The Norwegian Oil Industry Association (OLF) and Federation of Norwegian Manufacturing Industries (TBL). Rev. 4, July 2004. 20p. This NORSOK standard covers additional and optional technical requirements to ASME B31.3 for welding and weld inspection of piping systems, selected according to NORSOK L-001, and applies to all piping fabrication including prefabrication, module assembly, package or skid mounted units, site and field
installation.