7.1.1 All welding processes shall be protected from adverse weather conditions that may affect weld quality. When welding is performed outdoors in adverse weather conditions, temporary shelters shall be erected to completely enclose the work area. In addition, for gas shielded processes windshields shall always be erected to prevent loss of shielding gas 7.2 Acceptable Welding Processes The following welding processes are acceptable subject to the restrictions noted. The use of welding processes other than those listed shall require prior Owner review and approval. For these cases, Owner reserves the right to impose additional requirements or testing to those required by the code.
7.2.1 Shielded Metal Arc Welding (SMAW)
7.2.1.1 SMAW may be used to weld the root pass in single-welded joints without backing in carbon steel lines provided:
• The electrode is specifically formulated for this purpose (i.e. having a rutile or cellulosic coating) • The lines are not in a corrosive environment (e.g. H2S, water, caustic, etc.).
• P-1 Grp-2 material shall be pre-heated to 300°F (150°C) and maintained until subsequent passes commence with a low hydrogen consumable or welding process.