WO2013070077A1

WO2013070077A1 - Method and device for coupling floating pipe sections

Info

Publication number: WO2013070077A1
Application number: PCT/NL2012/050791
Authority: WO
Inventors: Cornelis Albert Van Der Neut; Erwin Cornelis Johannes Bijvoet; Timothy Alexander Van Opstal
Original assignee: Ihc Holland Ie B.V.
Priority date: 2011-11-08
Filing date: 2012-11-08
Publication date: 2013-05-16
Also published as: NL2007751C2; EP2776749A1

Abstract

A pipe connection device (30) for attaching a first end part (3) of a first floating pipe section (2) to a second end part (3) of a second floating pipe section (2) to form a floating pipeline (1), includes a first pipe positioning member (31) arranged to receive and hold the first end part (3) and a second pipe positioning member (32) arranged to receive and hold the second end part (3). The first and second pipe positioning members (31, 32) are moveably mounted and arranged to perform a relative movement towards each other from a first holding position for positioning the end parts of the pipe sections, towards a second coupling position for connecting the end parts of the pipe sections to each other to form a pipeline. The pipe connection device may be mounted to a vessel.

Description

Method and device for coupling floating pipe sections

TECHNICAL FIELD

The invention relates to a vessel comprising a device for attaching a first end part of a first floating pipe section to a second end part of a second floating pipe section to form a floating pipe system.

The invention also relates to a device for attaching a first end part of a first floating pipe section to a second end part of a second floating pipe section to form a floating pipe system.

Furthermore, the invention relates to a floating pipe section and a pipe connection system for the coupling of such pipe sections.

In addition, the invention relates to a method for coupling floating pipe sections.

BACKGROUND

Floating pipe systems are known and are used to transport material, such as dredging materials, from a first to a second location over a water surface.

Floating pipe systems may be formed by a number of floating pipe segments which are connected to each other. The different floating pipe segments may for instance be rigid pipe segments which are mutually connected. The floating pipe segments may comprise buoyant members and may also be carried on floats or pontoons. The attached floating pipe segments can form a floating pipe system.

Other non-floating pipe systems are also known which may be constructed from individual pipe segments. WO2011/072327 discloses a device for attaching subsea sections to each other to form a pipe system, the device comprising a first jaw and a second jaw for engaging the pipe sections together.

Although in theory, use of such coupling arrangements may seem

straightforward, in practice it is relatively difficult to connect floating pipe sections especially in off-shore conditions, as mutual positioning of the floating pipe sections is disturbed by wind and waves. Furthermore, in cases where a seal or packing is provided between the pipe ends, any relative transverse movement between the pipe ends during the coupling operation may cause damage to the seal. It would therefore be desirable to provide an alternative pipe coupling system that facilitates connection of floating pipe sections even in windy and wavy

circumstances. BRIEF DESCRIPTION OF THE INVENTION

According to a first aspect of the invention, there is provided a pipe connection system for the coupling of floating pipe sections to form a floating pipeline, comprising a plurality of pipe sections, each pipe section having a connection flange at each of its extremities and a guiding element adjacent to and spaced from the connection flange; a pipe connection device comprising first and second jaws acting as pipe positioning members, moveably mounted relative to each other, each jaw having guides, shaped to interact with the guiding elements to guide a respective pipe end from a receiving region of the jaws to a holding region of the jaws; and an actuator device arranged to move the jaws relative to each other to bring together in alignment, the connection flanges of two pipe sections held in the holding region of the jaws.

In a preferred form of the invention, the guides have a funnel-like configuration to lead the guiding elements from a relatively open guide at the receiving region to a relatively narrow guide in the holding region. In this way, the pipe elements may be drawn into the jaws using a tether system, even in relatively rough conditions.

The system preferably also comprises a plurality of coupling collars, each sized to engage a pair of connection flanges of two pipe sections placed in alignment within the jaws. In this manner, a bolt free connection can be easily achieved whereby the coupling collar may be applied to the connection flanges while the guiding elements are being held in position in the holding region of the jaws. The coupling collars are sized to pass around the connection flanges between the jaws even when the jaws are moved to bring the connection flanges together. This is due to the fact that the guiding elements are sufficiently spaced from the connection flanges so that the jaws do not interfere with the coupling collars.

Furthermore, the invention relates to a floating pipe section for dredging or the like, having a first and a second end part, wherein at least one end part is provided with a connection flange at its extremity and a guiding element adjacent to and spaced from the connection flange. In the present context, a floating pipe section is understood to be a pipe that is capable of floating on water even when the interior of the pipe section is open for water to flow through. Such pipes may include buoyant members but also may include pipes combined with separate floats or carried on pontoons. Such pipes may have a length of at least 5 metres and a bore of at least 30 cm. An outer diameter of the pipe may be from 60 cm to 1 m or even more. The pipe may have a steel inner surrounded by a buoyant outer sleeve. Alternatively rubber and steel composite structures may be used. For dredging purposes, wear due to abrasion can be extreme, and it is often preferable to use relatively cheap structures that will wear out and can be replaced rather than attempt to achieve longevity at greater cost.

In a preferred form of the invention, the guiding element also comprises a circumferential flange. This guide flange may be distanced from the connection flange by at least 5 cm preferably by around 10 cm or more but generally less than 50 cm. The guiding flange is preferably of greater diameter than the connection flange. The guiding flange may also be smaller in diameter than the outer diameter of the pipe section. Although in general the end part may be integral with the floating pipe section it is also envisaged that it may be an additional element retrofitted to the connection flange of an existing floating pipe section by welding or bolting or the like. Each pipe section may be provided with two such end parts which may be identical or different. In particular, one end part may carry the coupling element, which may be pivotally retained on the end section by a retaining ring or the like.

The invention also relates to a device for attaching a first end part of a first floating pipe section to a second end part of a second floating pipe section to form a floating pipeline, wherein the device comprises a first pipe positioning member arranged to receive and hold the first end part, a second pipe positioning member arranged to receive and hold the second end part, wherein the first and second pipe positioning members are arranged to perform a relative movement towards each other from a first holding position for positioning the end parts of the pipe sections, towards a second coupling position for connecting the end parts of the pipe sections to each other.

In the first position, the pipe sections are accommodated in the pipe positioning members and may be accurately held in this position. When moving from the first to the second position, the pipe sections remain positioned in the pipe positioning members, such that they are aligned when in the second position. In the second position, the first and second end parts abut and can then be coupled together. By accurately holding the respective pipe ends in this manner and subsequently bringing them together, relative movement of the pipe ends in a lateral direction may be substantially eliminated. It will be understood that in this manner, a pipeline may be built up by adding additional pipe sections to an existing pipeline or by replacing worn or damaged pipe sections from an existing pipeline. Alternatively, two floating pipelines having appropriate end parts may be joined together. Even in the case of offshore operation, accurate coupling of the pipes may thus be achieved without risk of damaging a seal due to lateral movement.

The movement from the first to the second position may be axial and aligned with the first and second pipe sections. Alternatively and according to one aspect of the invention, the first and second pipe positioning members move from a first position wherein the axial directions of the first and second positioning members are at a mutual angle a greater than 0°, towards a second position wherein the axial directions of the first and second pipe positioning members are mutually parallel and aligned.

As the axial directions are not parallel in the first position, it is made easier to manoeuvre the end parts of the floating pipe sections into the receiving members, for instance by hoisting the end parts above the water surface. The movement from the first to the second position is such that the floating pipe sections are aligned and moved towards each other to allow attaching the floating pipe sections to each other. The value of a will depend on the actual configuration of the pipe system and the flexibility of the pipes being used. The skilled person will be aware of how to choose this value according to the movement required and in particular according to the amount of space required between the pipe ends while introducing them into the pipe positioning members. In general, for systems requiring seals to be mounted between the first and second end parts, a greater spacing will be required and the angle a may be greater.

According to an aspect of the invention, the first and second pipe positioning members may each have a longitudinal axis perpendicular to their axial direction, and the longitudinal axes may define a V-shape in the first position with a mutual angle a greater than 0° and the relative movement comprises a relative rotation of the first and second pipe positioning members through the angle a. In this configuration, the longitudinal axes may intersect and hinge about a generally horizontal axis or pivot point. In a still further embodiment, the device may also comprises a transverse guide for guiding the first and second pipe positioning members for movement in a direction generally perpendicular to an axis of the pipeline. This transverse guide may preferably be a vertical guide for lifting and lowering the first and second pipe positioning members with respect to the water. Such a vertical transverse guide may be used to lower a joint while pivoting the first and second pipe positioning members towards each other. In that case, the hinge axis may be connected to move along the transverse guide.

As an alternative to a horizontal pivot, the first and second pipe positioning members may also be arranged to move about a vertically oriented axis. In this manner end parts of pipe sections may be connected by pivoting together while remaining on the plane defined by the water surface.

According to a further aspect of the invention, a gap may be provided between the first and second pipe positioning members when in the second position. The gap allows a connection member to pass between the pipe positioning members for joining connecting flanges provided at each extremity of each first and second pipe sections while being held in a parallel and aligned position by the first and second pipe receiving members.

According to an important aspect of a preferred embodiment of the invention, each pipe positioning member is provided with a guide for guiding a guiding element provided adjacent to and spaced from the connection flange, from a receiving region of the pipe positioning member to a holding region of the pipe positioning member. By providing such a guide which collaborates with a guide element on the pipe end, the pipe sections are easily received and positioned at a defined position within the pipe positioning members. The skilled person will be aware of various manners in which such guides may be achieved according to the chosen pipe configuration. Most preferably, the guides are in the form of tracks which can interact with a guiding flange set back from the end of the pipe. The tracks preferably have a widened lead-in section at the receiving region such that a floating pipe section may be easily guided into the receiving region. In this region an initial positioning accuracy of +- 20 cm may be sufficient to engage a floating pipe even on rough water. At the holding section, the track may narrow to more accurately position the pipe end part with an accuracy of less than 1 cm. It will of course be understood that these values will depend on the dimensions of the pipes being connected and also on the location. Devices for offshore use may be designed with wider lead-in sections to allow for greater wave movement during pipe handling.

According to a still further aspect, the device may comprise one or more actuators for moving the first and second pipe positioning members from the first position towards the second position in order to bring the pipe ends together for coupling. The skilled person will be well aware of various actuator devices that may be used to achieve such relative movement including but not limited to screw, cam, hydraulic, pneumatic and solenoid type actuators. As has been discussed above, the amount of relative movement required between the first and second pipe positioning members may be relatively small. In the case where no seal is present, this need be no more than a few centimetres and may correspond to about the same distance as the accuracy of the guides at the receiving region. The actuator or actuators may be single acting with the reverse movement taken place by force of gravity or by spring force. Alternatively, actuation may take place in both directions for moving the first and second pipe receiving members towards each other to assume the second position and for moving the first and second pipe receiving members away from each other to assume the first position.

In a preferred configuration, the device is mounted to a vessel and actuators are connected with their first ends to a hull of the vessel and with their second opposite ends to the pipe positioning members. The actuators may be in a substantial horizontal position but are rotatably connected at both ends to either the hull of the vessel or the pipe receiving members to be able to follow vertical or pivoting movement of the pipe receiving members when moving from the first to the second position and vice versa. The first ends may be connected to the hull of the vessel at a substantially horizontal distance away from their corresponding pipe receiving members. Most preferably, hydraulic ram type actuators are used.

The pipe positioning members may each comprise retaining devices for holding the end parts of the floating pipe sections into the pipe positioning members. The end parts of the pipe sections may be pulled into the receiving members using a cable or a chain. This may run through an opening in the pipe receiving members. The retaining device may also comprise means for locking such a cable or chain, thereby securing the end part in the holding region of the pipe receiving member. The invention also provides for a vessel incorporating such a device for attaching a first end part of a first floating pipe section to a second end part of a second floating pipe section to form a floating pipeline. The device may be integrated with the vessel to form a dedicated pipeline construction vessel. Alternatively, the device may be removably mounted to an existing vessel. In this context, the vessel may include but is not limited to a barge, tug, pontoon, raft or semi-submersible and the device may be mounted onboard or outboard according to the configuration of the vessel. The vessel may be provided with storage for additional pipe sections and cranes, hoists and other lifting facilities.

In addition, the invention relates to a method for coupling floating dredging pipe sections to form a pipeline, comprising providing a pipe connecting device having pipe positioning members moveable between a first holding position and a second coupling position, providing first and second pipe sections, guiding an end part of the first pipe section into the first pipe positioning member, guiding an end part of the second pipe section into the second pipe positioning member, moving the pipe positioning members into the second position and connecting the respective end parts of the first and second pipe sections to form a pipeline.

According to an important aspect of the invention, the end parts of the pipe section are guided from a receiving region to a holding region of the pipe positioning members whereby in the receiving region the end parts are relatively loosely located and wherein in the holding region the end parts are relatively accurately located.

Preferably, the guiding takes place by engagement of a guiding element on the pipe sections with a guide or track on the pipe positioning members. The track may be generally funnel-shaped from the receiving region to the holding region.

The method may also comprise causing arcuate movement of the pipe positioning members from the first position to the second position to bring the ends of the pipe sections into engagement. The arcuate movement may be accompanied with

simultaneous lateral or vertical movement of the joint. Preferably, the movement is a single compound movement whereby a minimum number of actuators may be required.

The method may preferably be carried out using a tether to draw in the floating pipe sections from a position where they are floating free of the device to a position within the pipe positioning members. The tether may be a cable or chain operated by a winch or hoist and it may draw the pipe end parts fully into the holding region or merely to the receiving region. In the latter case, additional means such as a mechanical grip may be provided to draw the pipe end part from the receiving region to the holding region and to retain it there. BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

Figure 1 schematically depicts a vessel with a device according to a first embodiment of the invention;

Figure 2 shows a front view of the embodiment of Figure 1 in a coupling position;

Figure 3 schematically depicts a second embodiment of the device;

Figure 4 shows a front view of the embodiment of Figure 3 in a first position; - Figure 5 shows a front view of the embodiment of Figure 3 in a second position;

Figure 6 schematically depicts a third embodiment of the device in plan view in its first position;

Figure 7 shows the device of Figure 6 in the second position;

Figure 8 shows a detail of the end part of a floating pipe section and a pipe positioning member according to the invention; and

Figure 9 schematically depicts a pipeline formed of pipe sections according to the invention.

DETAILED DESCRIPTION

Figure 1 schematically depicts an embodiment of the invention wherein a vessel

100 comprises a device 30 for attaching a first end part 3 of a first floating pipe section 2 to a second end part 13 of a second floating pipe section 12 to form a floating pipeline 1. The device 30 comprises a first pipe positioning member 31 arranged to receive and hold the first end part 3, which first pipe positioning member 31 has a first axial direction which is parallel to a longitudinal axis of the first end part 3 of the first floating pipe section 2 when positioned in the first pipe positioning member 31, and a second pipe positioning member 32 arranged to receive and hold the second end part 13, which second pipe positioning member 32 has a second axial direction which is parallel to a longitudinal axis of the second end part 13 of the second floating pipe section 12 when the pipe section 2 is positioned in the second pipe positioning member 31. The first and second pipe positioning members 31, 32 are moveably mounted to the vessel 100 and arranged to perform a relative movement towards each other from a first position for positioning the end parts 3, 13 of the pipe sections 2, 12, towards a second position for connecting the end parts 3, 13 of the pipe sections 2, 12 to each other. Actuators 37 engage the first and second pipe positioning members 31, 32 for movement along a horizontal guide 40.

Figure 1 depicts an embodiment where the axial directions of the first and second pipe positioning members 31, 32 are mutually parallel and aligned in both the first and second position. The pipe positioning members 31, 32 are shaped as jaws engaging the end parts 3, 13 of the pipe sections 2, 12.

In order to be able to connect the pipe sections 2, 12 to each other to form a pipeline 1, the device 30 is mounted to a vessel 100 in an outboard position, as shown in Figure 1. The pipe positioning members 31, 32 are then positioned into the first position as shown in Figure 1, with the pipe positioning members 31, 32 at a lateral distance from each other in order to accommodate the end parts 3, 13 of the pipe sections 2, 12. A first pipe section 2 and a second pipe section 12 are afloat nearby the vessel whereby the first pipe section 2 is tethered by a chain 20 from hoist 39.

As can be seen from Figure 1, the pipe positioning members 31, 32 are in the form of jaws, open towards the front. Each of the jaws defines a receiving region 7 and a holding region 8. Pipe guides 33 are provided within the jaws of the pipe positioning members 31, 32, extending from the receiving region 7 to the holding region 8. The pipe guides 33 comprise funnel-shaped tracks that are relatively wide at the pipe receiving region 7 and become progressively narrower towards the holding region 8.

For receiving the pipe sections 2 , the pipe positioning members 31, 32 are moved in a vertical direction along a substantially vertical guide 36 such that the pipe receiving regions 7 of each pipe positioning member are at or below the water surface. The floating pipe section 2 is then connected with the hoist 39 through chain 20 and drawn towards the receiving region 7. During drawing-in of the chain 20, the pipe guide 33 provided on the first pipe positioning member 31 engages with a guiding element 6 provided on the end part 3 of the pipe section 2. The pipe section 2 is thus guided towards the holding region 8 of the first pipe positioning members 31. After receiving and positioning the pipe section 2, appropriate locking elements (not shown) are engaged to hold the pipe section 2 at the holding region 8 of the first pipe positioning member 31. Thereafter the chain can be released and the hoist 39 may be used to draw in the second pipe section 12 into the second pipe positioning member 32.

Figure 2 shows a frontal view of the vessel 100 of Figure 1, with the first pipe section 2 and the second pipe section 12 held in their respective first and second pipe positioning members 31, 32. In this depiction, the pipe positioning members 31, 32 have also been moved upwards along the vertical guide 36 to lift the receiving regions 7 above the water surface in order to facilitate coupling. Furthermore, the pipe positioning members 31, 32 have been pushed by actuators 37 towards each other along horizontal guide 40 into a coupling position, whereby connection flanges 4 provided at the extremities of the end parts 3, 13 of the pipe sections 2, 12 abut. In this position, the connection flanges 4 can be connected together with a coupling collar 10 sized to engage and lock over the connection flanges 4 of the abutting pipe sections 2, 12. It will be understood that alternative coupling arrangements may also be provided including bolts, clips, clamps and the like.

After connecting the pipe sections 2 to form a pipeline 1, the pipeline 1 is released from the pipe positioning members 31, 32 by letting chain 20 slack. The pipeline 1 is now guided by the guides 33 and the guiding elements 6 from the holding region 8 back to the receiving region 7 of the pipe positioning members 31, 32 and lowered into the water. Subsequently, the pipe positioning members 31, 32 can be moved into the first position by pulling the first and second pipe positioning members 31, 32 away from each other along the horizontal guide 40 with the actuators 37 to assume the first position.

Figure 3 schematically depicts another embodiment of the vessel 100 with the device 30 whereby the first and second pipe positioning members 31, 32 are pivoted at a hinge axis 35. Other features are generally similar to the first embodiment of Figures 1 and 2 and are provided with similar reference numerals.

According to Figure 3, the first pipe section 2 has been received in first pipe positioning member 31 which is shown in its second coupling position with the guiding element 6 retained by the pipe guides 33 within the holding region 8. Furthermore, the second pipe section 12 has been drawn into the second pipe positioning member 32 by chain 20. In Figure 3, second pipe positioning member 32 is shown in its first holding position. Actuators 37 retain the first and second pipe positioning members 31, 32 in their respective positions.

Figure 4 shows the embodiment of Figure 3 in a front view. As can be seen, each of the first and second pipe positioning members 31, 32 has a longitudinal axis X-X perpendicular to an axial direction Y-Y. In the position shown in Figure 4, the first pipe positioning member 31 is in a vertical position. The second pipe positioning member 32 is at an angle to the vertical whereby an angle a/2 is formed between the axis X-X and the vertical.

Also shown in Figure 4 is coupling collar 10 which is fixed to the end part 3 of first pipe section 2 by a retaining ring 44. The retaining ring 44 includes a pin 46 which allows coupling collar 10 to be opened by pivoting about the pin 46. In its position according to Figure 4, the coupling collar 10 is open, ready to receive the connection flange 4 of the second pipe section 12.

Figure 5 shows the embodiment of Figure 4 in which the second pipe positioning member 32 has been rotated from the holding position to the coupling position by a rotation through the angle a/2. Rotation is achieved by actuation of the actuator 37 associated with the second pipe positioning member 32. In this second position the axial directions Y-Y of the first and second pipe positioning members 31, 32 are mutually parallel and aligned. In this position, the coupling collar 10 may be closed around the aligned connection flanges 4.

The first and second pipe positioning members 31, 32 are also moveably mounted to a vertical guide 36 as in Figure 1. The first and second pipe positioning members 31, 32 can thus be moved in a substantially vertical direction along the vertical guide 36. This movement can allow the coupled pipeline 1 to be lowered to the waterline for release. Alternatively, lowering of the first and second pipe positioning members 31, 32 may take place concurrently with movement from the first position to the second position whereby strain on the first and second pipe positioning members 31, 32 is reduced.

As can also be clearly seen in Figure 5, a gap 34 is provided between the first and second pipe positioning members 31, 32 when in the second position. This allows the coupling collar 10 to pass between the pipe positioning members 31, 32 without interference. This gap 34 is defined as a mutual distance D between the respective guiding elements 6 of each pipe section 2 in the coupled position. The distance D is around 40 cm although the skilled person will understand that this may be selected according to the design of the pipe sections and the location of the guiding elements 6 and in most cases will lie between 20cm and 1 meter.

Figure 6 shows a third embodiment of the invention in a plan view. In this embodiment, the axial direction Y-Y of the first pipe positioning member 31 and the axial direction Y-Y of the second pipe positioning member 32 are in the same plane and define an angle a between them. The axial directions of the first and second pipe positioning members 31, 32 lie in a substantially horizontal plane.

The first and second pipe positioning members 31, 32 are each hingeably connected to a substantially vertical hinge axis 35. The first and second pipe positioning members 31, 32 can thus rotate about their respective hinge axis 35 under control of actuators 37 that push the pipe positioning members 31, 32, towards each other. The actuators 37 used for moving the pipe positioning members are connected with first ends to a hull 101 of the vessel 100 and connected with second opposite ends to the pipe positioning members 31, 32.

For receiving the pipe sections 2, 12 via pipe receiving regions 7, the pipe positioning members 31, 32 can also be moved in a vertical direction along the vertical guide 36 such that the pipe receiving region 7 of each pipe positioning member is at or below the water surface. The floating pipe sections 2, 12 are then connected with the hoist 39 as previously described and drawn towards the receiving region 7. The pipe guides 33 engage with guiding elements 6 provided on the end parts 3, 13 of the pipe sections and the pipe sections 2, 12 are guided towards the holding region 8 of the pipe positioning members 31, 32. After receiving and positioning the pipe sections, the chain 20, than acting as a retaining device, is secured to hold the pipe sections 2, 12 in the pipe positioning members 31, 32.

Figure 7 shows a plan view of the embodiment of Figure 6 in the coupling position wherein the axial directions of the first and second pipe positioning members 31, 32 are mutually parallel and aligned, the pipe positioning members 31, 32 have been moved by a relative rotation through the angle a.

In this case, the pipe positioning members 31, 32 have also been moved upwards along the vertical guide 36 to lift the receiving regions 7 above the water surface in order to facilitate the coupling. The skilled person will however understand that coupling at the waterline may also be carried out and that the vertical guide 36 and its related actuation mechanism (not shown) may be omitted.

Movement of the pipe positioning members 31, 32 to the position of Figure 7 is by actuators 37 acting towards each other such that in the second position, the connection flanges 4 provided at the extremities of the end parts 3, 13 of the pipe sections 2, 12 abut. The connection flanges 4 can then be connected with a coupling collar 10 as previously described or with bolts and nuts.

As in the previous embodiments, a gap 34 is provided between the first and second pipe positioning members 31, 32 when in the second position, in order to allow sufficient space for joining the connecting flanges 4. Although the pipe sections in

Figures 6 are shown angled towards each other in a direction away from the vessel 100, it will be understood that the device may also be configured such that the first and second pipe positioning members 31, 32 pivot in the opposite sense.

Figure 8 shows in greater detail a floating pipe section 2 with its first end part 3. Connection flange 4 is provided at the extremity of the end part 3 and guiding element 6 is located adjacent to and spaced from the connection flange 4. The guiding element 6 is a flange which protrudes in an outward radial direction around the outer

circumference of the end part 3. The guiding element 6 has a diameter that is slightly larger than the diameter of the connection flange 4. Its diameter is also slightly smaller than that of the pipe section 2 to avoid interference when stacking pipes. In this embodiment, the flange 4 and guiding element 6 are retrofitted to an existing pipe section 2 having a conventional connection flange 4A. The connection is by welding but the skilled person will understand that bolts or the like may also be used as long as they do not interfere with the guiding function.

Figure 8 also depicts how the guiding element 6 is received in the receiving region 7 of the first pipe positioning member 31. At the receiving region 7 the pipe guide 33 has a width of around 30 cm whereby the guiding element 6 can easily enter, even under rough conditions. Moving towards the receiving region, the pipe guide 33 narrows to a width of around 3 cm, corresponding to the width of the guiding element 6 and ensuring accurate positioning in the axial direction Y-Y.

Figure 9 depicts a pipeline 1 formed of pipe sections 2, 12 according to the invention. The pipe sections 2, 12 are connected by a coupling collar 10 that engages and locks the connection flanges 4. The coupling collar 10 is provided at one free end part 3, 13 of the pipe section and is retained by retaining ring 44 and pin 46 which are mounted to the end section 3 between guiding element 6 and connection flange 4. It can also be seen that the end section 3 is slightly longer in this respect than end section 13.

Thus the invention has been described in detail. Nevertheless, the skilled person will recognize that these embodiments are susceptible to various modifications and alternative forms well known to those of skill in the art without departing from the spirit and scope of the invention as defined by the attached claims.

LIST OF ELEMENTS

1 pipeline

2 first floating pipe section

3 first end part of floating pipe section

4 flange

6 guiding element

7 receiving region

8 holding region

10 coupling collar

12 second floating pipe section

13 second end part

20 chain

30 pipe connection device

31 first pipe positioning member

32 second pipe positioning member

33 pipe guide

34 gap

35 hinge axis

36 vertical guide

37 actuator

39 hoist

40 horizontal guide

44 retaining ring

46 pin

100 vessel

101 hull

Claims

1. A pipe connection system for the coupling of floating pipe sections (2) to form a floating pipeline (1), comprising:

a plurality of pipe sections (2), each pipe section having first and second end parts comprising a connection flange (4) and a guiding element (6) adjacent to and spaced from the connection flange (4);

a pipe connection device (30) comprising first and second jaws (31, 32), moveably mounted relative to each other, each jaw having guides (33), shaped to interact with the guiding elements (6) to guide a respective pipe end part (3) from a receiving region (7) of the jaws to a holding region (8) of the jaws (31, 32); and

an actuator device (37) arranged to move the jaws (31, 32) relative to each other to bring together in alignment, the connection flanges (4) of two pipe sections (2) held in the holding region (8) of the jaws (31, 32).

2. System according to claim 1, wherein the guides have a funnel-like configuration to lead the guiding elements from a relatively open guide at the receiving region to a relatively narrow guide in the holding region.

3. System according to any of the preceding claims, further comprising a plurality of coupling collars, each sized to engage a pair of connection flanges (4) of two pipe sections (3) placed in alignment.

4. System of claim 17, wherein the coupling collars are hingedly connected to respective first end parts of each pipe section.

5. System according to any of the preceding claims, wherein the pipe connection device is the device of any of claims 9 to 23.

6. Floating pipe section (2) having a first and a second end part (3, 13), wherein at least one end part (3) is provided with a connection flange (4) at its extremity and a guiding element (6) adjacent to and spaced from the connection flange (4).

7. Floating pipe section according to claim 6, whereby the guiding element (6) comprises a flange protruding in an outward radial direction around the outer circumference (9) of the pipe section (2).

8. Floating pipe section according to claim 6 or claim 7, further comprising a coupling collar (10) retained on a first end part (3) for movement between an open position and a coupling position.

9. A pipe connection device (30) for attaching a first end part (3) of a first floating pipe section (2) to a second end part (13) of a second floating pipe section (12) to form a floating pipeline (1), wherein the device (30) comprises:

a first pipe positioning member (31) arranged to receive and hold the first end part (3), the first pipe positioning member (31) having a first axial direction which is parallel to a longitudinal axis of the first end part (3) when positioned in the first pipe positioning memb er (31 ),

a second pipe positioning member (32) arranged to receive and hold the second end part (13), the second pipe positioning member (32) defining a second axial direction which is parallel to a longitudinal axis of the second end part (13) when positioned on the second pipe positioning member (31),

wherein the first and second pipe positioning members (31, 32) are moveably mounted and arranged to perform a relative movement towards each other from a first holding position for positioning the end parts of the pipe sections, towards a second coupling position for connecting the end parts of the pipe sections to each other to form a pipeline.

10. Device according to claim 9, wherein the axial directions of the first and second pipe positioning members (31, 32) are mutually parallel and aligned in both the first and second position.

11. Device according to claim 9 or 10, wherein in the first position the axial directions of the first and second positioning members (31, 32) are at a mutual angle a greater than 0°, and in the second position the axial directions of the first and second pipe positioning members (31, 32) are mutually parallel and aligned.

12. Device according to any of the claims 9-11, wherein the first and second pipe positioning members (31, 32) each have a longitudinal axis perpendicular to the axial direction, and wherein the longitudinal axes define a V-shape in the first position and the relative movement comprises a relative rotation of the first and second pipe positioning members (31, 32) about a generally horizontal axis through the angle a.

13. Device according to claim 12, wherein in the first position, the axial direction of the first pipe positioning member (31) and the axial direction of the second pipe positioning member (32) lie in a generally horizontal plane and the relative movement comprises a relative rotation of the first and second pipe positioning members (31, 32) about a generally vertical axis through the angle a.

14. Device according to any of the claims 11-13, wherein the angle a is in the range of 0° < a < 30°.

15. Device according to any of the claims 9-14, the device (30) comprising one or more actuators (37) for moving the first and second pipe positioning members (31, 32) between the first position and the second position.

16. Device according to any of the claims 11-15, wherein the first and second pipe positioning members (31, 32) are hingeably connected to a hinge axis (35), whereby the first and second pipe positioning members (31, 32) rotate about the hinge axis (35) when being moved from the first position to the second position.

17. Device according to any of the claims 9-16, wherein the device (30) further comprises a transverse guide (36) for guiding the first and second pipe positioning members (31, 32) for movement in a direction generally perpendicular to an axis of the pipeline.

18. Device according to claim 15 or 16, wherein the hinge axis (35) is moveably connected to the transverse guide (36).

19. Device according to any of the claims 9-18, wherein a gap (34) is provided between the first and second pipe positioning members (31, 32) when in the second position, in order to allow a connection member (10) to pass between the pipe positioning members (31, 32) for joining connecting flanges provided at each extremity of each first and second pipe sections (2).

20. Device according to any of the claims 9-19, whereby each pipe positioning member (31, 32) is provided with a track (33) for guiding a respective end part from a receiving region of the pipe positioning member to a holding region of the pipe positioning member.

21. Device according to any of the claims 9-20, whereby the device (30) is provided with hoisting means (39) for drawing the first and second end parts into the pipe positioning members (31, 32).

22. Device according to any of the claims 9-21, wherein the pipe positioning members (31, 32) each comprise retaining devices (40) for holding the end parts of the floating pipe sections in a holding region of the respective pipe positioning member (31, 32).

23. Device according to any of the claims 9-22, wherein in the second position, the first and second pipe positioning members (31, 32) are at a mutual distance D, wherein D is defined by the distance between the respective guiding elements of each pipe section (2), wherein D > 20 cm and preferably less than 1 meter.

24. A vessel comprising the device according to claim 9-23, whereby the device (30) is mounted to the vessel (100), preferably at an outboard position.

25. Vessel according to claim 24, comprising one or more actuators according to claim 8, wherein the actuators (37) are connected with first ends to a hull (101) of the vessel (100) and connected with second opposite end parts (3) to the pipe positioning members (31, 32).

26. Method for coupling floating dredging pipe sections (2) to form a pipeline (1), comprising:

- providing a device (30) according to any one of the claims 1 - 17,

- positioning the pipe positioning members (31, 32) into the first position,

- providing a first pipe section (2) and a second pipe section (2)

- guiding the end part (3) of the first pipe section (2) into a holding position of the first pipe positioning member (31),

- guiding the end part (3) of the second pipe section (2) into a holding position of the second pipe positioning member (32),

- moving the pipe positioning members (31, 32) into the second position,

- connecting the respective end parts (3) of the first and second pipe sections (2), forming a pipeline (1).

27. Method according to claim 26, whereby moving the pipe positioning members (31, 32) into the second position, comprises moving the first and second pipe positioning members (31, 32) in a substantial vertical direction, the first position being higher than the second position.

28. Method according to claim 26, whereby moving the pipe positioning members (31, 32) into the second position, comprises moving the first and second pipe positioning members (31, 32) in a substantial horizontal direction.

29. Method according to any of claims 26-28, whereby moving the first and second pipe positioning members (31, 32) into the second position comprises pushing the first and second pipe positioning members (31, 32) towards each other to assume the second position.

30. Method according to any of claims 26-29, whereby connecting the respective end parts (3) of the first and second pipe sections (2) comprises connecting the end parts (3) by a connection member catching connection flanges (4) provided at extremities of the end parts (3) of each pipe section (2).

31. Method according to claim 30, whereby the connection member (10) comprises a coupling collar, sized to engage and lock a pair of connection flanges (4) of two adjoining pipe sections (2). 32. Method according to any of claims 26-31, further comprising releasing the pipeline (1) from the pipe positioning members (31,

32).

33. Method according to any of claims 26-32, further comprising moving the pipe positioning members (31, 32) back into the first position.