{"operation":"document","citation":"22-0011","title":"Betts Industries, Inc. — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2022-07-28","effective_on":null,"summary":"22-0011 response to Betts Industries, Inc. concerning 178.345.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-22-0011.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-22-0011.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-22-0011","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/76676/220011.pdf","body":"<<<PAGE 1>>>\n\n1200 New Jersey Avenue, SE\nWashington, DC 20590\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\nJuly 28, 2022\nMr. David J. Adams\nDirector of Design Engineering\nBetts Industries, Inc.\n1800 Pennsylvania Ave W.\nWarren, PA 16365\nReference No. 22-0011\nDear Mr. Adams:\nThis letter is in response to your February 23, 2022, email requesting clarification of the\nHazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the venting\ncapacity of pressure relief systems for cargo tanks, specified in § 178.345-10(e). You state that\n“Table 1 - Minimum Emergency Vent Capacity” in paragraph (e) includes a note which allows\nfor interpolation of the values on the table for intermediate sizes of cargo tanks, specifically\nexposed area in square feet. However, you note that it is not stated whether one can extrapolate\nthe data on the table for cargo tanks larger than 1,000 square feet. You have provided an\nadditional table showing data that you have interpolated and extrapolated from Table 1 in\n§ 178.345-10(e). Lastly, you state that you are not aware of any regulation which limits the size\nof a cargo tank to less than 1,000 square feet of exposed area.\nWe have paraphrased and answered your questions as follows:\nQ1. You ask whether there is any regulation that limits the size of a cargo tank to being no\ngreater than 1,000 square feet of exposed area.\nA1. Although the HMR do not limit the size of a cargo tank, the Federal Highway\nAdministration (FHWA) regulates commercial vehicle weight and size requirements, in\nconjunction with state enforcement agencies. More information on the federal\ncommercial vehicle size and weight program can be found on FHWA’s website at the\nfollowing web address: https://ops.fhwa.dot.gov/freight/sw/overview/index.htm.\nQ2. You ask what venting capacity is required if the cargo tank has an exposed area of greater\nthan 1,000 square feet.\n\n<<<PAGE 2>>>\n\nA2. As you have stated in your email, the table for minimum emergency vent capacity in\n§ 178.345-10(e) does not have a corresponding value for cargo tanks with an exposed\narea of greater than 1,000 square feet. It is the opinion of this Office that for cargo tanks\nwith greater than 1,000 square feet of exposed area, extrapolation would be acceptable to\ndetermine the value of the cubic feet free air per hour. However, the extrapolation\ncalculation should be verified by the Design Certifying Engineer responsible for\ndetermining compliance of the cargo tank design.\nQ3. You ask whether extrapolation of the data from Table 1 in § 178.345-10(e) is permitted.\nA3. Please see answer A2.\nI hope this information is helpful. Please contact us if we can be of further assistance.\nSincerely,\nT. Glenn Foster\nChief, Regulatory Review and Reinvention Branch\nStandards and Rulemaking Division\n\n<<<PAGE 3>>>\n\nLarson\n22-0011\nFrom: Raynor, T\"Mia (PHMSA)\nTo: Hazmat Interps\nSubject: FW: Request for Interpretation 49CFR§178.345-10\nDate: Wednesday, February 23, 2022 1:49:20 PM\nAttachments: image003.png\nGood Afternoon,\nWould someone be able to assist the user below?\nThanks,\nT’Mia Raynor\nWebmaster, Office of the PHMSA CIO\nUS Department of Transportation\nPipeline and Hazardous Materials Safety Administration\n1200 New Jersey Ave. SE, Washington, D.C., 20590\nOffice: 202.366.9818 ◊ Mobile: 202.580.9447\nPHMSA Home | LinkedIn | Twitter | HAZMAT | OPS\nFrom: David J. Adams <dadams@bettsind.com>\nSent: Wednesday, February 23, 2022 12:54 PM\nTo: PHMSA Website Manager <PHMSAWebsiteManager@dot.gov>\nSubject: Request for Interpretation 49CFR§178.345-10\nCAUTION: This email originated from outside of the Department of Transportation (DOT). Do not click on links or open\nattachments unless you recognize the sender and know the content is safe.\nTo Whom It May Concern,\nI would like to request a regulation interpretation or clarification.\nCurrent regulation reads:\n49 CFR 178.345 10(e) Venting capacity of pressure relief systems. The pressure relief system (primary\nand secondary, including piping) must have sufficient venting capacity to limit the cargo tank internal\npressure to not more than the cargo tank test pressure. The total venting capacity, rated at not more\nthan the cargo tank test pressure, must be at least that specified in table I, except as provided in §\n178.348-4.\nTable I - Minimum Emergency Vent Capacity\n[In cubic feet free air/hour at 60 °F and 1 atm.]\nExposed area in square feet Cubic feet free air per hour\n20 15,800\n30 23,700\n40 31,600\n50 39,500\n\n<<<PAGE 4>>>\n\n60 47,400\n70 55,300\n80 63,300\n90 71,200\n100 79,100\n120 94,900\n140 110,700\n160 126,500\n180 142,300\n200 158,100\n225 191,300\n250 203,100\n275 214,300\n300 225,100\n350 245,700\n400 265,000\n450 283,200\n500 300,600\n550 317,300\n600 333,300\n650 348,800\n700 363,700\n750 378,200\n800 392,200\n850 405,900\n900 419,300\n950 432,300\n1,000 445,000\nThis table includes note 1 which allows for interpolation for intermediate sizes but it does not mention if\nextrapolation is permitted for larger size cargo tanks. I am not aware of any regulation which limits the size of a\ncargo tank to under 1,000 square feet of exposed area.\nThe specific questions are:\n1. Is there any regulation limiting the size of a cargo tank (specially a specification DOT406) to no greater\nthan 1,000 square feet of exposed area?\n2. 3. What venting capacity is required if the cargo tank has exposed area greater than 1,000 square feet?\nIs extrapolation of Table 1 permitted? (An example of extrapolated data is provided in Appendix A.)\nNote 1: Interpolate for intermediate sizes.\nAppendix A – Example of extrapolated capacity curve based off Table 1 of 49 CFR 178.345 10.\n\n<<<PAGE 5>>>\n\nExposed\nArea\n(sq. ft.)\nReq. Vent\nCapacity\n(scfh)\nExposed\nArea\n(sq. ft.)\nReq. Vent\nCapacity\n(scfh)\n20 15,800 450 283,200 40 31,600 475 291,900 80 63,300 500 300,600 100 79,100 525 308,950 120 94,900 550 317,300 140 110,700 575 325,300 160 126,500 600 333,300 180 142,300 625 341,050 200 158,100 650 348,800 225 191,300 675 356,250 250 203,100 700 363,700 275 214,300 725 370,950 300 225,100 750 378,200 325 235,400 775 385,200 350 245,700 800 392,200 375 255,350 825 399,050 400 265,000 850 405,900 425 274,100 875 412,600 Thank you for your time and consideration.\nExposed\nArea\n(sq. ft.)\nReq. Vent\nCapacity\n(scfh)\n900 419,300\n925 425,800\n950 432,300\n975 438,650\n1000 445,000\nExposed Area Extrap. Cap.\n1,025 451,275\n1,050 457,550\n1,075 463,700\n1,100 469,850\n1,125 475,900\n1,150 481,950\n1,175 487,900\n1,200 493,850\n1,225 499,725\n1,250 505,600\n1,275 511,375\n1,300 517,150\n\n<<<PAGE 6>>>\n\nBest regards,\nDavid J. Adams\nDirector of Design Engineering\ndadams@bettsind.com\nP 814-723-1250 Ex. 136 | F 814-723-5513\nBetts Industries, Inc.\n1800 Pennsylvania Ave W., Warren, PA 16365\nconfidential information. Unless stated to the contrary, any opinions or comments are personal to the writer and do not represent the\n**** Betts Industries, Inc. Email Notification **** This e-mail is only intended for the person(s) to whom it is addressed and may contain\nofficial view of the company. If you have received this e-mail in error, please notify us immediately by reply e-mail and then delete this\nmessage from your system. Please do not copy it or use it for any purposes, or disclose its contents to any other person. Thank you for your","truncated":false,"body_characters":7293}