. 3(a) shows the arrangement of FIG. 2(a) with the body member support portion 110SP1 and base 110B tapered in thickness to correspond to the tapering thickness of the body member support portion 110SP1. In FIG. 3(a) the components are shown in the same rotational configuration as that in FIG. 2., i.e., with a longitudinal axis 120A of the piston 120 substantially parallel to a cylinder axis of an access port 5 to which the base 110B is arranged to be coupled, the access port 5 being illustrated schematically in FIG. 3(b). FIG. 3(b) shows the components coupled to an access port 5 of a pipeline P and in a different rotational configuration to that of FIG. 3(a). In FIG. 3(b) the body member support portion 110SP1 is shown rotated through an angle of 90 degrees in an anti-clockwise direction as viewed in the direction of arrow X of FIG. 3(b). In the orientation shown, the longitudinal axis 120A of the piston 120 lies directly behind the body member rotation axis 110R1. It is to be understood that, with the body member support portion 110SP1 in the rotational configuration of FIG. 3(b), conduit 7 fed through the piston 120 and emerging from the second end 122 of the piston 120 will tend to be directed in the direction of arrow C of FIG. 3(b), which is partially out of the plane of the figure, towards the reader. FIG. 4 is a side view of the apparatus 101 shown in FIG. 1 in the rotational configuration illustrated in FIG. 3(b). FIG. 5 is a view of the apparatus 101 in the rotational configuration of FIG. 4, showing an underside of the base 110B. As may be seen in FIG. 5, the second end 122 of the piston 120 has an egress port 120P to permit conduit 7 (shown superimposed on the figure) to pass out from the apparatus 120 and into the pipeline P or other object with which the apparatus 101 is in fluid communication. The port 120P includes a hole (or aperture or orifice) defined by a wall of the piston 120 at the second end 122 of the piston 120. The piston 120 is provided with a guide element 120G at the second end 122 through which the conduit 7 passes in order to guide egress of the conduit 7 from the piston 120. The conduit 7 is able to slide through an aperture or orifice that is formed through the guide element 120G, in sliding contact with the guide element 120G, as conduit 7 exits the piston 120. In the present embodiment, the guide element 120G is provided with an external screw thread at one end that may be coupled to the second end 122 of the flexible finger 120 by screwing into a corresponding threaded bore provided at the second 122 of the piston 120. In the present embodiment, the base 110B, body tube 110C, piston 120, and body member support portion 110SP1 are formed from a stainless-steel material although other materials, such as aluminium or an aluminium alloy, may be useful for forming one or more of these components in some embodiments. The guide element 120G has a rounded inner surface 120GR at the free end of the guide element 120G where an inner bore of the guide element 120G terminates in order to reduce damage to the conduit 7 as it slides out from the guide element 120G. In some embodiments the guide element 120G is formed from the same or a similar material to the piston 120, such as a stainless-steel. In some alternative embodiments the guide element 120G is formed from a material that is softer than the material from which the piston 120 is formed, in order to reduce damage due to sliding contact between the piston 120 and conduit 7 as the conduit 7 emerges from the second end of the piston 120. In some embodiments the guide element 120G is formed from a plastics material, in some embodiments polytetrafluoroethylene (PTFE). However, other materials may also be useful such as Delrin (RTM), Nylon or a hardened steel. It is to be understood that the guide element 120G may be readily replaced when it becomes worn by unscrewing the worn guide element 120G. FIG. 6 is a further side view of the apparatus in the rotational configuration of FIG. 4, illustrating a length of conduit emerging from the second end 122 of the piston 120. FIG. 7 is a side view of the apparatus 101 of FIG. 1 in the rotational configuration illustrated in FIG. 3(a). FIG. 8 is a view of the retriever apparatus in the rotational configuration of FIG. 7 showing an underside of the base 110B. The base 11 OB is configured to allow attachment of the apparatus 101 to a pipe fitting 5, which is in turn fitted onto a pipeline P. In the embodiment illustrated, the base 110B is provided with circumferential thread portions 110S protruding radially from outer radial edges thereof, configured to be screwed to corresponding formations in the pipe fitting 5. An ‘O’ring element 110R is provided around an outer circumference of the base 110B to form a gas-tight seal to the pipe fitting 5. As described above with respect to FIG. 2, the body tube 110C has a seal pack 110CS that provides a gas tight seal between the body 110 and piston 120. The apparatus 101 has a seal unit 170 shown in FIG. 10 (see below) provided at the first end 121 of the piston 120 in order to provide a seal between the piston 120 and conduit 7. The seal unit 170 enables conduit 7 to be fed into the apparatus 101 by sliding through the seal unit 170 whilst the internal volume of the apparatus 101 is in fluid communication with the pipeline P. In the present embodiment, the outer diameter of the piston 120 is smaller than that of the inside diameter of the body tube 110C, to allow the piston 120 to be provided within the body tube 110C. In the present embodiment, the inner and outer diameters of the piston 120 are 40mm and 50mm, respectively, whilst the inner and outer diameters of the body tube 110C are 60mm and 70mm, respectively. Other values of inner and outer diameters of the piston 120 and body tube 110C may be useful. In some embodiments the outer diameter of the piston 120 may be in the range from around 10mm to around 100mm. Other values of diameter may be useful in some embodiments. The apparatus 101 is arranged to allow the piston 120 to be moved between a retracted condition, shown in FIG. 3(b), and a deployed condition shown in FIG. 9, by axial sliding of the piston 120. In the retracted condition of the apparatus 101, a valve 5V (shown in dashed outline) may provide a seal between the apparatus 101 and internal environment of the pipe P, allowing removal and fitment of the apparatus 101 to the access port 5. As noted above, the piston 120 is hollow, defining a passageway therethrough to permit a length of conduit 7 to pass from the head 170, via the piston 120 into the pipeline P. Seal unit The seal unit VOA is illustrated in enlarged view in FIG. 10. The seal unit 170 has a cylindrical body portion 170C formed from a stainless-steel material, the body portion 170C having first and second opposite ends 171, 172 axially spaced from one another. The body portion 170C is coupled at its second end 172 to the first end 121 of the piston 120 by means of a threaded bore 1706 provided at the second end 172 of the seal unit 170 and a corresponding external screw thread provided on the first end 121 of the piston 120. The body portion 170C has a pair of handles 170H proximate the second end 172 of the body portion 170C to facilitate manual manipulation of the piston 120 by a user. A pin element 170P protrudes radially from the seal unit 170 proximate the second end 172 of the body portion 170C a sufficient distance to allow the seal unit 170 to form a bayonet-type coupling to the body 110. The pin element 170P engages with corresponding arms 110HA of the head 110H to form the bayonet-type coupling, This coupling enables the piston 120 to be locked in a substantially fixed axial position with respect to the body 110 once the piston 120 has been introduced into the object such as an access port 5 or pipeline P. The apparatus 101 is provided with a cap member 175C in the form of a cylinder having an external thread. The cap member 175C has a pair of handles 175H at a first end to facilitate screwing of a second, opposite end of the cap member 175C into an internal threaded bore formed in the first end 171 of the body portion 170C. The second end of the cap member 175C provides a pressure bearing portion 175CB that is arranged to apply pressure to a first sealing means 174S in the form of a compliant elastic plug seal 174S that fits snugly within the bore of the body portion 170C of the seal unit 170. The plug 174S has an axial passageway 174SP therethrough to facilitate passage of the conduit 7 therethrough. In the present embodiment the plug 174S is formed from an elastomeric material, in the present embodiment a natural rubber, although other materials may be useful such as synthetic rubber, a foam material, polyurethane, silicone or any other suitable material. Thus, it is to be understood that the cap member 175C provides an adjustable clamping mechanism for varying the pressure applied to the seal 174S, to vary the pressure between seal 174S, the body portion 170C and the conduit 7. This in turn varies an amount of frictional force opposing sliding of the conduit into and out from the apparatus 101. In some embodiments, the cap member 175C is formed in two diametrically opposite halves that, when brought together, form a barrel around the conduit 7 before the cap member 175C is screwed into the first end 171 of the body portion 170C. It is to be understood that, with the conduit 7 disposed substantially coaxially through the seal unit 170, rotation of the cap member 175C to screw the cap member 175C into the body portion 170C causes the pressure bearing portion 170CB to contact the first seal 174S and apply axial pressure thereto, compressing the seal axially against a seat or shoulder 170CS formed in the body portion 170C and preventing further axial movement of the seal 174S. Compression of the seal 174S causes radial expansion of the seal 174S due to the Poisson effect, compressing the seal 174S radially between the conduit 7 and body portion 170C of the seal unit 170. The feature that the cap member 175C may be screwed onto the body portion 170C of the seal unit 170 allows the seal 174S to be replaced or cleaned more conveniently. A pair of handles 175H are provided on diametrically opposite sides of the cap member 175C to allow the cap member 175C to be screwed onto the body portion 170C to compress the first seal 174S. A second sealing means 176S is provided in the form a compliant elastic plug seal 176S that fits snugly within a bore of the cap member 175C of the seal unit 170 as shown in FIG. 10. The second seal 176S has an axial passageway therethrough to facilitate passage of the conduit 7 therethrough and provides a seal between the conduit 7 and cap member 175C and external atmosphere. The second seal 176S is formed from the same or similar elastomeric material to the first sealing means 174S. The purpose of the second seal 176S is to prevent egress from the apparatus 101 of any gas that leaks past the first seal 174S. Payload FIG. 11 shows a camera module 180 suitable for attachment to the conduit 7 at the free end of the conduit 7 that emerges from the piston 120. The camera module 180 has a body 184 and a head 182 rotatably coupled to the body 184. The head carries a camera unit, the camera unit including a lens and image sensor. The camera may be any suitable camera such as a digital or analogue camera. In the present embodiment the image sensor of the camera is a CMOS (complementary metal oxide semiconductor) image sensor although other sensors may be useful such as one or more CCD (charge coupled device) sensors. The head 182 is arranged to be rotatable about an axis normal to a longitudinal axis L of the body 184 as indicated by arrow A in FIG. 11. In the position shown in FIG. 11 the head 182 is rotated slightly anticlockwise with respect to a forward-looking orientation, the forwardlooking orientation being an orientation in which the camera unit within the head 182 is arranged with its optic axis substantially coincident with and along the longitudinal axis (cylinder axis) L of the body 184. In the present embodiment the head 182 is rotatable by around 30 degrees clockwise and 30 degrees anticlockwise with respect to the forwardlooking orientation, about an axis normal to the longitudinal axis L of the body 184. Other angular ranges of rotation may be useful in some embodiments. In some embodiments the head 182 may be substantially fixed and not rotatable with respect to the body 184. In some embodiments the camera may be provided within the body 184 with no head 182 provided. In the embodiment shown, the head 182 has a light source (not shown) comprising an array of light emitting diodes position around a lens of the camera unit. It is to be understood that the camera module 180 may be sized to allow the camera module 180 to be withdrawn, by withdrawal of the piston 120, within the body tube 110C of the apparatus 101. The conduit 7 is flexible, but is sufficiently rigid to enable it to be pushed along pipework without unduly buckling. The conduit 7 runs from the back of the body 184 of the camera module 180, through the guide element 120G, piston 120 and seal unit 170, emerging from the seal unit 170 to ambient atmosphere through conduit orifice 176SA, and on to a spool (not shown). The conduit 7 contains internal wiring that carries a power signal to power the camera module 180, including the light source, and also carries a video signal generated by the camera module 180 that may be viewed or recorded by suitable equipment. In the present embodiment, the apparatus 101 is suitable for use with conduit 7 having a diameter in the range of approximately 3-20mm according to the application with which it is to be used, although other diameters may be useful. It is to be understood that a suitable sized guide element 120G and first and second seals 174S, 176S may be selected according to the chosen conduit diameter so as to form a suitably gas-tight seal. It is to be understood that other payloads may be employed in addition to or instead of a camera such as water extraction tooling. In some embodiments the conduit 7 may have a hollow portion such as a hollow core in addition to or instead of electrical and / or optical cabling for allowing fluid flow from within a pipeline P or other object to a reservoir external to the apparatus 101. This may allow extraction of liquid such as water from within a pipeline P or other object. Seal In the embodiment of FIG. 1, a compliant elastic plug seal 174S is provided as noted above and shown in FIG. 10, that fits snugly within the bore of the body portion 170C of the seal unit 170, the seal 174S being compressed by the cap member 175C that provides an adjustable clamping mechanism for varying the pressure applied to the seal 174S, to vary the pressure between seal 174S, the body portion 170C and the conduit 7. In the embodiment of FIG. 1 the plug seal 174S is a unitary component in the form of a hollow cylinder having a longitudinal cut through a wall thereof parallel to a cylinder axis of the seal 174S. FIG. 12(a) illustrates a seal 674S according to an alternative embodiment, for use in embodiments of the present invention. The seal 674S comprises a compliant elastic material 640 as its main sealing component, which is a foam rubber cylindrical block 640 in this embodiment. On either end of the foam rubber block sits a layer of thin rubber sheet 641, 64T, and forming the end blocks of the seal are a pair of nylon end caps 642, 642’. The end caps 642, 642’ each provide a resilient surface able to withstand pressure applied by the cap member 175C as described in relation to FIG. 10, and countered by the seat or shoulder 1708 formed in the body portion 170C. An orifice 674SP runs through each component and is adapted to house the conduit 7, and defines an axis of the seal 674S. As an axial pressure is applied to the seal 674S in use, the end caps 642, 642’ transmit force to the foam rubber block 640, compressing it. As the block 640 compresses axially, it will tend to push outwards in the plane orthogonal to the axis as a consequence of the Poisson effect. Thus, it will push against the conduit 7 and sidewall of the body portion 170C, providing, within design limits, a better seal as the axial force is increased. The foam block 640, rubber layers 641, 641’ and end caps 642, 642’ are separate components in the present embodiments, being assembled together when required, for example in the field. Each is provided with means for allowing their fitting around a conduit. FIG. 12(b) shows an end cap 742 similar to end cap 642 of the embodiment of FIG. 12(a) that has been disassembled allowing it to be fitted to a conduit. The end cap comprises a generally circular (in assembled configuration) disk that has a generally “T” shaped piece 743 arranged to be slidably inserted or removed from the remaining portion 744. Web portions 745, 745’ on sliding piece 743 are adapted to engage with corresponding slots 746, 746’ on the remaining piece 744. FIG 12(c) shows a foam rubber sealing member 740 similar to that of member 640 shown in FIG 12(a). The sealing member 740 is of a cylindrical form, with orifice 774SP, for receiving a conduit, running along the axis. A cut 740C in the foam provides access for the conduit to the orifice 741 when assembling the seal. The cut 740C runs in a generally helical path along the axis of the member 740. By having a cut path that is not purely axial, the surface area of the cut region is increased, which acts to increase the length of any leakage path that may exist when the seal is assembled and in-situ in an embodiment of the invention. Also, axial pressure on the sealing member 740 will act to push the cut portions together in such an embodiment, improving the seal performance, whereas this would not occur if the cut ran straight down the axis of the member 740 as shown by dashed line 740C’. Double rotational embodiment FIG. 13 is a schematic cross-sectional illustration of a geometrical configuration of apparatus 201 according to a second embodiment of the present invention. Like features of the embodiment of FIG. 13 to those of the embodiment of FIG. 1 are shown with like reference signs incremented by 100. The apparatus 201 has major components comprising a hollow body member or body 210 that includes a cylindrical body tube 210C and a hollow piston 220 that are similar to those of the embodiment of FIG. 1. As in the embodiment of FIG. 1, the body 210 has an internal barrel within which the piston 220 is movable axially along a longitudinal axis 220A of the piston 220, which is coaxial with a longitudinal axis of the body tube 210C. The body 210 has a base 210B at one end thereof that is coupled to the body tube 210C. The body tube 210C is coupled to the base 210B via first and second body member support portions 210SP1, 210SP2. The base 210B and first and second body member support portions 210SP1, 210SP2 are in the form of nested discs in the embodiment shown. The body tube 210C is fixedly coupled to the first body member support portion 210SP1, being the radially innermost disc. The first body member support portion 210SP1 is rotatably coupled to the second body member support portion 210SP2 such that the first body member support portion 210SP1 is rotatable about a first body member rotation axis 210R1. The second body member support portion 210SP2 is in turn rotatably coupled to the base 210B, within which the second body member support portion 210SP2 is nested, such that the second body member support portion 210SP2 is rotatable about a second body member rotation axis 210R2. A radially outer surface 210SP2R of the second body member support portion 210SP2 defines a cylinder, mutually parallel dashed lines 210R2’ in FIG. 13 being extensions of the radially opposite edges of said cylinder. It is to be understood that the first body member rotation axis 210R1, second body member rotation axis 210R2 and the longitudinal axis 220A of the piston 220 are mutually nonparallel, as illustrated in FIG. 13. The purpose of the arrangement is to permit the piston 220 to be manipulated such that the longitudinal axis 220A of the piston 220 is rotated to an angle to permit sliding of the piston 220 sufficiently towards, optionally into, an object such as a pipeline P or access port 5 coupled to the object, to permit a task such as inspection of the object to be performed. As shown in FIG. 13, the longitudinal axis 220A of the piston and the first body member rotation axis 210R1 of the body member support portion 210SP1 intersect at a point X1 spaced from the first body member support portion 210SP1, at an angle A, point X1 being below the apparatus 201 in the orientation shown in FIG. 13, i.e., on an object side of the apparatus 201 rather than an ambient pressure side, the ambient pressure side being the side from which conduit 7 is fed through the apparatus 201. In the present embodiment the angle A is 10 degrees although other values may be useful. Similarly, the first body member rotation axis 210R1 of the first body member support portion 210SP1 and the second body member rotation axis 210R2 of the second body member support portion 210SP2 intersect at a point X2 spaced from the second body member support portion 210SP1, at an angle A, point X2 being below the apparatus 201 in the orientation shown in FIG. 13, i.e., on the object side of the apparatus 201 rather than the ambient pressure side. In the embodiment shown, the point X2 is below the point X1 in the orientation shown, i.e. further from the apparatus than point X1. In some alternative embodiments, point X2 may be substantially coincident with point X1. In some further alternative embodiments, point X2 may be above point X1, i.e. closer to the apparatus 201 than point X1. FIG. 14 shows the apparatus 201 with the first body member support portion 210SP1 rotated through an angle of 90 degrees in an anti-clockwise direction as viewed in the direction of arrow X, relative to the orientation shown in FIG. 13. The second body member support portion 210SP2 is in substantially the same rotational position in FIG. 14 as in FIG. 13. In the orientation shown in FIG. 14, the longitudinal axis 220A of the piston 220 lies directly behind the first body member rotation axis 210R1 and therefore appears coincident therewith in the view shown in FIG. 14. It is to be understood that, with the first body member support portion 210SP1 in the rotational configuration of FIG. 14, conduit 7 fed through the piston 220 and emerging from the second end 222 of the piston 220 will tend to be directed in the direction of arrow C of FIG. 14, which is partially out of the plane of the figure, towards the reader. It is to be understood that the relative thicknesses and cross-sectional shapes of the base 210B and first and second body member support portions 210SP1, 210SP2 may be set according to the desired ranges of angular rotation of the first and second body member support portions 210SP1, 210SP2 in order to prevent gaps forming between components. The thickness of one or more of the base 210B and first and second body member support portions 210SP1, 210SP2 may be tapered in some embodiments in order to achieve this. Tapering may be employed to reduce a risk of accumulation of dirt and debris in some embodiments. It is to be understood that a mass of the apparatus 201 may also be reduced by appropriate choice of thickness of these components. As in the embodiment of FIG. 1 and as shown in FIG. 13 and FIG. 14, the body tube 210C passes through the body member support portion 210SP1 from one side to the other, forming a bore through the body member support portion 210SP1. The first body member rotation axis 210R1 is coincident with a radial centre of the disc defined by the body member support portion 210SP1. It is to be understood that, in the embodiment of FIG. 13 and 14, with the first and second body member support portions 210SP1, 210SP2 in the configuration shown in FIG. 13, the longitudinal axis 220A of the piston 220 is substantially parallel to a cylinder axis of the cylindrical access port 5 to which the base 210B is shown to be coupled in FIG. 13. FIG. 15 shows the apparatus 101 of FIG. 1 coupled to an access port P of a pipeline P’. In the configuration shown in FIG. 15(a) the apparatus 101 is in the rotational configuration illustrated in FIG. 2 and the piston 120 is in a fully retracted position. FIG. 15(b) shows the apparatus 101 in a configuration in which the piston 120 has been slid axially towards the access port P such that the second end 122 of the piston 120 has passed through the access port P and into the pipeline P’. FIG. 15(c) shows the apparatus 101 following rotation of the body member support portion 210SP1 to the rotational configuration of FIG. 3(b). Conduit 7 (FIG. 6, FIG. 10) can now be fed through the apparatus 101 causing (in the arrangement shown) the camera module 180, that is coupled to the free end of the conduit 7 in the arrangement shown (although other devices and apparatus may be coupled thereto instead), to travel along the pipe P’. The camera module 180 permits inspection of the interior of the pipe P’. Throughout the description and claims of this specification the apparatus has been described in the sense of it being operated in an upright, vertical manner, with the head at the top, and the base at the bottom, with the words, “upper” and “lower”, “up” and “down” etc. being used in this context. This is purely for convenience of explanation, and it will be appreciated by a normally skilled person that the apparatus may be employed in various orientations according to particular requirements. 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. 5 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. 10 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. 15

Claims

1. An apparatus (101) for providing access to an interior of an object (P) such as a pressurised pipe (P) or the like, the apparatus comprising:a body member (110) having an internal barrel;a base (110B), the base (110B) being arranged to be coupled to the object (P) such that the internal barrel of the body member (110) may be provided in fluid communication with an interior of the object (P); anda piston (120), the piston (120) being slidable within the barrel of the body member (110) along a longitudinal axis (120A) of the piston (120) towards the object (P) by axial translation of the piston (120),wherein the body member (110) is rotatably coupled to the base (110B) such that the body member (110) may be rotated with respect to the base (110B) about a first body member rotation axis (110R1) that is non-parallel to the longitudinal axis (120A) of the piston (120), the first body member rotation axis (110R1) having non-zero directional components both parallel to and orthogonal to the longitudinal axis (120A) of the piston (120).

2. An apparatus (101) according to claim 1 wherein the body member (110) is rotatably coupled to the base (110B) for rotation about the first body member rotation axis (110R1) by means of a first body member support portion (110SP1).

3. An apparatus (101) according to claim 2 wherein the longitudinal axis (120A) of the piston (120) and the first body member rotation axis (110R1) intersect the first body member support portion (110SP1) at respective spaced apart locations.

4. An apparatus (101) according to claim 2 wherein the longitudinal axis (120A) of the piston (120) and the first body member rotation axis (110R1) intersect the first body member support portion (110SP1) at a common location.

5. An apparatus (201) according to any one of claim 2 to 4 wherein the first body member support portion (110SP1) is rotatably coupled to the base by means of a second body member support portion (110SP2), the second body member support portion (110SP2) being arranged to be rotatable with respect to the base (110B) about a second body member rotation axis (110R1) that is non-parallel to the first body member rotation axis (110R1).

6. An apparatus (201) according to claim 5 wherein the second body member rotation axis (110R1) is also non-parallel to the longitudinal axis (120A) of the piston (120).

7. An apparatus (101, 201) according to any one of claims 2 to 6 wherein the body member (110) is constrained to be rotatable about the first body member rotation axis (110R1) through an arc of rotation that is less than 360 degrees.

8. An apparatus (101, 201) according to claim 7 wherein the body member (110) is constrained to be rotatable about the first body member rotation axis (110R1) through an arc of rotation that is in the range from 30 degrees to 330 degrees.

9. An apparatus (101, 201) according to any preceding claim wherein the piston (120) is provided with a passageway therethrough, through which a conduit (7) such as a cable (7) may be passed.

10. An apparatus (101, 201) according to claim 9 wherein the piston (120) is substantially hollow.

11. An apparatus (101, 201) according to claim 9 or claim 10 in combination with a conduit (7).

12. An apparatus (101, 201) according to claim 11 wherein the conduit (7) passes through the apparatus via the passageway provided through the piston (120).

13. An apparatus (101, 201) according to any one of claims 9 to 12 wherein the conduit comprises an electrical cable or a fibre optic cable.

14. An apparatus (101, 201) according to any preceding claim coupled to an access port for accessing an asset, optionally a pipeline, optionally a storage tank.

15. A method of accessing to an interior of an object (P) such as a pressurised pipe (P) or the like, comprising providing apparatus (101, 201) having:a body member (110) having an internal barrel;a base (110B), the base (110B) being arranged to be coupled to the object (P) such that the internal barrel of the body member (110) may be provided in fluid communication with an interior of the object (P); anda piston (120), the piston (120) being slidable within the barrel of the body member (110) along a longitudinal axis (120A) of the piston (120) towards the object (P) by axial translation of the piston (120),wherein the body member (110) is rotatably coupled to the base (110B) such that the body member (110) may be rotated with respect to the base (110B) about a first body member rotation axis (110R1) that is non-parallel to the longitudinal axis (120A) of the piston (120), the first body member rotation axis (110R1) having non-zero directional components5 both parallel to and orthogonal to the longitudinal axis (120A) of the piston (120).

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