1.1 This specification covers minimum-wall-thickness, electric-resistance-welded, carbon steel tubes including thosebent, ifspecified, into theformofU-tubes forapplica-tion in tubular feedwater heaters.
1.2 The tubing sizes covered shall be 1 ⁄ 8 to 1 1 ⁄ 4 in.[15.9 to 31.8 mm] outside diameter, inclusive, and wall thicknesses equal to or greater than 0.045 in. [1.1 mm].
