ASTM A 688/A 688M - 03 Standard Specification for Welded Austenitic Stainless Steel Feedwater Heater Tubes

1. Scope*
1.1 This specification2 covers welded austenitic stainless
steel feedwater heater tubes including those bent, if specified,
into the form of U-tubes for application in tubular feed-water
heaters.
1.2 The tubing sizes covered shall be 5⁄8 to 1 in. [15.9 to
25.4 mm] inclusive outside diameter, and average or minimum
wall thicknesses of 0.028 in. [0.7 mm] and heavier.
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 shall
be used independently of the other. Combining values from the
two systems may result in nonconformance with the specification.