Covers design, manufacture, inspection, testing, marking, handling, and storage of pipes with butt welded seams in outside diameters of 114.3 mm and over, and primarily intended for the conveyance of water and town gas under pressure. Maximum hoop stress is specified, and dimensions are given in terms of outside diameter and nominal size (a rough indication of inside diameter). Provision is made for pipe joints to be welded or flexible. Welding requirements cover the process used, operators, equipment, edge preparation, plate set-up, welds, welding procedure, and repair of defects. Bends, tensile, impact and hydrostatic pressure test are specified.