Boskalis BVBA and W.Smit BV contracted Divewise Tec with the aim to undertake two (2) new Welding Procedure Specification (WPS) for its wet welding purposes. Divewise Tec in its turn subcontracted and entrusted Marex Subsea Welds Ltd to perform all the necessary preparatory and on-site works in order to develop the new two Welding Procedure Specifications (WPS). Marex Subsea Welds' role was to carry out weldability trials in accordance with AWS D3.6M:2017 Class A Welds in order to qualify procedures to enable welding of S355J2 on API 5L Grade X65 (or equivelant materials) and API 5L Grade X65 on API 5L Grade X70 (or equivelant materials). All welds were executed with the NAUTILUS electrode.

The on-site trials' duration lasted approximately ten (10) days and took place at the sea region of Piraeus Port. Marex had to provide apart from suitable premises and equipment acording to OGP rules, the appropriate materials, documentation (i.e. prerequisite documents for the trials, clarifications and proposals, dive project plan, risk assessment, welding method statement etc.) as well as the working team (engineers, coded welders, diving team, HSE) for the trials.

Mr. David J. Keats acted as third party; partner at WeldCraft-Pro (part of Speciality Enterprises).

Thoughout the duration of the welding trials, four (4) specimens both on butt and fillet weld were welded in PG (3G) and PJ (5F) fixed position and more than twenty (20) laboratory tests were conducted. Non-Destructive and Destructive Tests have been made by an independent laboratory, G.A.T.S. Ltd (NB#1935-GR).

The labotary's reports certify that Class A was achieved.