ASME PVHO-1–2007 pdf download.Safety Standard for Pressure Vessels for Human Occupancy.
1-6 MATERIALS All PVHO materials shall meet the requirements of this Standard. Pressure vessel metallic material shall meet the speci- fied Division of Section VIII of the Code. Nonstandard materials shall be qualified for use as defined in Non- mandatory Appendix D. The following materials shall not be used for pressure parts: SA-36, SA-283, SA-515, and cast and ductile iron. Ferrous materials for PVHOs shall also comply with the following requirements: (a) Except as provided for in paras. (b), (c), (d), or (e) below, drop-weighttests inaccordance withASTM E 208 shall be made on all wrought and cast ferrous materials. For plates, one drop-weight test (two specimens) shall be made for each plate in the as-heat-treated condition. For product forms other than plate, one drop-weight test (two specimens) shall be made for each heat in any one treatment lot. The sampling procedure for each form of material shall comply with the requirements of the specifications listed in the Code in either Table UG-84.3 or Table AM-204.3, as applicable. The test shall be con- ducted ata temperature 30°F (17°C) lower than the mini- mum temperature for seamless and postweld heat- treated vessels, and 50°F (28°C) lower for as-welded vessels. The two specimens shall both exhibit no break performance. (b) When, due to the material thickness or configura- tion, drop-weight specimens cannot be obtained, Charpy V-notch tests shall be conducted. The Charpy V-notch test of each form of material shall comply with the requirements of the specifications listed in either Table UG-84.3 or Table AM-203.3, as applicable, in all respects, except the test temperature shall not be higher than that specified in para. (a) above. (c) As an alternative to the requirements of para. (a) above, those materials listed in Table A1.15 of Section II, Part A, SA-20, of the Code may be accepted on the basis ofCharpyV-notchtesting.
(1) normalized, fully killed, and made in accor- dance with fine grain practice (2) fully killed, made in accordance with fine grain practice with a grain size of 5 or finer, and an operating temperature of 50°F (10°C) or higher (e) The additional toughness tests of paras. (a), (b), and (c) above may be waived for the 300 series stainless steels. (f) When the material has a specified minimum yield strength exceeding 60 ksi (414 MPa), weld metal and heat-affected zone impact properties for weld procedure qualifications and weld production tests shall also meet the requirements ofthe specified Division ofSection VIII of the Code at a test temperature 30°F (17°C) lower than the design temperature, regardless of the value of the design minimum temperature. PVHOs constructed of ferrous materials that are exposed to the corrosive effects of marine environments shall have provisions made for the desired life by a suitable increase in the thickness of the material over thatrequired by the design procedures, or by using some other suitable method of protection. 1-7 DESIGN AND FABRICATION REQUIREMENTS 1-7.1 Joint Design The design and fabrication shall be in accordance with the specified Division ofSection VIII ofthe Code and the following requirements common to all PVHOs, unless otherwise permitted within this Standard: (a) All joints of Categories A, B, and C shall be Type No. 1 of Table UW-12 for Section VIII, Division 1 vessels or shall comply with AF-221 for Section VIII, Division 2 vessels. (b) All joints of Category D shall be full penetration welds extending through the entire thickness of the ves- sel or nozzle wall. Backing strips shall be removed. (c) Intermediate heads may be designed in accor- dance with Fig. UW-13.1(f) for Section VIII, Division 1 vessels only when the following conditions are met