This specification covers welded tube of specific copper and various copper alloys of a limited range of diameters, for use in surface condensers, evaporators, heat exchangers, and general engineering applications. The product shall be manufactured by forming the material into a tubular shape on a suitable forming mill. Welding of tube shall be accomplished by forge-welding, fusion-welding, or full finishing that produces a forge weld leaving no crevice in the weld seam visible to the unaided eye. The tube shall conform to tensile strength and yield strength requirements, and shall be subject to expansion, flattening, and reverse bend tests. Mercurous nitrate or ammonia vapor tests shall be required only for selected UNS Numbers of Copper Alloys. Each tube shall be subjected to eddy-current, hydrostatic, and pneumatic tests.