适用于具有对接焊缝的焊接钢管和管件，其公称尺寸为100 mm至1000 mm，主要用于输送水、污水和中压气体。指定常用配件的标准外径和要求。还规定了外部保护涂层和内部衬里。

Applies to welded steel pipes and fittings with butt welded seams in sizes of 100 mm to 1000 mm nominal pipe sizes intended primarily for the conveyance of water, sewage, and medium pressure gas. Specifies standard outside diameters and requirements for commonly used fittings. Also specifies external protective coatings and internal linings.