1.1 This specification2 covers austenitic ductile iron, Type D-2M, Classes 1 and 2, for compressors, expanders, pumps, valves, and other pressure-containing parts intended primarily for low-temperature service.

1.2 These grades of austenitic ductile iron are characterized by having their graphite substantially in a spheroidal form and free of flake graphite. They are essentially free of carbides and contain sufficient alloy content to produce a stable austenitic matrix down to −423°F [−252°C] (liquid hydrogen).

1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

1.4 The following precautionary caveat pertains only to the test methods portion, Section 11, of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.