A
249 / SA 249
Standard
Specification for Welded Austenitic Steel Boiler,
Superheater, Heat-Exchanger, and Condenser Tubes
Overview
1.1 This specification covers nominal-wall-thickness
welded tubes made from the austenitic steels listed
in Table 1, with various grades intended for such
use as boiler, superheater, heat exchanger, or condenser
tubes.
1.2 Grades TP304H, TP309H, TP309HCb,
TP310H, TO310HCb, TP316H, TP321H, TP347H, and TP348H
are modifications of Grades TP304, TP309S, TP309Cb,
TP310S, TP310Cb, TP316, TP321, TP347, and TP348,
and are intended for high-temperature service such
as for superheaters and reheaters.
1.3 The tubing sizes and thicknesses
usually furnished to this specification are 1/8
in. [3.2 mm] in inside diameter to 5 in. [127 mm]
in outside diameter and 0.015 to 0.320 in. [0.4
to 8.1 mm], inclusive, in wall thickness. Tubing
having other dimensions may be furnished, provided
such tubes comply with all other requirements of
this specification.
1.4 Mechanical property requirements
do not apply to tubing smaller than 1/8 in. [3.2
mm] in inside diameter or 0.015 in. [0.4 mm] in
thickness.
1.5 Optional supplementary requirements
are provided and, when one or more of these are
desired, each shall be so stated in the order.
1.6 The values stated in either
inch-pound units or SI units are to be regarded
separately as standard. (A combination of 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.
Technical Information
Specifications 
