This standard is issued under the fixed designation A 376/A 376M; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon ( ε) indicates an editorial change since the last revision or reapproval.

1.Scope

1.1This specification covers seamless austenitic steel pipe intended for high-temperature central-station service. Among the grades coved are five H grades and two nitrogen grdes (304n and 316N) that are specifically intended for high-temperature service.
1.2 Optional supplementary requirements (S1 through S10) are provided. These supplementary requirements specify additional tests that will be made only when stated in the order, together with the number of such tests required.
1.3 The values stated in either inch-pound units or SI units are to be regarded separately as standard. within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents;therefore, each system must be used independentiy of the other. Combining values from the two systems may result in nonconformance with the specification. The inch-pound units shall apply unless the "M" designation of this specification is specified in the order.

NOTE 1─The dimensionless designator NPS(nominal pipe size)has been substituted in this standard for such traditional terms as "nominal diameter," "size," and "nominal size.".