This 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. The sizes, shapes, and dimensions of the fittings shall conform to the requirements specified. The iron shall be produced under constant control of chemical composition and physical properties. Records of the chemical composition of the iron and of the physical properties of the test specimens shall be systematically made and maintained.

1.1 This 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.

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

1.3 The 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.

1.4 This 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.