1.1 ,This specification2 covers 8 and 9 ,% nickel-alloy steel forged or rolled flanges, fittings, valves, and parts intended for use in welded pressure vessels for low-temperature service. The specification is applicable to forgings with maximum section thickness of 3 in. [75 mm] in the double normalized and tempered condition and 5 in. [125 mm] in the quenched and tempered condition. Forgings under this specification are intended for service at operating temperatures not lower than −,320 °,F [−,196 °,C] for Type I or −,275 °,F [−,170 °,C] for Type II or higher than 250 °,F [121 °,C].