API STD 1104 pdf download.Welding of Pipelines and Related Facilities 1 General 1.1 SCOPE This standard covers the gas and arc welding of butt, fillet, and socket welds in carbon and low-alloy steel piping used in the compression, pumping, and transmission of crude petro- leum, petroleum products, fuel gases, carbon dioxide, nitro- gen and, where applicable, covers welding on distribution...