GB2147072A

GB2147072A - Pipe connectors

Info

Publication number: GB2147072A
Application number: GB08420267A
Authority: GB
Inventors: Ian Harold Hignett; Anthony John Asbury
Original assignee: HUNTING OILFIELD SERVICES
Current assignee: HUNTING OILFIELD SERVICES
Priority date: 1983-09-21
Filing date: 1984-08-09
Publication date: 1985-05-01
Also published as: GB8325225D0; GB8420267D0

Abstract

A connector for connecting the ends of two tubular elements, e.g. pipes, comprises a plurality of axially extending elements (5) which are associated with the end of one tubular member (1) and are operable to engage the end of the other tubular member (3) and move the tubular members axially to bring the two into engagement. The elements (5) are connected to an annular body (6) which is axially slidable relative to an annular member (10) itself axially slidable on tubular member (1), the body (6) and member (10) being axially movable to cause radial and axial movement of the elements (5). Movement of the body (6) and member (10) is obtained by pressurization of chambers (11, 16) and (12, 17) under the control of a valve member (20) to cause the required movement of elements (5) automatically. <IMAGE>

Description

SPECIFICATION Improvements in and relating to connectors for tubular members The present invention relates to a connector for connecting the ends of two tubular members and which is mounted on the end of one tubular member and automatically engages the end of the other tubular member and brings the two tubular members into engagement.

Such connectors are of particular utility where the tubular members to be connected are in hazardous environments, for example sub-sea for connecting the various tubular members used in oil or gas well drilling and production.

According to the present invention, there is provided a connector for connecting the ends of two tubular members comprising a plurality of axially extending elements associated with the end of one tubular member, which are adapted for engaging the end of the other tubular member when located adjacent the end of the one tubular member, and which are operable to bring the ends of the tubular members into engagement with one another, the axially extending elements being movable relative to the one tubular member both axially and radially, means being provided for causing movement of the elements relative to the one tubular member.

Advantageously the elements are connected to an annular body, preferably by flexible portions which enable the elements to move radially relative to the annular body. The annular body may be mounted on an annular member mounted on a tubular portion of or for connection to the end of the one tubular member. The annular member may be movable axially relative to the tubular portion causing axial movement of the elements and the annular body may be movable axially relative to the annular member for causing radial movement of the elements. Cam means may be provided between the elements and the annular member which interact to cause radial movement of the elements on axial movement of the annular body relative to the annular member.

The annular body and member may be moved relative to the tubular portion by application of fluid under pressure to the connector, chambers being defined between the body and member and member and tubular portion which are connectable to a source of fluid under pressure.

Biasing means may be provided for biasing the connector into an initial condition in which the elements are in a radially inner contracted position and an axially retracted position for engaging the end of the other tubular member and holding it in engagement with the end of the tubular portion. Application of fluid under pressure to the connector then causes the annular member to move axially relative to the tubular portion and the annular body to move axially relative to the annular member to move the element radially and axially to an axially extended radially expanded position ready to engage the end of the one tubular member.In this condition, valve means move automatically to cause the annular body to move relative to the annular member back to its original relative position causing the elements to move radially to their contracted position to engage the other tubular member and then causes the annular member to move axially relative to the tubular portion back to its original position causing the elements to move back to their axially retracted position bringing the end of the other tubular member into engagement with the end of the tubular portion.

Advantageously the valve means comprises a generally cylindrical valve member located between the tubular portion and the annular member and which is axially movable relative thereto.

Preferably latching means is provided between the elements and the annular member preventing radial movement of the elements when in their radially inner contracted position and which is released by relative movement of annular body and annular member.

Locking means may also be provided for locking the annular member against axial movement relative to the tubular portion when the elements are in their axially retracted position.

The locking means are preferably released on application of fluid under pressure to the connector, before movement of the member and body is initiated.

An embodiment according to the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a sectional view on the axis of an embodiment of connector according to the present invention, showing the connector in a condition in which the two tubular members connected thereby are engaged together; Figures 2, 3 and 4 are sectional views corresponding to Fig. 1 showing the connector in three operative conditions; Figure 5 is an enlarged sectional view of part of the connector of Fig. 1; Figure 6 is a plan view of part of the connector of Fig. 1, showing the elements thereof; and Figures 7 and 8 are sectional views of other embodiments of connectors according to the present invention.

The connector shown in Figs. 1 to 6 comprises a tubular portion 1, which may be formed or made integrally on the end of a tubular member or may, as shown, be made separately for connection by flange 2 to the end of a tubular member (not shown), which is to be connected to a tubular portion 3 which may also be made or formed integrally with a tubular member or may, as shown, be formed separately for connection by flange 4 to the tubular member.

A plurality of elements 5 are mounted on the tubular portion 1 for axial and radial movement relative thereto for engaging tubular portion 3 and bringing it into engagement with the end of tubular portion 1, as shown in Fig. 1. Elements 5 are connected to an annular body 6 by flexible portions 7 of reduced thickness and which permit the elements 5 to flex relative to body 6. As shown in Fig. 6, the elements 5 form a generally cylindrical shell around the end of tubular portion 1, the shell being split axially to define the elements 5. As shown twelve such elements 5 are provided although it will be appreciated that more or less such elements may be provided depending on the connector, and indeed that the axially directed splits between the elements 5 may be wider so that the elements 5 are circumferentially spaced apart.At their free ends, the elements 5 are provided with end portions 5a which diverge to form a guide surface for assisting initial positioning of portion 3 relative to portion 1. For engaging the end of portion 3, each element 5 is provided with a claw 8 which is adapted to engage behind an annular enlargement 9 on the end of portion 3.

Annular body 6 is mounted to be axially slidable relative to an annular member 10 which is in turn mounted on tubular portion 1 for axial sliding movement relative thereto.

Body 6 is movable relative to member 10 for causing radial movement of the elements 5, movement of body 6 being obtained by supplying fluid under pressure to one or other of chambers 11 and 12 defined between the body 6 and member 10. Radial movement of the elements 5 relative to body 6 is obtained by the provision of cam means between member 10 and each element 5 which interact on relative axial movement of the member and body to cause the required radial movement of the elements 5. As shown each element 5 is provided with a cam projection 14 and member 10 is provided with an annular projection 13. As body 6 moves to the right hand side relative to member 10 each projection 14 rides up onto projection 13 to cause radially outward movement of the elements 5.

Projections 14 also form part of a latching mechanism for preventing radially outward movement of the elements 5 until body 6 moves relative to member 10. As shown projections 14 are received in a recess 15 in member 10 which at the left hand end is undercut, the corresponding end of projection 14 being correspondingly shaped.

Movement of member 10 relative to tubular portion 1 is obtained by pressurisation of one or other of chambers 16 and 17 (Fig. 5) defined between member 10 and portion 1.

Member 10 is also lockable axially relative to portion 1 by locking means which, as shown, comprises a plurality of locking members 18 housed in portion 1 and movable radially into an annular recess 19 provided adjacent one end of member 10.

For controlling supply of fluid under pressure to the chambers 11, 12 and 16,17, valve means is provided comprising a generally cylindrical valve member 20 which is axially slidable relative to tubular portion 1 and, as shown, defines the inner wall of annular chambers 16 and 17.

In its initial condition, the connector is as shown in Fig. 1 with the elements 5 in their axially retracted radially contracted positions, the elements 5 being latched against radial outward movement by interengagement of projections 14 with recess 15 and member 10 being locked against axial movement relative to portion 1 by engagement of locking members 18 in recess 19.

A tubular portion 3 to be engaged with tubular portion 1 is initially positioned adjacent the end of tubular portion 1, or vice versa, for example as shown in Fig. 2. The connector is then activated by application of fluid under pressure, for example in the range 1000-5000 psi, to inlet 21. Initially fluid flows from inlet 21 to passages 22 each connected to a chamber 23 defined in part by a respective locking member 18 to cause radial inward movement of each member 18 to disengage it from member 10. As each member 18 is moved radially inwardly against the bias of a spring 20, chamber 23 comes into communication with a passage 24 which communicates with chamber 16 between member 10 and tubular portion 1. Chamber 16 is also in communication via passage 25 with chamber 11 between member 10 and body 6.Chambers 12 and 17 are provided with springs 1 2a, 17a, e.g. disc or helical springs, which bias member 10 and body 6 against the action of the pressure of fluid in chambers 11 and 16 and the biasing forces are arranged relative to the areas of the chambers such that initially member 10 is moved to the left hand side of Fig. 1 to move the elements 5 towards their axially extended positions. Following initiation of movement of member 10, for example after about 30% of the total axial movement of member 10, body 6 then moves to the right hand side relative to member 10 to free projections 14 from recess 15 and move the projections 14 onto projections 13 to cause the elements 5 to move to their radially expanded positions, as shown in Fig. 2. Movement of member 10 continues until the portion 1 Oa of member 10 separating chambers 16 and 17 has just moved past passage means 26 in valve member 20. At this point the fluid under pressure in chamber 16 communicates with passage means 26, which may comprise one or a plurality of radial passages. Passage means 26 communicates by a plurality of axial or helical passages 27 defined between valve member 20 and tubular portion 1 with a chamber 28 at the right end of valve member 20 and defined by valve member 20 and an annular recess in portion 1. As soon as the pressure in chamber 28 reaches a pre-set level, valve member 20 is moved towards the left hand side, against the bias of spring means 29 and this movement establishes direct communication betweem chamber 16 and chamber 28 and moves passage means 26 past portion 1 0a back into communication with chamber 17.

Movement of the valve member 20 to the left hand side is limited by abutment of a step 30 provided on the member 20 with portion 1.

Because of direct communication between chambers 16 and 28 flow along passage means 26, 27 reverses and fluid under pressure is then supplied to chamber 17 and via passage 31 to chamber 12. The areas of chambers 12 and 17 relative to those of chambers 11 and 16 together with the biasing forces provided by the springs 12a, 17a is such that, first, body 6 is moved in the left hand direction relative to member 10 to permit the elements 5 to move back to their radially inner contracted position (Fig. 4) in which the claws 8 should be in a position to engage behind the enlargement 9 of the tubular portion 3.Thereafter member 10 is moved towards the right hand side relative to member 1 to move the elements 5 back to their axially retracted positions and to cause the claws 8 to engage behind the enlargement 9 and draw the two tubular portions 1,3 into full engagement, as shown in Fig. 1, and to hold the portions in full engagement.

Finally, on removal of the pressurised fluid supply, the locking members 1 8 will return under the force of the biasing springs 20 to their locking positions engaging in the recess 1 9 of member 10. Movement of the locking members 19 to their locking positions causes passage 24 to communicate with the spring chambers below the locking members, which are vented by passages 33, completing depressurisation of chamber 16 and partially depressurising chamber 28. Depressurisation of chamber 28 is completed through passage means 27,26 chamber 17 and vent pasage 32. Member 20 will thus return to its original position under the bias of spring 29.

While as shown, vent passages 32,33 feed into the interior of portion 1, they may alternatively feed externally of the connector.

It will be appreciated that means may be provided associated with the locking members 18 for providing a visual or other indication that the members 18 have engaged fully with member 10 as this then provides an indication that tubular portion 3 is fully engaged with tubular portion 1.

Although not explicitly described, it will be appreciated that seals of any suitable material may be provided between the various sliding surfaces to ensure sealing where required.

In use of the above described connector, when the tubular members connected thereby contain fluid under pressure, the resulting tensile loads on the connector may be balanced by flow of the fluid through vent passage 32 into chamber 17 to react on the portion 1 0a of member 10 and into chamber 12 to react on member 6.

A modification of the above described connector is shown in Fig. 7. In this embodiment, parts corresponding to parts of the embodiment of Figs. 1 to 6 have been assigned the same reference numerals.

Axial and radial movement of the elements 5 of this embodiment is obtained in the same way as in the preceding embodiment by relative movement of body 6 and member 10 relative to tubular portion 1 by pressurization of chambers 11,16 and 12,17. As in the preceding embodiment, radial movement of the elements 5 is obtained by interaction of cam projections 13,14 on member 10 and elements 5 respectively. However, in this embodiment, the latching means for preventing radial outward movement of elements 5 when in their radially retracted position is provided by an axially projecting nose 40 on each element which engages in a groove 41 on member 10, engagement being obtained as the elements 5 are moved in their radially retracted position to the right hand side relative to member 10.As a result of this modification, pressurization of chamber 11 causes movement of body 6 to the left hand side relative to member 10 (rather than to the right hand side as in the previous embodiment) to cause disengagement of the noses 40 from the groove 41 and then radially outward movement of the elements 5 by interaction of projections 13,14. Pressurization of chamber 12 reverses this relative movement.

The connector of Fig. 7 has advantages where it is desirable in use for the connector to break before one of the tubular members, e.g. a riser, to which the connector is attached breaks. If, in use, excess tension is applied across the connector, the springs 12a in chamber 12 will be compressed and at a predetermined maximum tension the compression will reach such a point that the noses 40 will be released from the groove 41 to permit the elements 5 to move radially outwardly to release tubular portion 3. It will appreciate that this breakage of the connector in fact does no damage to the connector which can be re-used immediately thereafter.

A further modification of the embodiment of Figs. 1 to 6 is shown in Fig. 8 and in the connector of Fig. 8 like reference numerals have been used for like parts. In the embodi ment of Fig. 8, the elements 5 are provided with cam projections 14 which, as in the embodiment of Figs. 1 to 6, engage in an undercut recess 15 to latch the elements 5 when in their radially retracted position. However, in this embodiment, there is no corresponding cam projection 13 on the tubular member 10, the projections 14 merely ride up on to portion 13a of the circumferential surface of member 10 adjacent the recess 15 and this causes the required radial outward movement of the elements 5. Additionally, the locking member 18a are, in this embodiment, mounted on member 10 rather than on tubular portion 1 although they operate in exactly the same way as the locking member 18 of the embodiment of Figs. 1-6.As shown, each locking member 18a in operation engages behind a shoulder 42 on portion 1. The fluid inlet 21 is provided in member 10 and communicates with passages 22a each opening into a chamber 23a defined in part by the locking member 18a. Pressurization of chamber 23a causes radial outward movement of the locking member 18a against the bias of spring 20a. When member 18a has been released from shoulder 42, chamber 23a comes into communication with passage 24 which opens into a radial duct communicating with chambers 11,16, as in the embodiment of Figs. 1 to 6.

The components of the above described connectors may be made from any suitable materials, depending on the particular use of the connector. For use sub-sea, particularly at depths beyond those at which a diver can go, the parts of the connector may be made of high tensile stainless or carbon steel and the seals may be metal seals and/or made of a suitable high grade elastomer.

Claims

1. A connector for connecting the ends of two tubular members comprising a plurality of axially extending elements associated with the end of one tubular member, which are adapted for engaging the end of the other tubular member when located adjacent the end of the one tubular member, and which are operable to bring the ends of the tubular members into engagement with one another, the axially extending elements being movable relative to the one tubular member both axially and radially, means being provided for causing movement of the elements relative to the one tubular member.

2. A connector as claimed in claim 1, wherein the elements are connected to an annular body mounted for axial movement relative to the one tubular member for causing radial movement of the elements between a radially inner contracted position for engaging the end of the other tubular member and a radially expanded position.

3. A connector as claimed in claim 2, wherein the elements are connected to the annular body by flexible portions which flex as the members move between their radially inner contracted position and radially expanded position.

4. A connector as claimed in either claim 2 or claim 3, wherein the annular body is mounted for axial movement on an annular member mounted for axial movement on a tubular portion of or for connection to the end of the one tubular member, the annular member being movable axially for causing axial movement of the elements between an axially retracted position for engaging the end of the other tubular member and holding it in engagement with the end of the tubular portion and an axially extended position.

5. A connector as claimed in claim 4, wherein cam means are provided between the elements and the annular member for causing radial movement of the elements on axial movement of the annular body relative to the annular member.

6. A connector as claimed in either claim 4 or claim 5, wherein the annular body and annular member are moved relative to the tubular portion by application of fluid under pressure to the connector, chambers being defined between the body and member and between the member and tubular portion which are connectable to the fluid under pressure.

7. A connector as claimed in claim 6, including valve means for controlling flow of fluid to the chambers which are arranged so that on application of fluid under pressure to the connector, the annular member and annular body will move axially relative to the tubular portion to cause the elements to move to their radially expanded axially extended position ready to engage the end of the one tubular member, the valve means then moving automatically to change the supply of fluid under pressure to the chambers to cause the annular body to move relative to the annular member back to its original position causing the elements to move radially to their contracted position to engage the other tubular member and then causing the annular member to move relative to the tubular portion back to its original position causing the elements to move back to their axially retracted position bringing the end of the other tubular member into engagement with the end of the tubular portion.

8. A connector as claimed in claim 7, wherein the valve means comprises a generally cylindrical valve member located between the tubular portion and the annular member and which is axially movable relative thereto.

9. A connector as claimed in any one of the preceding claims, including latching means for preventing radial movement of the elements when in their radially inner contracted position.

10. A connector as claimed in claim 9, wherein the latching means are provided between the elements and the annular member and are released by relative movement of the annular body and annular member.

11. A connector as claimed in any of claims 4 to 10, comprising locking means for locking the annular member against axial movement relative to the tubular portion when the elements are in their axually retracted position.

12. A connector as claimed in claim 11, wherein the locking means are arranged to be automatically released before movement of the annular body and annular member is initiated.

13. A connector substantially as herein described with reference to Figs. 1 to 6 of the accompanying drawings.

14. A connector substantially as herein described with reference to either Fig. 7 or Fig. 8 of the accompanying drawings.