Wire Arc Additive Manufacturing for Subsea Components – The First of a Kind 3D Printed Subsea Flange

Abstract

Additive manufacturing is gaining increasing interest as an alternative manufacturing process to produce conventional or engineered materials for pipelines. In this context, during 2021 Saipem launched an R&D initiative to explore the possibility to deploy Wire Arc Additive Manufacturing Process (WAAM) to produce typical components of a subsea pipeline system. The main objective is to demonstrate that WAAM is suitable to produce pieces having similar properties than the ones manufactured via traditional methods and that they could be used for typical offshore components. As a first trial, Saipem decided to start with the production and testing of a subsea flange and the scope was assigned to Vallourec S.A. Scope of the present paper is to share the main challenges faced during the activity and the main outcomes of it. The selected grade was an ASTM A694 F65 equivalent grade that is considered a representative case for several offshore scenarios and the produced flange was a WELDING NECK 11" API 6A (10.000 psi) which represented in terms of WAAM technology the largest part ever printed by Vallourec. Manufacturing, inspection, and testing has been carried out following the requirements of DNVGL-ST-B203 for AMC 3 category. After the printing of a pre-build piece to verify the main properties and to confirm that the parameters were suitable for the production, the full-scale component was then printed as well and destructive testing has been done in critical areas of the piece after NDT inspection.