This standard describes bolted, sleeve-type couplings, reducing or transition couplings, and flanged coupling adapters used to join plain-end steel and ductile-iron pipe. They may be manufactured from carbon steel, stainless steel, ductile iron, or malleable iron, and are intended for use in systems conveying water. This standard describes nominal pipe sizes from 1/2 in. (13 mm) through 144 in. (3,600 mm). Major revisions made to the standard in this edition include the following: wording changes in Sec. 3, Sec. 4.2.4.1.1, and Sec. 4.3.1.