DNV DNVGL-RP-B204 [ Revised ]

This recommended practice specifies the technical requirements for welding subsea equipment. This includes requirements for quality assurance, welding procedure qualification, non-destructive testing and inspection, and welding and inspection personnel. The scope covers primary load bearing welds and welds exposed to hydrocarbon process fluids for the following pressure retaining equipment:

— subsea wellhead and tree equipment as per ISO 13628-4 or API Spec 17D

— manifolds as per ISO 13628-15 or API RP 17P

— flowline connectors and jumpers as per API RP 17R.

The following types of welds between forged or hot isostatic pressing (HIP) materials and pipe materials are included:

— girth welds in carbon steels (CS) and low alloy steels (LAS) with and without internal cladding

— corrosion-resistant overlay welding with alloy 625, i.e. cladding, load and non-load bearing

— girth welds of dissimilar materials, including LAS and Ni-based buttering

— girth welds in 22Cr and 25Cr duplex stainless steels.

Special requirements for fatigue sensitive welds are not included in this recommended practice. If required, fatigue assessment should be performed in accordance with DNVGL-RP-C203.