[Code of Federal Regulations] [Title 46, Volume 2] [Revised as of October 1, 2004] From the U.S. Government Printing Office via GPO Access [CITE: 46CFR54.25-15] [Page 165] TITLE 46--SHIPPING CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PART 54_PRESSURE VESSELS--Table of Contents Subpart 54.25_Construction With Carbon, Alloy, and Heat Treated Steels Sec. 54.25-15 Low temperature operation--high alloy steels (modifies UHA-23(b) and UHA-51). (a) Toughness tests for the materials listed in UHA-51(a) of the ASME Code for service temperatures below -425 [deg]F., UHA-51(b)(1) through (5) for service temperatures below 0 [deg]F., and UHA-51(c) for all service temperatures, shall be performed in accordance with the requirements of subpart 54.05. These requirements are also applicable to nonpressure vessel type, low temperature tanks and associated secondary barriers, as defined in Sec. 38.05-4 in subchapter D (Tank Vessels) of this chapter. Such tests are required regardless of the vessel's design stress. Service temperature is defined in Sec. 54.25-10(a)(2). (b) Materials for pressure vessels with service temperatures below - 320 [deg]F. shall be of the stabilized or low carbon (less than 0.10 percent) austenitic stainless steel type, produced according to the applicable specifications of Table UHA-23 of the ASME Code. These materials and their weldments shall be tested for toughness according to the requirements of subpart 54.05 except that the Charpy V-notch testing acceptance criteria will be in accordance with UHT-6(a)(4) and (5) of the ASME Code.'' (c) Except as permitted by Sec. 54.05-30, the allowable stress values used in the design of low temperature pressure vessels may not exceed those given in Table UHA-23 of the ASME Code for temperatures of -20 [deg]F. to 100 [deg]F. [CGFR 68-82, 33 FR 18828, Dec. 18, 1968, as amended by CGD 73-133R, 39 FR 9178, Mar. 8, 1974; CGD 73-254, 40 FR 40164, Sept. 2, 1975]