This standard covers 3-in. through 64-in. (76 mm through 1,600 mm) ductile iron pipe, centrifugally cast, for water, with push-on joints or mechanical joints. Requirements for pipe covered by this standard are discussed in the text and are shown in tables and figures. This standard may be used for pipe with such other types of joints as may be agreed upon at the time of purchase. Section 1 discusses scope, purpose, and application. Sections 2 and 3 list references and definitions. Section 4 lists requirements, including: permeation; general requirements; coatings and linings; tolerances or permitted variations; weighing pipe; and, marking pipe. Section 5 discusses verification, including: inspection; test procedures, additional control tests by the manufacturer, foundry records, additional tests required by the purchaser, defective specimens and retests and rejection. The major revisions in this edition of ANSI/AWWA C151/A21.51-96 include the following: the format has been changed AWWA standard style; the acceptance clause (Sec. I.C) has been revised to approved wording; and, cement mortar lining (Sec. 4.3.2) is now standard, unless otherwise specified (Sec. III.A.6.b).