GB2554692A

GB2554692A - Pipeline coupling

Info

Publication number: GB2554692A
Application number: GB1616826.2A
Authority: GB
Inventors: Cooper Neil; Higgins Steven; Howard Stuart
Original assignee: Gall Thomson Environmental Ltd
Current assignee: Gall Thomson Environmental Ltd
Priority date: 2016-10-04
Filing date: 2016-10-04
Publication date: 2018-04-11
Anticipated expiration: 2036-10-04
Also published as: GB2554692B; WO2018065761A1; GB201616826D0

Abstract

A pipeline coupling 20 comprises a pair of shut-off valve housings 22, 24 secured to each other via a first fastening arrangement which permits the shut-off valve housings 22, 24 to separate from each other on operation of an actuation mechanism. The shut-off valve housings 22, 24 define a hollow bore along which flowable material may flow. The coupling 20 further comprises at least one shut-off valve located within the hollow bore, the shut-off valve including a valve member 26 which moves between a valve open position and a valve closed position. The valve member 26 is biased to move to its valve closed position on separation of the shut-off valve housings 22, 24. The first fastening arrangement includes a first longitudinal fastening member 28 and a first fastening nut 30, such as a hydraulic nut. The actuation mechanism includes a driving assembly, such as a hydraulic driving assembly, which mechanically drives the first fastening nut 30 to disengage the nut 30 from the corresponding member 28. The longitudinal fastening member 28 can have a weakened portion that breaks on exposure to a tensile load exceeding a predetermined limit.

Description

(54) Title of the Invention: Pipeline coupling Abstract Title: Pipeline coupling (57) A pipeline coupling 20 comprises a pair of shut-off valve housings 22, 24 secured to each other via a first fastening arrangement which permits the shut-off valve housings 22, 24 to separate from each other on operation of an actuation mechanism. The shut-off valve housings 22, 24 define a hollow bore along which flowable material may flow. The coupling 20 further comprises at least one shut-off valve located within the hollow bore, the shut-off valve including a valve member 26 which moves between a valve open position and a valve closed position. The valve member 26 is biased to move to its valve closed position on separation of the shut-off valve housings 22, 24. The first fastening arrangement includes a first longitudinal fastening member 28 and a first fastening nut 30, such as a hydraulic nut. The actuation mechanism includes a driving assembly, such as a hydraulic driving assembly, which mechanically drives the first fastening nut 30 to disengage the nut 30 from the corresponding member 28. The longitudinal fastening member 28 can have a weakened portion that breaks on exposure to a tensile load exceeding a predetermined limit.

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PIPELINE COUPLING

The invention relates to a pipeline coupling, preferably for use as a breakaway coupling or a release coupling.

Breakaway and release couplings are known and are often used in situations where a pipeline may be exposed to a tensile loading which, in the absence of a breakaway or release coupling, could cause the pipeline to fracture. Typically such a pipeline may be one used for carrying material between two locations, e.g. between ships or between a ship and a dock. If such a fracture occurs, the material being conveyed along the pipeline flows freely out of the fractured ends of the pipeline. This can cause significant spillage that is expensive to clear and may be environmentally undesirable. The presence of a breakaway or release coupling enables the pipeline to fracture at a specified location (i.e. at the coupling) and for spillage to be avoided by providing valves in the breakaway coupling which are actuated when the coupling breaks.

According to an aspect of the invention, there is provided a pipeline coupling comprising: a pair of shut-off valve housings secured to each other via at least one first fastening arrangement, the shut-off valve housings defining a hollow bore along which flowable material may flow, the or each first fastening arrangement permitting the shut-off valve housings to separate from each other on operation of an actuation mechanism operably engaged with the or each first fastening arrangement; and at least one shut-off valve located within the hollow bore of at least one of the shutoff valve housings, the or each shut-off valve including a valve member movable between a valve open position and a valve closed position in which the valve member shuts off the flow of a flowable material through the hollow bore, the or each valve member being biased to move to its valve closed position on separation of the shut-off valve housings, wherein the or each first fastening arrangement includes a first longitudinal fastening member and a first fastening nut, the or each first fastening nut in engagement with the corresponding first longitudinal fastening member to secure the shut-off valve housings to each other, and the actuation mechanism includes a or a respective driving assembly configured to mechanically drive the or each first fastening nut to disengage the or each first fastening nut from the corresponding first longitudinal fastening member.

The provision of the first fastening nut and the first longitudinal fastening member in the or each first fastening arrangement results in a reliable means of securing the shut-off valve housings to each other and separating the shut-off valve housings from each other.

The provision of an actuation mechanism that is operable to disengage the or each first fastening nut from the corresponding first longitudinal fastening member and thereby allow the shut-off valve housings to separate from each other allows selective operation of the pipeline coupling in circumstances where it is desirable to break a pipeline. In addition the provision ofthe actuation mechanism to aid in the separation ofthe shut-off valve housings is particularly beneficial when it is difficult to access the or each first fastening arrangement, e.g. due to the location ofthe pipeline coupling along the pipeline.

The actuation mechanism could be operated to cause separation of the shut-off valve housings remotely from a ship or shore-based control room in circumstances where personnel or sensors determine that it is no longer safe or desirable to continue the flow of flowable material along the pipeline. The actuation mechanism could, for example, be operated in circumstances where sensors detect a tensile load applied to the pipeline that exceeds predetermined limits. The tensile load may be applied to the pipeline as a result of unexpected movement of objects or due to excessive pressure within the pipeline.

The actuation mechanism could also be operated to cause separation of the shut-off valve housings when it is desirable to perform maintenance or repair on the pipeline coupling and/or the associated pipeline.

The provision of the or each shut-off valve in the shut-off valve housings that are biased to move to their valve closed positions on separation ofthe shut-off valve housings ensure that the fractured ends of the pipeline are shut-off on operation of the actuation mechanism.

In embodiments employing the use of multiple driving assemblies in the actuation mechanism, the multiple driving assemblies may be formed separately or may be part of the same driving system.

In a preferred embodiment of the invention, the or each first fastening nut may be a hydraulic nut, and the actuation mechanism may include a or a respective hydraulic driving assembly configured to hydraulically drive the or each first fastening nut to disengage the or each first fastening nut from the corresponding first longitudinal fastening member.

The configuration of a hydraulic nut provides an effective means of not only configuring the or each first fastening nut to be in engagement with the corresponding first longitudinal fastening member to reliably secure the shut-off valve housings to each other, but also disengaging the or each first fastening nut from the corresponding first longitudinal fastening member to ensure reliable separation of the shut-off valve housings on demand.

The configuration of the or each hydraulic nut may vary.

For example, the or each hydraulic nut may include outer and inner nut portions, the outer nut portion enclosing the inner nut portion and including an inner face with a cavity formed therein, the outer nut portion configured to be movable between first and second positions to alter the position of the cavity relative to the inner nut portion, wherein the inner face of the outer nut portion is configured to push the inner nut portion inwards to grip the corresponding first longitudinal fastening member when the outer nut portion is in its first position, and the cavity formed in the inner face is positioned to permit outward expansion of the inner nut portion into the cavity when the outer nut portion is in its second position, and wherein the or each hydraulic nut further includes a hydraulic chamber arranged such that a change in hydraulic pressure in the hydraulic chamber causes the outer nut portion to move between its first and second positions.

Alternatively the or each first fastening nut may take the form of a different type of nut (e.g. a pneumatic nut) that can be mechanically driven to disengage the or each first fastening nut from the corresponding first longitudinal fastening member.

The or each first longitudinal fastening member may vary in terms of type and configuration.

The or each first longitudinal fastening member may be a stud, bolt or pin. The or each first longitudinal fastening member may be any one of:

• a threaded longitudinal fastening member;

• a barbed longitudinal fastening member;

• a top hat longitudinal fastening member;

• a longitudinal fastening member with a circumferential shoulder formed thereon;

• a longitudinal fastening member with a circumferential cut-out section formed therein;

• a longitudinal fastening member with a circumferential groove formed thereon;

• a longitudinal fastening member with a circumferential tapered section formed thereon;

• a longitudinal fastening member with a circumferential scalloped section formed thereon.

The or each first longitudinal fastening member may be formed to include a weakened portion that breaks on exposure to a tensile load exceeding a predetermined limit.

The combination of a fastening nut and a longitudinal fastening member with a weakened portion in the or each first fastening arrangement provides the pipeline coupling with different modes of separating the shut-off valve housings from each other. Each mode may be designed to be carried out under respective different conditions.

Forming the or each first longitudinal fastening member to include the weakened portion permits the automatic separation of the shut-off valve housings in response to the tensile load exceeding a predetermined limit, which for example may occur as a result of unexpected movement of objects connected to the ends of the associated pipeline or due to excessive pressure within the pipeline.

Meanwhile the use of the first fastening nut with the first longitudinal fastening member in the or each first fastening arrangement permits controlled separation of the shut-off valve housings from each other without breaking the or each first longitudinal fastening member, which for example may be required during maintenance or repair of the pipeline coupling and/or the associated pipeline. This advantageously obviates the need to replace the or each broken first longitudinal fastening member every time the shut-off valve housings are separated from each other.

The shut-off valve housings may be secured to each other, either directly or indirectly.

In embodiments of the invention, the shut-off valve housings may be directly secured to each other via the or each first fastening arrangement.

The or each first longitudinal fastening member may extend through adjacent portions of the shut-off valve housings when the shut-off valve housings are directly secured to each other via the or each first fastening arrangement. In such embodiments, each adjacent portion may be a flange.

Instead of directly securing the shut-off valve housings to each other, the pipeline coupling may further include a collar arranged between the shut-off valve housings, a first of the shut-off valve housings secured to the collar via the or each first fastening arrangement, the or each first fastening arrangement permitting the collar and first shut-off valve housing to separate from each other on operation of the actuation mechanism operably engaged with the or each first fastening arrangement, a second of the shut-off valve housings secured to the collar via at least one second fastening arrangement, the or each second fastening arrangement permitting the collar and second shut-off valve housing to separate from each other.

The arrangement of the collar in an intermediate position between the shut-off valve housings permits separation of the shut-off valve housings through separation of the collar and first shut-off valve housing, through separation of the collar and second shut-off valve housing, or both. This provides greater flexibility in designing the pipeline coupling to enable separation of the shut-off valve housings across a range of conditions, without adversely impacting on the normal operation of the or each shut-off valve.

The pipeline coupling may be designed so that separation of the collar and first shut-off valve housing takes place under one set of conditions, e.g. when maintenance or repair of the pipeline coupling and/or pipeline is required, while separation of the collar and second shut-off valve housing takes place under another set of conditions, e.g. in response to a tensile load applied to the pipeline exceeding a predetermined limit. In addition, different fastening arrangements can be used for the first and second fastening arrangements, which provides further flexibility in designing the pipeline coupling to enable separation of the shut-off valve housings across a range of conditions.

The or each first longitudinal fastening member may extend through adjacent portions of the collar and first shut-off valve housing when the collar and first shut-off valve housing are secured to each other via the or each first fastening arrangement.

The or each second longitudinal fastening member may vary in terms of type and configuration.

The or each second fastening arrangement may include a second longitudinal fastening member.

In embodiments employing the use of one or more second longitudinal fastening members, the or each second fastening arrangement may further include a second fastening nut, the or each second fastening nut in engagement with the corresponding second longitudinal fastening member to secure the collar and second shut-off valve housing to each other.

The or each second longitudinal fastening member may be a stud, bolt or pin. The or each second longitudinal fastening member may be any one of:

• a threaded longitudinal fastening member;

• a barbed longitudinal fastening member;

• a top hat longitudinal fastening member;

The or each second longitudinal fastening member may be formed to include a weakened portion that breaks on exposure to a tensile load exceeding a predetermined limit.

Forming the or each second longitudinal fastening member to include the weakened portion permits the automatic separation of the shut-off valve housings in response to the tensile load exceeding a predetermined limit, which for example may occur as a result of unexpected movement of objects connected to the ends of the associated pipeline or due to excessive pressure within the pipeline.

Hence, the use of the second longitudinal fastening member with the weakened portion in the or each second fastening arrangement may be designed to permit a responsive separation of the collar and second shut-off valve housing in order to separate the shut-off valve housings from each other, while the or each first fastening arrangement can be designed to permit controlled separation of the collar and first shut-off valve housing in order to separate the shut-off valve housings from each other. This configuration not only maintains the pipeline coupling’s ability to automatically separate the shut-off valve housings in response to the tensile load exceeding a predetermined limit, but also permits separation of the shut-off valve housings while preventing breakage of the or each second longitudinal fastening member, thus obviating the need to replace the or each broken second longitudinal fastening member every time the shut-off valve housings are separated from each other.

The or each second longitudinal fastening member may extend through adjacent portions of the collar and second shut-off valve housing when the collar and second shut-off valve housing are secured to each other via the or each second fastening arrangement

In embodiments employing the use of one or more longitudinal fastening members extending through adjacent portions, each adjacent portion may be a flange.

In further embodiments of the invention, the pipeline coupling may include a respective shut-off valve located within the hollow bore of each shut-off valve housing, each shut-off valve including a valve member movable between a valve open position and a valve closed position in which the valve member shuts off the flow of a flowable material through the hollow bore, each valve member being biased to move to its valve closed position on separation of the shut-off valve housings.

According to a further aspect of the invention, there is provided the use of a pipeline coupling as a breakaway coupling or a release coupling, wherein the pipeline coupling is in accordance with any one of the embodiments of the first aspect of the invention.

It will be appreciated that the use of the terms “first” and “second” and the like in the patent specification is merely intended to help distinguish between similar features (e.g. the first and second shut-off valve housings), and is not intended to indicate the relative importance of one feature over another feature.

Preferred embodiments of the invention will now be described, by way of non-limiting examples, with reference to the accompanying drawings in which:

Figure 1 schematically shows a pipeline coupling according to a first embodiment of the invention;

Figures 2 and 3 schematically show the configuration of a hydraulic nut;

Figures 4 and 5 schematically show the pipeline coupling of Figure 1 in assembled and disassembled configurations;

Figure 6 schematically shows a pipeline coupling according to a second embodiment of the invention

Figures 7 and 8 schematically show the pipeline coupling of Figure 6 in assembled and disassembled configurations;

Figure 9 schematically shows a pipeline coupling according to a third embodiment of the invention;

Figures 10 to 12 schematically show the pipeline coupling of Figure 9 in assembled and disassembled configurations; and

Figure 13 shows examples of longitudinal fastening members.

The figures are not necessarily to scale, and certain features and certain views of the figures may be shown exaggerated in scale or in schematic form in the interests of clarity and conciseness.

A pipeline coupling according to a first embodiment of the invention is shown in Figure 1, and is designated generally by the reference numeral 20. The pipeline coupling 20 is preferably for use as a breakaway coupling (such as a marine breakaway coupling) or a release coupling (such as an emergency release coupling).

The pipeline coupling 20 includes a pair of shut-off valve housings 22, 24 directly secured to each other by means of a plurality of first fastening arrangements. The first fastening arrangements permit the shut-off valve housings 22, 24 to separate from each other on operation of an actuation mechanism operably engaged with each first fastening arrangement.

The shut-off valve housings 22, 24 define a hollow bore along which flowable material may flow.

A respective shut-off valve is located within the hollow bore of each shut-off valve housing 22, 24, and each shut-off valve includes a shut-off valve member 26 movable between a valve open position and a valve closed position. In the valve open position, each shut-off valve member 26 bisects the hollow bore of the respective shut-off valve housing 22, 24. In the valve closed position (not shown) the shut-off valve member 26 sealingly engages against a valve seat defined about the circumference of the respective shut-off valve housing 22, 24 and shuts off the flow of a flowable material through the hollow bore.

Each shut-off valve member 26 is biased to move to its valve closed position on separation of the shut-off valve housings 22, 24. Each shut-off valve member 26 is mounted on a pivot shaft and is biased to move to its valve closed position by means of a spring. The spring preferably includes contra wound spring portions mounted on opposite ends of the pivot shaft and engaged with the shut-off valve members 26 so as to bias each of the shutoff valve members 26 towards the valve closed position.

The shut-off valves are located in the shut-off valve housings 22, 24 in opposed configurations such that, whilst the shut-off valve housings 22, 24 are secured to each other, the opposing shut-off valve members 26 interleave with each other when they are in their valve open positions. This engagement allows each shut-off valve member 26 to oppose movement of the other shut-off valve member 26 until separation of the shut-off valve housings 22, 24 moves the shut-off valve members 26 out of engagement with each other and the bias provided by the springs causes the shut-off valve members 26 to move to their valve closed positions.

An abutment end of each of the shut-off valve housings 22, 24 is formed to define a flange extending about its circumference, the flanges defining opposed contact surfaces which on abutment of the shut-off valve housings 22, 24 are brought into abutting engagement.

Each first fastening arrangement includes a first longitudinal fastening member and a first fastening nut. Each first longitudinal fastening member is in the form of a solid stud 28. Each first fastening nut is in the form of a hydraulic nut 30, which can be hydraulically driven to be disengaged from the corresponding solid stud 28.

Figures 2 and 3 shows the configuration of each hydraulic nut 30.

Each hydraulic nut 30 includes outer and inner nut portions 40, 42 arranged on a base 44 which is arranged adjacent to the flange surface of the first shut-off valve housing 22, with a washer located between the base 44 and the flange surface of the first shut-off valve housing 22. The outer nut portion 40 is in the form of a collar that is arranged to enclose the inner nut portion 42. The inner nut portion 42 includes a threaded insert with an internally threaded wall. A cavity 46 is formed in an inner face of a wall of the outer nut portion 40. The outer nut portion 40 is movable along the axis of the corresponding hydraulic nut 30 between first and second positions to alter the position of the cavity 46 relative to the internally threaded wall of the threaded insert.

When the outer nut portion 40 is in its first position (shown as the “down” position in Figure 2), the inner face of the wail of the outer nut portion 40 abuts the threaded insert so as to push the internally threaded wall of the threaded insert inwards. When the outer nut portion is in its second position (shown as the “up” position in Figure 3), the inner face of the wall of the outer nut portion 40 no longer abuts the threaded insert, but instead the cavity 46 formed in the inner face is now positioned such that the internally threaded wall of the threaded insert is permitted to expand outwards into the cavity 46.

Each hydraulic nut 30 further includes a hydraulic chamber 48 formed between the outer and inner nut portions 40, 42. The hydraulic chamber 48 is arranged such that the outer nut portion 40 is in its first position when there is little to no hydraulic fluid in the hydraulic chamber 48. The hydraulic chamber 48 is further arranged so that the introduction 50 of hydraulic fluid into the hydraulic chamber 48 results in an increase in hydraulic pressure that results in the application of an axial force on the outer nut portion 40, which in turn moves the outer collar from its first position to its second position.

In the embodiment shown in Figure 1, the pipeline coupling 20 includes an actuation mechanism having a plurality of hydraulic driving assemblies, each of which includes a volume of hydraulic fluid (e.g. oil) under pressure (not shown) and arranged to selectively flow into the hydraulic chamber 48 of a respective hydraulic nut 30 in order to hydraulically drive each hydraulic nut 30.

To maintain the abutment surfaces in abutting engagement and thereby directly secure the shut-off valve housings 22, 24 to each other, each hydraulic nut 30 is configured to be in engagement with the corresponding solid stud 28.

Each solid stud 28 is arranged to extend through respective apertures formed about the circumferences of the flanges when their abutment surfaces are in abutting engagement, with a portion of each solid stud 28 protruding above the flange surface of a first of the shut-off valve housings 22, 24. Each hydraulic nut 30 engages the protruding portion of the corresponding solid stud 28 so as to secure the shut-off valve housings 22, 24 together. More specifically, the inner nut portion 42 of each hydraulic nut 30 is arranged to enclose the protruding portion of a respective solid stud 28, and the outer nut portion 40 is moved to its first position in order to push the internally threaded wall of the threaded insert inwards to directly grip the corresponding solid stud 28. This enables each hydraulic nut 30 to effectively form a solid, mechanical nut which can be fitted and torqued in the same manner as a conventional nut

Figure 4 schematically shows the pipeline coupling 20 of Figure 1 when the shut-off valve housings 22, 24 are directly secured to each other.

In this manner the shut-off valve housings 22, 24 are directly secured to each other via each first fastening arrangement.

To separate the shut-off valve housings 22, 24 from each other, each hydraulic nut 30 is configured to disengage from the corresponding solid stud 28.

The actuation mechanism is operated to introduce hydraulic fluid into the hydraulic chamber 48 of each hydraulic nut 30 in order to increase the hydraulic pressure within the hydraulic chamber 48. The increase in hydraulic pressure forces the outer nut portion 40 to move to its second position so as to permit the profile of the corresponding solid stud 28 to push the internally threaded wall of the threaded insert outwards into the corresponding cavity 46. This in turn releases each solid stud 28 from the corresponding threaded insert and thereby permits the disengagement of each hydraulic nut 30 from the corresponding solid stud 28, which allows the second shut-off valve housing 24 to separate from the first shut-off valve housing 22 in order to trigger the movement of the shut-off valve members 26 to their valve closed positions to shut-off the respective hollow bores of the shut-off valve housings 22, 24.

Such operation of the actuation mechanism to disengage each hydraulic nut 30 from the corresponding solid stud 28 may be triggered either by manual operation of the actuation mechanism or by an automatic monitoring system.

Figure 5 schematically shows the pipeline coupling 20 of Figure 1 when the shut-off valve housings 22, 24 are separated from each other.

In this manner the first fastening arrangements permit the controlled separation of the shutoff valve housings 22, 24 from each other.

Examples of each hydraulic nut 30 are described in GB 2373554 A and GB 2421774 A.

It is envisaged that, in other embodiments ofthe invention, each hydraulic nut 30 may be replaced by a different type of hydraulic nut. It is further envisaged that, in still other embodiments of the invention, each hydraulic nut 30 may be replaced by a different type of nut that can be mechanically driven to disengage the nut from the corresponding solid stud 28.

The provision of the first fastening nut and the first longitudinal fastening member in each first fastening arrangement therefore results in a reliable means of securing the shut-off valve housings 22, 24 to each other and separating the shut-off valve housings 22,24 from each other.

The provision of an actuation mechanism that is operable to disengage each first fastening nut from the corresponding first longitudinal fastening member and thereby allow the shutoff valve housings 22, 24 to separate from each other allows selective operation of the pipeline coupling 20 in circumstances where it is desirable to break a pipeline.

It is envisaged that the actuation mechanism could be operated to cause separation of the shut-off valve housings 22, 24 remotely from a ship or shore-based control room. The actuation mechanism could, for example, be operated to cause separation when personnel and/or sensors determine that it is no longer safe or desirable to continue the flow of flowable material along the pipeline.

Whilst such circumstances would very likely arise when sensors detect a tensile load applied to the pipeline that exceeds a predetermined limit, as is the case with conventional pipeline couplings, it is envisaged that remote operation of the actuation mechanism could also allow the pipeline coupling 20 to be broken in response to other non-tensile load related safety concerns and the usefulness of the pipeline coupling 20 is not therefore limited solely to addressing problems associated with tensile loads in the pipeline.

In addition the provision of the actuation mechanism to aid in the separation of the shutoff valve housings 22, 24 is particularly beneficial when it is difficult to access each first fastening arrangement, e.g. due to the location of the pipeline coupling 20 along the pipeline.

A pipeline coupling according to a second embodiment of the invention is shown in Figure 6, and is designated generally by the reference numeral 120. The pipeline coupling 120 of Figure 6 is similar in structure and operation to the pipeline coupling 20 of Figure 1, and like features share the same reference numerals.

The pipeline coupling 120 of Figure 6 differs from the pipeline coupling 20 of Figure 1 in that, in the pipeline coupling 120 of Figure 6, each solid stud 28 is replaced by a respective breakstud 32, which is formed to include a weakened portion that breaks on exposure to a tensile load exceeding a predetermined limit. Such a tensile load may be applied to the pipeline as a result of unexpected movement of objects connected to the ends of the associated pipeline or due to excessive pressure within the pipeline.

The use of a respective breakstud 32 with the weakened portion in place of each solid stud 28 permits the automatic separation of the shut-off valve housings 22, 24 in response to the tensile load exceeding a predetermined limit. More particularly, upon application of such a tensile load, each breakstud 32 breaks at its weakest section, thus permitting the second shut-off valve housing 24 to separate from the first shut-off valve housing 22 in order to trigger the movement of the shut-off valve members 26 to their valve closed positions to shut-off the respective hollow bores of the shut-off valve housings 22, 24. Such automatic separation is carried out independently of any control and/or monitoring system.

The hydraulic nut 30 and breakstud 32 combination of the pipeline coupling 120 of Figure 6 enables the first fastening arrangements to directly secure the shut-off valve housings 22, 24 to each other and to permit the controlled separation of the shut-off valve housings 22, 24 from each other, in the same way as the hydraulic nut 30 and solid stud 28 combination of the pipeline coupling 20 of Figure 1.

Furthermore the use of the hydraulic nut 30 with the breakstud 32 in each first fastening arrangement permits controlled separation of the shut-off valve housings 22, 24 from each other without breaking each breakstud 32. This advantageously obviates the need to replace the broken breakstuds 32 every time the shut-off valve housings 22, 24 are separated from each other.

Figure 7 schematically shows the pipeline coupling 120 of Figure 6 when the shut-off valve housings 22, 24 are directly secured to each other, while Figure 8 schematically shows the pipeline coupling 120 of Figure 6 when the shut-off valve housings 22,24 are separated from each other.

As a result the pipeline coupling 120 of Figure 6 has passive and active modes of separating the shut-off valve housings 22, 24 from each other.

A pipeline coupling according to a third embodiment of the invention is shown in Figure 9, and is designated generally by the reference numeral 220. The pipeline coupling 220 of Figure 9 is similar in structure and operation to the pipeline coupling 20 of Figure 1, and like features share the same reference numerals.

The pipeline coupling 220 of Figure 9 differs from the pipeline coupling 20 of Figure 1 in that the pipeline coupling 220 of Figure 9 further includes a collar 34 arranged between the shut-off valve housings 22, 24. In particular, the collar 34 is in abutting engagement between the shut-off valve housings 22, 24.

The flanges of the shut-off valve housings 22, 24 are spaced apart to accommodate the intermediate collar 34. On abutment of the shut-off valve housings 22, 24 with the collar 34, the contact surfaces of the flanges of the shut-off valve housings 22, 24 are respectively brought into abutting engagement with contact surfaces on opposite sides of the collar 34.

The pipeline coupling 220 of Figure 9 includes a plurality of first fastening arrangements and a plurality of second fastening arrangements. The shut-off valve housings 22, 24 are indirectly secured to each other via the intermediate collar 34 and the first and second fastening arrangements.

The first fastening arrangements permit the shut-off valve housings 22, 24 to separate from each other on operation of an actuation mechanism operably engaged with each first fastening arrangement.

In the embodiment shown in Figure 9, the pipeline coupling 220 includes an actuation mechanism having a plurality of hydraulic driving assemblies, each of which includes a volume of hydraulic fluid (e.g. oil) under pressure (not shown) and arranged to selectively flow into the hydraulic chamber 48 of a respective hydraulic nut 30 in order to hydraulically drive each hydraulic nut 30.

To maintain the abutment surfaces of the collar 34 and first shut-off valve housing 22 in abutting engagement and thereby secure the collar 34 and first shut-off valve housing 22 to each other, each hydraulic nut 30 is configured to be in engagement with the corresponding solid stud 28.

Figure 10 schematically shows the pipeline coupling 220 of Figure 9 when the shut-off valve housings 22, 24 are secured to each other via the collar 34.

Each solid stud 28 is arranged to extend through respective apertures formed about the circumferences of the collar 34 and the flange of the first shut-off valve housing 22 when their abutment surfaces are in abutting engagement, with a portion of each solid stud 28 protruding above the flange surface of the first shut-off valve housing 22. Each hydraulic nut 30 engages the protruding portion of the corresponding solid stud 28 so as to secure the collar 34 and first shut-off valve housing 22 together. More specifically, the inner nut portion 42 of each hydraulic nut 30 is arranged to enclose the protruding portion of a respective solid stud 28, and the outer nut portion 40 is moved to its first position in order to push the internally threaded wall of the threaded insert inwards to directly grip the corresponding solid stud 28. This enables each hydraulic nut 30 to effectively form a solid, mechanical nut which can be fitted and torqued in the same manner as a conventional nut.

In this manner the collar 34 and first shut-off valve housing 22 are secured to each other via each first fastening arrangement.

To separate the collar 34 and first shut-off valve housing 22 from each other, each hydraulic nut 30 is configured to disengage from the corresponding solid stud 28.

The actuation mechanism is operated to introduce hydraulic fluid into the hydraulic chamber 48 of each hydraulic nut 30 in order to increase the hydraulic pressure within the hydraulic chamber 48. The increase in hydraulic pressure forces the outer nut portion 40 to move to its second position so as to permit the profile of the corresponding solid stud 28 to push the internally threaded wall of the threaded insert outwards into the corresponding cavity 46 This in turn releases each solid stud 28 from the corresponding threaded insert and thereby permits the disengagement of each hydraulic nut 30 from the corresponding solid stud 28, which allows the first shut-off valve housing 22 to separate from the collar 34. This in turn allows the shut-off valve housings 22, 24 to separate from each other in order to trigger the movement of the shut-off valve members 26 to move to their valve closed positions to shut-off the respective hollow bores of the shut-off valve housings 22, 24.

Figure 11 schematically shows the pipeline coupling 220 of Figure 9 when the collar 34 and first shut-off valve housing 22 are separated from each other.

In this manner the first fastening arrangements permit the controlled separation of the collar 34 and first shut-off valve housing 22 from each other. This allows selective operation of the pipeline coupling 220 in circumstances where it is desirable to break a pipeline. Examples of such circumstances are outlined above with reference to the pipeline coupling 20 of Figure 1.

Each second fastening arrangement includes a second longitudinal fastening member and a second fastening nut. Each second longitudinal fastening member is in the form of a breakstud 32. Each second fastening nut 36 is in the form of a conventional nut.

To maintain the abutment surfaces of the collar 34 and second shut-off valve housing 24 in abutting engagement and thereby secure the collar 34 and second shut-off valve housing 24 to each other, each second fastening nut 36 is configured to be in engagement with the corresponding breakstud 32.

Each breakstud 32 is arranged to extend through respective apertures formed about the circumferences of the collar 34 and the flange of the second shut-off valve housing 24 when their abutment surfaces are in abutting engagement, with a portion of each breakstud 32 protruding above the flange surface of the second shut-off valve housing 24. Each second fastening nut 36 engages the protruding portion of the corresponding breakstud 32 such that each second fastening nut 36 is arranged adjacent to the flange surface of the second shut-off valve housing 24, with a washer located between the second fastening nut 36 and the flange surface of the second shut-off valve housing 24.

In this manner the collar 34 and second shut-off valve housing 24 are secured to each other via each second fastening arrangement.

Each breakstud 32 is formed to include a weakened portion that breaks on exposure to a tensile load exceeding a predetermined limit. Such a tensile load may be applied to the pipeline as a result of unexpected movement of objects connected to the ends of the associated pipeline or due to excessive pressure within the pipeline.

The use of a respective breakstud 32 with the weakened portion in each second fastening arrangement permits the automatic separation of the collar 34 and the second shut-off valve housing 24 in response to the tensile load exceeding a predetermined limit. More particularly, upon application of such a tensile load, each breakstud 32 breaks at its weakest section, thus permitting the second shut-off valve housing 24 to separate from the collar 34. This in turn allows the shut-off valve housings 22, 24 to separate from each other in order to trigger the movement of the shut-off valve members 26 to their valve closed positions to shut-off the respective hollow bores of the shut-off valve housings 22, 24. Such automatic separation is carried out independently of any control and/or monitoring system.

Figure 12 schematically shows the pipeline coupling 220 of Figure 9 when the collar 34 and second shut-off valve housing 24 are separated from each other.

In this manner the second fastening arrangements permit the automatic separation of the collar 34 and second shut-off valve housing 24 from each other.

Hence, the use of the breakstud 32 with the weakened portion in each second fastening arrangement permits a responsive separation of the collar 34 and second shut-off valve housing 24 in order to separate the shut-off valve housings 22, 24 from each other, while the use of the hydraulic nut 30 and solid stud 28 in each first fastening arrangement permits controlled separation of the collar 34 and first shut-off valve housing 22 in order to separate the shut-off valve housings 22, 24 from each other. The latter prevents breakage of the breakstuds 32 when the collar 34 and first shut-off valve housing 22 are separated from each other, thus obviating the need to replace the broken breakstuds 32 every time the shut-off valve housings 22, 24 are separated from each other.

As a result the pipeline coupling 220 of Figure 9 has passive and active modes of separating the shut-off valve housings 22, 24 from each other. This has the effect of improving the reliability of the pipeline coupling 220 when carrying out the separation of the shut-off valve housings 22, 24 from each other.

This configuration of the pipeline coupling 220 of Figure 9 also advantageously provides greater flexibility in designing the pipeline coupling 220 to enable separation of the shutoff valve housings 22, 24 across a range of conditions, without adversely impacting on the normal operation of the shut-off valves. The pipeline coupling 220 may be designed so that separation of the collar 34 and first shut-off valve housing 22 takes place under one set of conditions, e.g. when maintenance or repair of the pipeline is required, while separation of the collar 34 and second shut-off valve housing 24 takes place in response to a tensile load on the pipeline exceeding a predetermined limit. Furthermore, as described above, different fastening arrangements can be used for the first and second fastening arrangements, which provides further flexibility in designing the pipeline coupling 220 to enable separation of the shut-off valve housings 22, 24 across a range of conditions.

In the embodiments of Figures 1 to 3, the shut-off valve arrangement is commonly known as a flip-flap valve arrangement, examples of which are described in EP 2 000 730 A2. It is envisaged that, in other embodiments of the invention, the shut-off valve arrangement may be replaced by other shut-off valve arrangements, including a petal valve arrangement (such as described in EP 0 006 278 A1 and GB 2051993 A) and a sleevebased valve arrangement (such as described in GB 2391051 A).

In embodiments of the invention, one of the first and second shut-off valve housings 22, 24 may be the upstream shut-off valve housing, and the other of the first and second shutoff valve housings 22, 24 may be the downstream shut-off valve housing.

In other embodiments of the invention, it is envisaged that each longitudinal fastening member 28,32 may be in the form of a bolt or pin instead of a stud, and/or each longitudinal fastening member 28, 32 may be threaded or unthreaded. Each longitudinal fastening member 28, 32 may instead be any one of: a barbed longitudinal fastening member 52; a top hat longitudinal fastening member 54; a longitudinal fastening member with a circumferential shoulder formed thereon 56; a longitudinal fastening member with a circumferential cut-out section formed therein 58; a longitudinal fastening member with a circumferential groove formed thereon 60; a longitudinal fastening member with a circumferential tapered section formed thereon 62; ora longitudinal fastening member with a circumferential scalloped section formed thereon 64, as shown in Figure 13.

In still other embodiments of the invention, it is envisaged that the pipeline coupling may include only one of the shut-off valves, with the single shut-off valve being located in one of the shut-off valve housings 22, 24. In such embodiments, a separate mechanism may be used to oppose the movement of the shut-off valve member 26 of the single shut-off valve in order to maintain the shut-off valve member 26 in its valve open position when the shut-off valve housings 22,24 are secured to each other.

Claims

1. A pipeline coupling comprising:

a pair of shut-off valve housings secured to each other via at least one first fastening arrangement, the shut-off valve housings defining a hollow bore along which flowable material may flow, the or each first fastening arrangement permitting the shut-off valve housings to separate from each other on operation of an actuation mechanism operably engaged with the or each first fastening arrangement; and at least one shut-off valve located within the hollow bore of at least one of the shutoff valve housings, the or each shut-off valve including a valve member movable between a valve open position and a valve closed position in which the valve member shuts off the flow of a flowable material through the hollow bore, the or each valve member being biased to move to its valve closed position on separation of the shut-off valve housings, wherein the or each first fastening arrangement includes a first longitudinal fastening member and a first fastening nut, the or each first fastening nut in engagement with the corresponding first longitudinal fastening member to secure the shut-off valve housings to each other, and the actuation mechanism includes a or a respective driving assembly configured to mechanically drive the or each first fastening nut to disengage the or each first fastening nut from the corresponding first longitudinal fastening member.

2. A pipeline coupling according to Claim 1 wherein the or each first fastening nut is a hydraulic nut, and the actuation mechanism includes a or a respective hydraulic driving assembly configured to hydraulically drive the or each first fastening nut to disengage the or each first fastening nut from the corresponding first longitudinal fastening member.

3. A pipeline coupling according to Claim 2 wherein the or each hydraulic nut includes outer and inner nut portions, the outer nut portion enclosing the inner nut portion and including an inner face with a cavity formed therein, the outer nut portion configured to be movable between first and second positions to alter the position of the cavity relative to the inner nut portion, wherein the inner face of the outer nut portion is configured to push the inner nut portion inwards to grip the corresponding first longitudinal fastening member when the outer nut portion is in its first position, and the cavity formed in the inner face is positioned to permit outward expansion of the inner nut portion into the cavity when the outer nut portion is in its second position, and wherein the or each hydraulic nut further includes a hydraulic chamber arranged such that a change in hydraulic pressure in the hydraulic chamber causes the outer nut portion to move between its first and second positions.

4. A pipeline coupling according to any one of the preceding claims wherein the or each first longitudinal fastening member is a stud, bolt or pin.

5. A pipeline coupling according to any one of the preceding claims wherein the or each first longitudinal fastening member is any one of:

• a threaded longitudinal fastening member;

• a barbed longitudinal fastening member;

• a top hat longitudinal fastening member;

• a longitudinal fastening member with a circumferential tapered section formed therein;

• a longitudinal fastening member with a circumferential scalloped section formed therein.

6. A pipeline coupling according to any one of the preceding claims wherein the or each first longitudinal fastening member is formed to include a weakened portion that breaks on exposure to a tensile load exceeding a predetermined limit.

7. A pipeline coupling according to any one of the preceding claims wherein the shutoff valve housings are directly secured to each other via the or each first fastening arrangement.

8. A pipeline coupling according to Claim 7 wherein the or each first longitudinal fastening member extends through adjacent portions of the shut-off valve housings when the shut-off valve housings are directly secured to each other via the or each first fastening arrangement.

9. A pipeline coupling according to Claim 8 wherein each adjacent portion is a flange.

10. A pipeline coupling according to any one of Claims 1 to 6 further including a collar arranged between the shut-off valve housings, a first of the shut-off valve housings secured to the collar via the or each first fastening arrangement, the or each first fastening arrangement permitting the collar and first shut-off valve housing to separate from each other on operation of the actuation mechanism operably engaged with the or each first fastening arrangement, a second of the shut-off valve housings secured to the collar via at least one second fastening arrangement, the or each second fastening arrangement permitting the collar and second shut-off valve housing to separate from each other.

11. A pipeline coupling according to Claim 10 wherein the or each first longitudinal fastening member extends through adjacent portions of the collar and first shut-off valve housing when the collar and first shut-off valve housing are secured to each other via the or each first fastening arrangement.

12. A pipeline coupling according to Claim 10 or Claim 11 wherein the or each second fastening arrangement includes a second longitudinal fastening member.

13. A pipeline coupling according to Claim 12 wherein the or each second fastening arrangement further includes a second fastening nut, the or each second fastening nut in engagement with the corresponding second longitudinal fastening member to secure the collar and second shut-off valve housing to each other.

14. A pipeline coupling according to Claim 12 or Claim 13 wherein the or each second longitudinal fastening member is a stud, bolt or pin.

15. A pipeline coupling according to any one of Claims 12 to 14 wherein the or each second longitudinal fastening member is any one of:

• a threaded longitudinal fastening member;

• a barbed longitudinal fastening member;

• a top hat longitudinal fastening member;

16. A pipeline coupling according to any one of Claims 12 to 15 wherein the or each second longitudinal fastening member is formed to include a weakened portion that breaks on exposure to a tensile load exceeding a predetermined limit.

5

17. A pipeline coupling according to any one of Claims 12 to 16 wherein the or each second longitudinal fastening member extends through adjacent portions of the collar and second shut-off valve housing when the collar and second shut-off valve housing are secured to each other via the or each second fastening arrangement.

10

18. A pipeline coupling according to Claim 11 or Claim 17 wherein each adjacent portion is a flange.

19. A pipeline coupling according to any one of the preceding claims including a respective shut-off valve located within the hollow bore of each shut-off valve housing,

15 each shut-off valve including a valve member movable between a valve open position and a valve closed position in which the valve member shuts off the flow of a flowable material through the hollow bore, each valve member being biased to move to its valve closed position on separation of the shut-off valve housings.

20

20. Use of a pipeline coupling as a breakaway coupling or a release coupling, wherein the pipeline coupling is in accordance with any one of the preceding claims.

05 12 17

Intellectual

Property

Office

Application No: Claims searched:

20 20. Use of a pipeline coupling as a breakaway coupling or a release coupling, wherein the pipeline coupling is in accordance with any one of the preceding claims.

21. A pipeline coupling substantially as herein described with reference to and/or as illustrated in the accompanying figures.

22. Use of a pipeline coupling as a breakaway coupling or a release coupling substantially as herein described with reference to and/or as illustrated in the accompanying figures.

Amendments to the claims have been made as follows:

1. A pipeline coupling comprising:

a pair of shut-off valve housings secured to each other via at least one first 5 fastening arrangement, the shut-off valve housings defining a hollow bore along which flowable material may flow, the or each first fastening arrangement permitting the shut-off valve housings to separate from each other on operation of an actuation mechanism operably engaged with the or each first fastening arrangement; and at least one shut-off valve located within the hollow bore of at least one of the shut10 off valve housings, the or each shut-off valve including a valve member movable between a valve open position and a valve closed position in which the valve member shuts off the flow of a flowable material through the hollow bore, the or each valve member being biased to move to its valve closed position on separation of the shut-off valve housings, wherein the or each first fastening arrangement includes a first longitudinal

15 fastening member and a first fastening nut, the or each first fastening nut in engagement with the corresponding first longitudinal fastening member to secure the shut-off valve housings to each other, and the actuation mechanism includes a, or a respective, driving assembly configured to mechanically drive the or each first fastening nut to disengage the

CM or each first fastening nut from the corresponding first longitudinal fastening member.

Ί- 20

LO 2. A pipeline coupling according to Claim 1 wherein the or each first fastening nut is a hydraulic nut, and the actuation mechanism includes a, or a respective, hydraulic driving assembly configured to hydraulically drive the or each first fastening nut to disengage the or each first fastening nut from the corresponding first longitudinal fastening member.

3. A pipeline coupling according to Claim 2 wherein the or each hydraulic nut includes outer and inner nut portions, the outer nut portion enclosing the inner nut portion and including an inner face with a cavity formed therein, the outer nut portion configured to be movable between first and second positions to alter the position of the cavity relative to

30 the inner nut portion, wherein the inner face of the outer nut portion is configured to push the inner nut portion inwards to grip the corresponding first longitudinal fastening member when the outer nut portion is in its first position, and the cavity formed in the inner face is positioned to permit outward expansion of the inner nut portion into the cavity when the outer nut

35 portion is in its second position, and wherein the or each hydraulic nut further includes a hydraulic chamber arranged such that a change in hydraulic pressure in the hydraulic chamber causes the outer nut portion to move between its first and second positions.

5 4. A pipeline coupling according to any one of the preceding claims wherein the or each first longitudinal fastening member is a stud, bolt or pin.

10 · a threaded longitudinal fastening member;

• a barbed longitudinal fastening member;

• a top hat longitudinal fastening member;

• a longitudinal fastening member with a circumferential cut-out section formed

15 therein;

• a longitudinal fastening member with a circumferential scalloped section formed

20 therein.

30 8. A pipeline coupling according to Claim 7 wherein the or each first longitudinal fastening member extends through adjacent portions of the shut-off valve housings when the shut-off valve housings are directly secured to each other via the or each first fastening arrangement.

35 9. A pipeline coupling according to Claim 8 wherein each adjacent portion is a flange.

10. A pipeline coupling according to any one of Claims 1 to 6 further including a collar arranged between the shut-off valve housings, a first of the shut-off valve housings secured to the collar via the or each first fastening arrangement, the or each first fastening arrangement permitting the collar and first shut-off valve housing to separate from each other on operation of the actuation mechanism operably engaged with the or each first fastening arrangement, a second of the shut-off valve housings secured to the collar via at least one second fastening arrangement, the or each second fastening arrangement

5 permitting the collar and second shut-off valve housing to separate from each other.

11. A pipeline coupling according to Claim 10 wherein the or each first longitudinal fastening member extends through adjacent portions of the collar and first shut-off valve housing when the collar and first shut-off valve housing are secured to each other via the

1 o or each first fastening arrangement.

15 13. A pipeline coupling according to Claim 12 wherein the or each second fastening arrangement further includes a second fastening nut, the or each second fastening nut in engagement with the corresponding second longitudinal fastening member to secure the collar and second shut-off valve housing to each other.

20 14. A pipeline coupling according to Claim 12 or Claim 13 wherein the or each second longitudinal fastening member is a stud, bolt or pin.

25 · a threaded longitudinal fastening member;

• a barbed longitudinal fastening member;

• a top hat longitudinal fastening member;

30 therein;

35 thereon.

5 17. A pipeline coupling according to any one of Claims 12 to 16 wherein the or each second longitudinal fastening member extends through adjacent portions of the collar and second shut-off valve housing when the collar and second shut-off valve housing are secured to each other via the or each second fastening arrangement.

10 18. A pipeline coupling according to Claim 11 or Claim 17 wherein each adjacent portion is a flange.