DNV GL and Subsea Global Solutions LLC have completed an extensive joint research and development (R&D) programme that will allow permanent repairs to be carried out by underwater wet welding on certain areas of vessels.
The procedure will only be utilised in suitable locations, in accordance with the approvals given by DNV GL. Subsea Global Solutions’ global network of coded welder divers will be available to perform these permanent repairs on a case-by-case basis.
Over the last two and a half years, Subsea Global Solutions has welded in excess of 80 groove weld test plates underwater at depth in its training facilities in Miami, Florida, Long Beach, California, and Terneuzen, the Netherlands. The non-destructive and mechanical testing of the plates was performed at the DNV GL laboratory in Hamburg, Germany. All data collected was shared between SGS and DNV GL during this procedure development programme.
At the End of April 2014, test plates were welded in the training tank in Miami Florida, with a DNV GL welding engineer in attendance, and the non-destructive and destructive testing was again performed at the DNV GL laboratory in Hamburg.
Plate welding and testing was performed in accordance with AWS D3.6M:2010 Class A.
Non-destructive and destructive testing produced positive results, with all welded test plates exhibiting metallurgical properties equivalent to permanent weld repairs performed ‘top-side’ dry.
Adapted from press release by Callum O'Reilly
Read the article online at: https://www.lngindustry.com/lng-shipping/02092014/dnv-gl-approves-wet-welding-repairs-1317/