... superheater, heat exchanger, or condenser tubes.According to ASTM A249, subsequent to welding and prior to final heat treatment, the stainless steel pipes/ ... number of tubes as prescribed for the flattening test.1) Material of stainless steel: 201(approx 0.8-1.1% ... TIG welded, Plasma Arc Welded.3) Standards: ASTM A554, ASTM A249, ASTM A269, ASTM A270, ASTM A312,DIN 118504) Mark: Steel Seal and Label5 ...