Field of the Invention

The present invention relates to an apparatus and method for retrieving components from fluid carrying pipelines, and in particular from pipelines carrying pressurised fluids.

Background of the Invention

The present invention relates to pipelines, and more particularly to an apparatus and method for extracting components of pipelines, such as stop valves for controlling fluid flow through pipelines, whilst the pipeline is under pressure. For example, pipelines such as subterranean or over ground pipes for fluid flow, e.g. water and gas pipes.

There are many miles of water and gas pipelines located underground in the UK, and indeed elsewhere in the world. Valves are located at many points along these pipelines, to enable control of the flow of fluid through sections of the pipelines adjacent the valves. For example, many large diameter pipes are located deep underneath roadways, from which smaller diameter pipes branch off, each leading to separate industrial, commercial or residential properties to supply them with e.g. tap water or other non-treated forms of water. Should there be a water leak at one of these properties, a valve in the branch pipe to that property can be operated to stop the flow of water from the large diameter main pipe to the residence along the branch pipe.

These valves can take one of many forms, but essentially each has some sort of internal barrier member, such as a gate, a ball, a plug, or a disc (in the case of a butterfly valve), which is moveable to allow, to restrain, or to stop the flow of fluid through the valve. Such barrier members are usually moved by rotating a spindle which extends from the barrier member to the exterior of the valve, towards the ground level above the valve. To operate one of these subterranean valves, an operative feeds a tool, e.g. tee-bar, valve key down an open shaft from ground level, which open shaft extends down to the valve. The operative aims to locate the end of their key on an e.g. tapered or shaped shank on the end of the spindle. Then, by rotating the key, the spindle is turned, thus moving the barrier member of the valve, to block or unblock the channel in the valve through which the fluid flows. Alternatively, the spindle of the valve may extend the majority of the way up the open shaft from the valve to the ground surface, allowing the service engineer to use a short key on the end of the long spindle to operate the valve.

In either case, such an open shaft cannot be left open to the elements since such an opening in a footpath or roadway poses a significant danger to pedestrians and drivers, etc. Thus, a cover plate is located in the roadway or footpath above the valve to cover the open shaft. As these cover plates usually need to withstand the weight of traffic passing over them, including heavy goods vehicles, it is preferred to make the cover plates as small as possible. Small cover plates need not be made as robust as larger ones to withstand the same mass.

Of course, these valves require maintenance, for example to replace a part of the closing mechanism of the valve after it becomes worn or damaged. In known pipelines, once the section of pipeline in which a valve is located is isolated from the rest of the pipeline network (perhaps by closing valves upstream and downstream of the valve in question), or the pipeline is depressurised, the valve can be serviced. Conventional valves have a removable 'bonnet' on their upper side (the term 'upper' is used here with reference to the relative orientation of the valve to the road surface above) which is held onto the main casing of the valve by a number of bolts to cover an access chamber in the valve. In many valves, once the bonnet has been removed, the closing mechanism of the valve can be accessed and removed for such servicing. In some cases the closing mechanism is of a closed-type, such as a plug valve, but such a valve still requires the removal of the outer bonnet to access the plug.

In order to be able to remove such a bonnet, a service engineer must be able to access the valve itself. Since the valves in question are located deep underground, e.g. 2 to 15 feet (0.6m to 4.5m) below ground level, this is not possible from the road surface. Also, the cover plate in the road surface and the underlying open shaft are too narrow to allow a service engineer to climb down. Thus, maintenance on such subterranean valves can only be carried out after excavation of the earth, tarmac, etc. above the valve, which is of course time consuming, expensive and highly inconvenient to pedestrians and motorists who, as a result of such excavation, may find roads closed or partially blocked with temporary traffic control systems in operation.

There are also several types of overland (above ground) valves which require the removal of a bonnet to access an access chamber within the valve for maintenance purposes. Although not requiring excavation, as in the case of subterranean valves, such a removal of a bonnet is time consuming, and thus costly.

The Applicant has invented a pipeline apparatus where a component such as valve or monitoring apparatus and associated seals may be extracted from ground level.

It would be desirable to be able to extract and service components of pipeline apparatus without depressurizing the pipeline.

Summary of the Invention

According to the invention there is provided an apparatus as specified in Claim 1. According to another aspect of the invention there is provided a method as specified in Claim 12.

Preferred features of the invention are set out in the claims dependent on Claims 1 and 12 and in the description and drawings.

Brief Description of the Drawings

In the Drawings, which illustrate preferred embodiments of the apparatus of the invention, and which are by way of example:

Figure 1 is a side view of an apparatus according to the invention;

Figure la is a detail view of a lock mandrel of Figure 1;

Figure 2 is a cross-sectional elevation on the axis A-A of Figure 1;

Figures 3 and 3a show the apparatus shown in Figures 1 and 2 with locking keys of the lock mandrel illustrated in Figure la retracted;

Figure 4 is a side view of the apparatus illustrated in Figures 1 and 2 with a component removed therefrom;

Figure 5 is a cross-sectional elevation on the axis A-A of Figure 4;

Figure 6 is a schematic representation of components of the apparatus illustrated in Figure 1, configured for re -assembly;

Figure 7 is a schematic representation of an alternative embodiment of the invention with a valve thereof in an open condition;

Figure 8 is a schematic representation of the embodiment of the invention illustrated in Figure 7 with the valve in the closed condition; Figure 9 is a schematic representation of a component of the apparatus illustrated in Figures 7 and 8; and

Figure 10 is a schematic representation of another component of the apparatus illustrated in Figures 7 and 8.

Detailed Description of the Preferred Embodiments

Referring now to Figure 1, a component retrieval apparatus 1 comprises a collar 2 connected to one side of a valve 5 and configured to engage a housing 20 in which a component to be retrieved is situated. Another collar 9 is attached to the other side of the valve 5. One end of an elongate cylinder 8 is removably attachable to the collar 9 and is fastened in place by an outer collar 9a.

A collar 11 is removably attached to the free end of the cylinder 8, for example by corresponding threads, and includes a bore 12 through which a shaft 13 passes. The shaft 13 is attached to a frame 10, which includes a top plate 14 to which the shaft 13 is attached and ring members 15, 16 situated towards the lower end of the cylinder 8 when the shaft 13 is retracted in the cylinder. The rings 15, 16 are attached to the top plate 14 by three members 17.

A tool 3 is mounted on the other end of the shaft 13. The tool 3 engages the component to be retrieved and through manipulation of the position of the tool 3, the component may be disengaged and lifted, or lowered into engagement and locked. The shaft 13 includes a jarring tool 13a which may be used to assist in freeing off a component to which the tool 3 is attached.

The tool 3 has a free end 3a that is configured to engage with the assembly 21 in such a manner that the assembly 21 may be released from the housing 20. The detailed configuration of the tool 3 is determined by the configuration of the assembly and therefore is not described in detail. As is best shown in Figures 1, 2 and 5, the valve 5 comprises a ball valve 6 providing an opening 7 therethrough. A handle 6a is connected to the ball valve 6 so that it may be moved through ninety degrees between the open position shown in Figure 2 and the closed position shown in Figure 5.

The opening 7 is sufficiently large that the tool 3 and a lock mandrel and valve cartridge assembly 21 may pass therethrough. This valve cartridge assembly includes a shaft 4 extending therethrough.

In order to retrieve the lock mandrel and valve cartridge assembly 21, the collar 2 is attached to an upper part 20a of the housing 20 in which the assembly 21 is situated. The collar 2 is configured such that it makes a fluid tight seal with the housing 20. The ball valve 6 is opened and the tool 3 is lowered therethrough to engage the assembly 21. The cylinder 8 is brought up to the collar 9 and the tool 3 connected to shaft 12. The outer collar 9a is attached to the collar 9 to ensure a fluid tight seal between the collar 9 and the cylinder 8.

The tool 3 is manipulated so as to release lock keys 22 of the lock mandrel of assembly 21 from engagement with housing 20 as show in Figure 3a where the lock keys 22 are shown in a retracted condition, whereas in Figure la the lock keys are shown in an extended, locking, condition.

The shaft 12 is then lifted upward, pulling the tool 3 and the attached assembly 21 with it, through the opening 7 in the valve 6. The assembly 21 is extracted from the housing 20, into the cylinder 8 as shown in Figures 4 and 5. In this configuration, the cylinder 8 fills with fluid, since the pipeline to which the assembly 21 is connected is pressurised.

With the assembly 21 extracted, the valve 6 is closed. The cylinder 8 is then bled of fluid via a bleed port 18.

The assembly 21 may then be taken away for repair, with the pipeline closed off by valve 5, or a replacement assembly 21 may be re-introduce into the housing 20 immediately. The procedure for re-introducing an assembly 21 is substantially the reverse of the extraction procedure.

Starting in the configuration illustrated in Figure 5, the outer collar 9a is attached to collar 9. Ensuring that the bleed port 18 is closed, the ball valve 6 is moved to its open position so that the assembly 21 may pass therethrough.

The assembly 21 is lowered into place, the weight of the frame pressing the assembly 21 into place. The tool 3 is used to manipulate lock keys 22 to thereby lock the assembly 21 in place in the housing 20. The tool 3 is then is released from the assembly 21. The frame 10 is raised, lifting the tool 3 into the cylinder 8. The ball valve 6 is closed and the bleed port 18 opened. The outer collar 9a is then released from collar 9 so that the cylinder 8 may be removed.

The collar 2 is then removed from housing 20 and the replacement of assembly 21 is complete.

The housing 20 is a housing of a pipeline apparatus of the type described in the applicant's international patent application published under number WO2014/020358. In such apparatus the seals the prevent egress of fluid from the housing are situated between the inner surface of the housing and lock mandrel. This type of pipeline apparatus is the simplest to use with the component retrieval apparatus of the present invention, since the retrieval apparatus can be attached directly onto the housing 20. However, the apparatus and method of the present invention is not limited to use with pipeline apparatus of the type described in WO2013/020358.

Figures 7 to 10 illustrate an embodiment of the apparatus configured for use with pipeline apparatus 50 comprising a bonnet valve 52. The pipeline apparatus is of the type described in EP0045020, which provides for the quick release of the bonnet valve 52 from the housing 51. In this case quick release is achieved by using a bayonet fitting, the housing 51 and bonnet valve 52 each comprising part of the bayonet fitting, so that attachment and release of the bonnet valve 52 from/ to the housing 51 may be achieved by rotating the bonnet 52a of the bonnet valve 52 with respect to the housing.

In order for the apparatus of the invention to function with a bonnet valve, the apparatus must attach to the housing 51 of the apparatus 50 below the bonnet valve 52. This is because the bonnet valve 52 seals against the upper surface of the housing 51.

Referring in particular to Figure 9, the apparatus of the invention therefore comprises a shell clamp 55 that attaches to an outer surface of an upper part 51a of the housing 51 in a fluid tight manner. A valve 60, in the illustrated example a knife valve, is mounted onto a flange 56 of the shell clamp 55. The knife valve 60 comprises a knife 62 that is mounted so as to slide in the housing 64 when actuated by actuation wheel 61, which is attached to a shaft 63. The shaft 63 is attached to the knife 62 in such a manner that when the wheel 61 is rotated the knife 61 slides in housing 64 to open or close a fluid pathway to the chamber formed by the inner walls of the shell clamp 55. The attachment of the housing 64 of the flange 56 is made so as to forma fluid tight seal therebetween.

Figure 10 illustrates the component of the apparatus of the invention that attaches to the shell clamp and valve shown in Figure 9.

The cylinder 8 and components mounted therein are almost identical to the corresponding components illustrated in Figure 1 to 6 and hence like numerals have been used to indicate like parts.

The cylinder 8 comprises flanges 9b and 9c at the free ends thereof. The flange 9b provides for attachment of the cylinder 8 to the housing 64, for example by passing bolts through aligned holes therein. The flange 9c provides for the attachment of an end cap 11a thereto (in this example the cylinder 8 is configured with a flange 9c to receive an end cap 11a, whereas this upper end of the cylinder may be configured as shown in Figures 1 to6, with a collar 11 closing the end thereof). The end cap 11a includes a bore 12 through which a shaft 13 passes. The shaft 13 may be attached to a frame 10 as shown in Figures 1 to 6. The shaft 13 is attached to a tool 3, which may be referred to as a fishing tool. The tool 3 is attached to the shaft 13 via a jarring tool 13a.

The fishing tool 3 has a free end 3a that is configured to engage with the bonnet 52a in such a manner that the bonnet 52a may be released. The detailed configuration of the tool 3 is determined by the configuration of the bonnet and therefore is not described in detail. The shaft 13 and jarring tool 13a provide for the bonnet 52a to be disconnected from the housing 51 and hence the bonnet and valve components 56 to be withdrawn into the cylinder 8.

The mode of operation of the embodiment illustrated in Figures 7 to 10 is the same as the mode of operation described with reference to the embodiment illustrated in Figures 1 to 6.