ARSD 20:54:23:02. Horizontal piping

Horizontal piping shall be supported at sufficiently close intervals to keep it in alignment and prevent sagging. Horizontal piping shall conform to the following standards: (1) Steel threaded pipe which is one-inch diameter or less shall be supported at eight-foot intervals, over one-inch diameter at ten-foot intervals; (2) Copper tubing shall be supported at approximately six-foot intervals for piping one and one-fourth inches and smaller and ten-foot intervals for piping one and one-half inches and larger; (3) Plastic pipe shall be supported at intervals not exceeding four feet.