US 11,684,991 B2
Methods and apparatus for repairing a tubular structure
Frederik Geert Niemeyer, Grimsby (CA)
Assigned to CANDU ENERGY INC., Mississauga (CA)
Appl. No. 16/765,736
Filed by CANDU ENERGY INC., Mississauga (CA)
PCT Filed Nov. 28, 2018, PCT No. PCT/CA2018/051513
§ 371(c)(1), (2) Date May 20, 2020,
PCT Pub. No. WO2019/104427, PCT Pub. Date Jun. 6, 2019.
Claims priority of provisional application 62/591,755, filed on Nov. 28, 2017.
Prior Publication US 2020/0290145 A1, Sep. 17, 2020
Int. Cl. B23K 9/173 (2006.01); B23K 9/04 (2006.01); B23K 103/04 (2006.01); B23K 101/06 (2006.01); B23K 9/12 (2006.01); B23K 9/32 (2006.01); B23K 37/02 (2006.01)
CPC B23K 9/173 (2013.01) [B23K 9/04 (2013.01); B23K 9/124 (2013.01); B23K 9/326 (2013.01); B23K 37/0276 (2013.01); B23K 2101/06 (2018.08); B23K 2103/05 (2018.08)] 15 Claims
OG exemplary drawing
 
1. A method of in-situ repairing a defect in a tubular structure, comprising:
extending a locking actuator to contact said tubular structure and anchor said locking actuator to fix the position of an end effector with respect to the tubular structure, said end effector comprising a wire electrode;
forming a droplet of weld material on the wire electrode;
oscillating the wire electrode to detach the droplet of weld material as the electrode retracts from the tubular structure; and
depositing a protective weld layer over the defect by sequentially depositing each droplet of weld material detached from the oscillating wire electrode atop a weld pool on said structure,
wherein said protective weld layer bonds to said structure surrounding said defect to structurally join non-defective metal on both sides of said defect and covers said defect and overlaps to said structure surrounding said defect by a defined margin,
wherein sequentially depositing weld droplets comprises selectively moving a wire electrode of a weld torch between a retracted position in which the weld droplet is formed, and an advanced position in which the weld droplet is deposited on the structure, and
wherein sequentially depositing weld droplets comprises depositing each droplet of weld material adjacent a previously deposited droplet to form the protective weld layer and moving the wire electrode in a path to deposit weld material over the entirety of said defect and a portion of said structure surrounding said defect.