{"operation":"document","citation":"05-0199","title":"Mr. Ed Mansell — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2005-11-03","effective_on":null,"summary":"05-0199 concerning 178.345.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-05-0199.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-05-0199.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-05-0199","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2005/050199.pdf","body":"<<<PAGE 1>>>\n\nof Transportation\nU.S. Department\n400 Seventh Street, S.W.\nWashington, D.C. 20590\nHazardous Materials Safety\nPipeline and\nNOV - 3 2005\nAdministration\nMr. Ed Mansell\nRef. No.: 05-0199\nP.O. Box 310\n4825 E. Kearney\nSpringfield, OH 65801\nDear Mr. Mansell:\nThis is in response to your August 18, 2005 letter requesting clarification of the\nHazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to structural\nintegrity of cargo tanks. Specifically, you ask whether the following allowable: stress for\nstress concentrations are acceptable under the structural requirements for cargo tanks\nunder § 178.345-3 of the HMR:\nPrimary Stress Allowable:\n1.5xSa*E, where Sa is the 1998 ASME\nCode allowable stress, and E is the joint\nefficiency; and\nPrimary + Secondary Stress Allowable:\n3xSa*E, where Sa is the 1998 ASME Code\nallowable stress, and E is the joint:\nefficiency.\nSection 178.345-3(b) specifically requires cargo tank designers to use Appendix G of the\nAmerican Society of Mechanical Engineers (ASME) Code when considering stress\nconcentrations which occur at pads, cradles, or other supports. Provided the stress\nconcentrations occur at pads, cradles, or other supports, Appendix G of the ASME Code\nis mandatory when considering designing DOT specification cargo tanks.\nI hope this information is helpful.\nSincerely,\nL'un\n'Susan Gorsky\nActing Director\nOffice of Hazardous Materials Standards\n198-345-3\n050199\n\n<<<PAGE 2>>>\n\nFrom: Ed Mansell\n4825E. Kearney\nP.O. Box 310\nRef.:\nThursday, August 18, 2005\n178345-3STR\nSpringfield, MO 65801\nTo:\nOffice of Hazardous Materials\nFoster\nResearch and Special Programs Administration\n400 7\" Street SW.,\nU.S. Department of Transportation\nWashington, DC 20590-001\n5178.345-3\nAttn:\nDHM-10\nCaryo Tanks\nSec. 178.345-3 Structural integrity.\n05-0199\n(a)\nGeneral requirements and acceptance criteria.\n(1)\nallowable stress value prescribed in Section VIII of the ASME Code (IBR, see Sec. 171.7 of this subchapter), or\nThe maximum calculated design stress at any point in the cargo tank wall may not exceed the maximum\n25 percent of the tensile strength of the material used at design conditions.\n(b)\naccordance with Section VIII of the ASME Code. The cargo tank design must include calculation of stresses\nASME Code design and construction. The static design and construction of each cargo tank must be in\ngenerated by the MAWP, the weight of the lading, the weight of structures supported by the cargo tank wall and\nthe effect of temperature gradients resulting from lading and ambient temperature extremes. When dissimilar\nmaterials are used, their thermal coefficients must be used in the calculation of thermal stresses.\n(1) Stress concentrations in tension, bending and torsion which occur at pads, cradles, or other supports must\nbe considered in accordance with appendix G in Section VIII of the ASME Code.\n(2) Longitudinal compressive buckling stress for ASME certified vessels must be calculated using paragraph\nUG-23(b) in Section VIII of the ASME Code. For cargo tanks not required to be certified in accordance\nwith the ASME Code, compressive buckling\nHowever, paragraph (b)(1) makes an exception for stress concentrations in tension, bending and torsion, which occur at\nParagraph (a) (1) states that the allowable stress value shall be in accordance with Section VIII of the ASME Code.\npads, cradles, or other supports.\nTherefore, based on Appendix G which references WRC-107 and WRC-297 bulletins, the allowable stress for stress\nconcentrations would be:\nPrimary Stress Allowable:\nPrimary + Bending Stress Allowable:\n3xSa, where Sa is the ASME allowable, and E is the joint efficiency\n1.5xSa*E, where Sa is the ASME allowable, and E the joint efficiency\nQuestion:\nIs the interpretation as stated above correct?\nSincerely,\nEd Manselll","truncated":false,"body_characters":3802}