1.1This specification covers malleable iron flanges, pipe fittings, and valve parts, including parts to be assembled for use in railroad, marine, and other heavy-duty service applications where fittings furnished in accordance with American National Standard for Malleable Iron Threaded Fittings, Classes 150 and 300 (ANSI B16.3) are not considered adequate.

1.2Service shall include up to 650 °F (345 °C).2

1.3The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.4This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.