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1. WO2007003937 - APPARATUS AND METHOD FOR SEPARATING FLANGES

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CLAIMS

1. Apparatus for spreading flanges of pipes comprising:
at least one bolt hole engaging device;
a force transmission system arranged for selective coupling with the at least one bolt hole engaging device and capable of exerting a force thereon for selective movement of the flanges relative to one another, wherein the bolt hole engaging device comprises
an expandable member arranged so that in use it is at least partially accommodated within a bolt hole before expansion, and
an expander means arranged to expand the expandable member such that at least a portion of an outer surface of the expandable member is expanded to contact the bolt hole.

2. Apparatus according to claim 1 , wherein the expander means comprises at least one wedge shaped member such as a frustoconical member and an actuator means for causing relative movement between the wedge shaped member(s) and the expandable member and wherein the wedge shaped member is arranged such that relative movement between wedge shaped member and the expandable member causes the expandable member to expand.

3. Apparatus according to claim 2, wherein the actuator means comprises a screw-threaded device and acts to urge the expandable member axially relative to the wedge shaped member towards the larger diameter end of the wedge shaped member to radially expand the expandable member.

4. Apparatus according to claim 3, wherein the screw threaded device comprises a nut and a threaded portion provided on a part of the expander means, wherein the nut has a collar, which collar is arranged to engage an end face of the expandable member.

5. Apparatus according to any preceding claim, wherein a second bolt hole engaging device is provided for insertion into a bolt hole axially aligned with the first bolt hole.

6. Apparatus according to any preceding claim, wherein the
expandable member is arranged to contact the bolt hole in at least three radially spaced points following expansion thereof.

7. Apparatus according to any preceding claim, wherein substantially an entire circumference of the expandable member is arranged to contact the bolt hole following expansion thereof

8. Apparatus according to any preceding claim, wherein the expandable member has an inner bore to accommodate at least a portion of the expander means.

9. Apparatus according to any preceding claim, wherein the expandable member comprises a plurality of portions that are movable relative to one another to radially expand and engage the bolt hole.

10. Apparatus according to claim 9, wherein the portions have tapered inner bearing surfaces that are shaped to match an outer profile of the expander means.

11. Apparatus according to any of claims 1 to 8, wherein the
expandable member has one or more slits extending through a sidewall thereof in order to allow for expansion of the expandable member.

12. Apparatus according to claim 11 , wherein the slits extend from an end of the expandable member and are circumferentially spaced around the expandable member and circumferentially adjacent slits extend from alternate ends of the expandable member.

13. Apparatus according to any preceding claim, wherein a single expander means is operable with several sizes of expandable members in order to engage different widths of bolt holes.

14. Apparatus according to any preceding claim, wherein the force transmission system comprises two arms that are each connectable to a respective bolt hole engaging device at one end and to a driving mechanism at the other end.

15. Apparatus according to claim 14, wherein the driving mechanism is a screw-threaded device that is capable of exerting an axial force to separate the two bolt hole engaging devices.

16. Apparatus according to claim 14 or claim 15, wherein the force transmission system is provided with a spacer bar connectable between pivot points on the arms and wherein the length of the spacer bar is adjustable to suit the distance between the flanges and is lockable in a number of positions once the desired length has been determined.

17. Apparatus according to claim 16, wherein the length of the spacer bar is adjustable to alter a leverage force exerted by the force
transmission system.

18. Apparatus according to claim 16 or claim 17, wherein the length of the driving mechanism is adjustable to enable use of the force
transmission system on a range of flange widths.

19. Apparatus according to any of claims 1 to 13, wherein the force transmission system comprises a piston such as a hydraulically operable ram that is capable of exerting an axial force to separate the two bolt hole engaging devices that are attached to the flanges.

20. Apparatus according to claim 19, wherein the or each bolt hole engaging device has a hydraulic piston chamber and a piston.

21. Apparatus according to claim 20, wherein each piston has an end face that is provided with a connection means to connect with an opposing piston.

22. A method for spreading flanges of pipes comprising the steps of:
providing a bolt hole engaging device comprising an expandable member;
arranging the expandable member at least partially within a bolt hole on a flange;
actuating an expander means to expand an outer surface of the expandable member into contact with the bolt hole;
providing a force transmission system to act on the bolt hole engaging device; and
actuating the force transmission system to exert a force on the bolt hole engaging device to move the flanges relative to one another.

23. A method according to claim 22, including the step of providing a wedge shaped expander means, driving the frustoconical expander means and the expandable member relative to one another and thereby expanding the expandable member.

24. A method according to claim 23, including providing a threaded actuator means comprising a nut on a screw thread and including the step of turning a nut on a screw thread to cause the nut to act on the frustoconical expander means to move it relative to the expandable member.