API RP 934-A

Description

This recommended practice (RP) covers materials and fabrication requirements for new 2¼Cr and 3Cr steel heavy wall pressure vessels for high-temperature, high-pressure hydrogen service. For this RP, “heavy wall” is defined as a shell thickness of 4 in. (100 mm) or greater, and high-temperature is considered to be operating temperatures of 650 °F (345 °C) and above. This RP applies to vessels that are designed, fabricated, certified, and documented in accordance with ASME Section VIII, Division 2, including Paragraph 3.4, Supplemental Requirements for Cr-Mo Steels, and ASME Code Case 2151, as applicable. Materials covered by this RP are conventional steels including standard 2¼Cr-1Mo and 3Cr-1Mo steels, and advanced steels which include 2¼Cr-1Mo-¼V, 3Cr-1Mo-¼V-Ti-B, and 3Cr-1Mo-¼V-Nb-Ca steels. This document may be used as a reference document for the fabrication of vessels made of enhanced steels (steels with mechanical properties increased by special heat treatments such as ASME SA-5