his standard is issued under the fixed designation A 161; 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 minimum-wall-thickness, seamless, hot-finished and cold-finished, low-carbon and carbon-molybdenum steel still tubes, for use in carrying fluids at elevated temperatures and pressures in various types of heaters, in which the tubes may be subjected to furnace temperature higher than that of the contained fluid.
1.2 This specification covers tubes 2 to 9 in. (50.8 to 228.6 mm), inclusive in outside diameter and over 0.220 in. (5.59 mm) in minimum wall thickness.
1.3 Where butt welding is used to obtain lengths longer than single lengths normally produced in the mill, Specification A 422 shall cover the requirements for butt welds.
1.4 The values stated in inch-pound units are to be regarded as the standard. The values in parentheses are for information only.
