ASTM A213 T22 Seamless Ferritic and Austenitic Alloy-Steel Boiler,
Superheater, Heat-Exchanger Tubes.
ASTM A213 T22 Grades containing the letter H in their designation
have requirements different from those of similar grades not
containing the letter H.
These different requirements provide higher creep-rupture strength
than normally achievable in similar grades without these different
requirements. ASTM A213 T22 tubes shall be made by the seamless
process and shall be either hot finished or cold finished, as
specified. Grade TP347HFG shall be cold finished. Heat treatment
shall be done separately and in addition to heating for hot
forming. The ferritic alloy and ferritic stainless steels shall be
reheated. On the other hand, austenitic stainless steel tubes shall
be furnished in the heat-treated condition. Alternatively,
immediately after hot forming, while the temperature of the tubes
is not less than the minimum solution temperature, tubes may be
individually quenched in water or rapidly cooled by other means.
Tension test, hardness test, flattening test, and flaring test
shall be done to each tube. Also, each tube shall be subjected to
the nondestructive electric test or hydrostatic test.