This standard is issued under the fixed designation A 381; 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 ( ュ) indicates an editorial change since the last revision or reapproval.

1.Scope

1.1 This specification covers straight seam, double-sub-merged-arc-welded steel pipe (Note 1) suitable for high-pressure service, 16 in. (406 mm0 and lager in outside diameter, with wall thicknesses from 5/16 to 1 1/2 in. (7.9 to 38 mm). The pipe is intended for fabrication of fittings and accessories for compressor or pump-station piping. pipe ordered to this specification to this specification shall be suitable for bending, flanging (vastoning), corrugating, and similar operations.

NOTE 1ΑA comprehensive listing of standardized pipe dimensions is contained in ANSI B36.10.
NOTE 2ΑThe term "double weled" is commonly used in the gas and oil transmission industry, for which this pipe is primarily intended, to indicate welding wit at least two weld passes, of which one is on the outside of the pipe and one on the inside.
For some sizes of the pipe covered by this specification, it becomes expedient to use manual welding, in which case the provisions of the Note in 5.2 shall be followed.

1.2 Nine classes of pipe, based on minimum yield point requirements, are covered as indicated in Table 1.
1.3 The values stated in inch-pound units are to be regarded as the standard. The metric equivalents of inch-pound units may be approximate.
1.4 The following hazard caveat applies to the test methods portion, Sections 9 and 10, only. This standard does not purport to address all of the safety problems, 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.