Case study: AWS D3.6 underwater welder qualification for P.S.S. Ltd.
Professional Subsea Service Limited (P.S.S. Ltd.) is a Cyprus-based contractor performing subsea technical, design and investigational work in the petrochemical, maritime and heavy-industry sectors, originally based in Ukraine before relocating to Nicosia. After winning a project in Turkmenistan, P.S.S. asked the Hyperbaric Welding Center to arrange the welder performance qualifications (WPQ) its divers needed to carry out the work.
The qualification scope
The project required P.S.S.’ welder-divers to hold welding certificates under the internationally recognised AWS (American Welding Society) code, for two depths: 3.5 metres and 21 metres. The qualification was carried out under AWS D3.6 Class B — the class intended for less critical underwater applications, with adjusted acceptance criteria compared to the more stringent Class O. The test scope covered a pipe-plate joint configuration in positions 2F and 4F at 3.5 metres, and position 4F at 21 metres.
Preparing and running the test
Ahead of the qualification test, a training was organised to give the welder-divers the best chance of a good result. To make efficient use of time, the dive pit and the (indoor) dive pool were used simultaneously — a dual set-up that substantially increased throughput. Taking decompression schedules and nitrox use into account, the full scope was completed within five days.
Outcome
All qualifications were carried out successfully, expanding P.S.S. Ltd.’s certified underwater welding capacity for the Turkmenistan project.
What this shows about qualification at depth
AWS D3.6M remains one of the two standards we qualify underwater welders under today, alongside EN ISO 15618-1 — see the standards, explained for how the two compare. As in this project, water depth is treated as an essential qualification variable: our 21-metre dive basin in Enkhuizen has a movable floor that sets the test depth to the centimetre, so a qualification can be arranged for the specific depth range a project requires.
Related reading: what a DNV underwater welder qualification test looks like, step by step, or qualifying a dive crew as an employer or contractor.