Internal line-up clamps for welding pipes

Patent metadata

Field	Value
Publication number	US-9962795-B2
Application number	US-201414894990-A
Country	US
Kind code	B2
Filing date	May 23, 2014
Priority date	May 30, 2013
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

An internal line-up clamp for welding pipe lengths end-to-end includes a clamp ring made up of a plurality of clamp ring elements that are angularly distributed around the circumference of the clamp ring. The clamp ring elements are divided into mutually opposed groups that are interdigitated such that the clamp ring elements alternate from one group to the other around the circumference of the clamp ring. A longitudinally-acting actuator system drives relative longitudinal movement of the groups to effect clamping expansion of the clamp ring by wedging interaction between the circumferentially-alternating clamp ring elements of the groups. By expanding the clamp ring in alignment with a weld plane between the abutting ends, the same clamp ring may be used to align the pipe lengths and to back a weld between them.

First claim

The invention claimed is:

1. An internal line-up clamp for welding pipe lengths end-to-end, the clamp comprising:
a clamp ring made up of a plurality of clamp ring elements that are angularly distributed around the circumference of the clamp ring and are divided into mutually interacting groups, which groups have wedging interaction and are interdigitated such that the clamp ring elements alternate from one group to the other around the circumference of the clamp ring, wherein neighbouring clamp ring elements in the clamp ring are linked by complementary connectors for relative movement along abutting edges of the clamp ring elements to hold the elements together during expansion and contraction of the clamp ring; and a longitudinally-acting actuator system arranged to drive longitudinal movement of the groups relative to each other, so that the relative longitudinal movement of the groups causes clamping expansion of the clamp ring by wedging interaction between the circumferentially-alternating clamp ring elements of the groups.

2. The clamp of claim 1 , wherein both groups are movable longitudinally relative to a support structure of the clamp.

3. The clamp of claim 2 , wherein the actuator system is arranged to synchronise longitudinal movement of the groups through a weld plane that is orthogonal to the direction of longitudinal movement.

4. The clamp of claim 1 , wherein the actuator system comprises a pair of opposed actuators each acting on a respective one of the groups.

5. The clamp of claim 1 , wherein at least one actuator of the actuator system is positioned longitudinally outboard of the clamp ring.

6. The clamp of claim 5 , wherein the actuator is connected to a clamp ring element by a linkage that applies a radially outward force component to the clamp ring element when forced longitudinally by the actuator.

7. The clamp of claim 6 and comprising a guide on the actuator that is positioned to guide movement of the linkage.

8. The clamp of claim 1 , wherein the actuator system extends around a central longitudinal axis of the clamp.

9. The clamp of claim 8 , wherein an actuator of the actuator system is annular and surrounds a central shaft of the clamp.

10. The clamp of claim 1 , wherein at least one actuator of the actuator system is double-acting to expand the clamp ring for clamping and to contract the clamp ring for insertion and removal.

11. The clamp of claim 1 , wherein the complementary connectors comprise connector formations on the abutting edges on the clamp ring elements.

12. The clamp of claim 11 , wherein a connector formation extends along an abutting edge of a clamp ring element.

13. The clamp of claim 11 , wherein the clamp ring elements are held together against separation.

14. The clamp of claim 1 , wherein abutting edges of the clamp ring elements are chamfered such that the clamp ring elements taper radially inwardly in cross-section through the clamp ring.

15. The clamp of claim 1 , wherein each clamp ring element comprises a radially-inner support surmounted by a radially-outer pad, which pad is outwardly arcuate in cross-section.

16. The clamp of claim 1 , wherein at least an outer face of each clamp ring element comprises a copper alloy, a ceramic or other weld-backing material.

17. The clamp of claim 1 , wherein an outer face of at least one clamp ring element has at least one groove or other opening that is positioned to lie under or adjacent to a weld location during welding and that communicates with a system for injecting a shielding gas.

18. A method of aligning pipe lengths disposed end-to-end for welding, comprising:
positioning an internal line-up clamp to bridge abutting ends of the pipe lengths; and
expanding a clamp ring of the clamp to effect clamping of the pipe lengths;
wherein the clamp ring is expanded to apply clamping force to the pipe lengths by driving relative longitudinal movement between interdigitated, mutually wedging interacting groups of clamp ring elements to cause wedging interaction by relative movement along abutting edges linked by complementary connectors of neighbouring clamp ring elements of the clamp ring, the complementary connectors between the abutting edges holding the clamp ring elements together during expansion and contraction of the clamp ring.

19. The method of claim 18 , wherein the clamp ring is expanded in alignment with a weld plane between the abutting ends.

20. The method of claim 19 , comprising aligning the pipe lengths and backing a weld between the pipe lengths with the same clamp ring.

21. The method of claim 18 , comprising pressing together the clamp ring elements during expansion of the clamp ring.

22. The method of claim 18 , comprising contracting the clamp ring for insertion or withdrawal of the clamp by effecting relative longitudinal retracting movement between the interdigitated groups of clamp ring elements.

23. The method of claim 22 , wherein at least one of the groups is driven to effect the retracting movement.

24. The method of claim 22 , wherein the clamp ring elements are held together during contraction of the clamp ring.

Assignees

• Acergy France SAS

Inventors

• Lacome Jacques
• Atin Cesar

Classifications

• B23K37/0531 Primary

  Internal pipe alignment clamps · CPC title

• B23K2101/10

  Pipe-lines · CPC title

• F16L13/02

  Welded joints · CPC title

• B23K37/06

  for positioning the molten material, e.g. confining it to a desired area · CPC title

• B23K9/0354

  the backing means being expandable · CPC title