{"operation":"document","citation":"22-0067","title":"Kidde Aerospace and Defense — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2023-04-20","effective_on":null,"summary":"22-0067 response to Kidde Aerospace and Defense concerning 178.35, 178.47, 178.53, 180.209.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-22-0067.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-22-0067.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-22-0067","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/77491/220067.pdf","body":"<<<PAGE 1>>>\n\nApril 20, 2023\nMark Fazzio\nChief Engineer\nKidde Aerospace and Defense\n4200 Airport Dr.\nWilson, NC 27896\nReference No. 22-0067\nDear Mr. Fazzio:\nThis letter is in response to your June 22, 2022, email requesting clarification of the Hazardous\nMaterials Regulations (HMR; 49 CFR Parts 171-180) applicable to service and test pressure\nrequirements for DOT-4D, DOT-4DA, and DOT-4DS pressure vessel specifications.\nSpecifically, you provide a scenario of a DOT-4D pressure vessel made from 4130 steel with a\nservice pressure of 500 psi.\nBased on the scenario provided we have paraphrased and answered your questions as follows:\nQ1. You ask whether the HMR allows for the actual test pressure to exceed two times the\nservice pressure, as prescribed for a DOT-4D (see § 178.53(e)), DOT-4DA (see\n§ 178.58(f)), and DOT-4DS (see § 178.47(f)), respectively.\nA1. The answer is yes. However, the actual test pressure must not exceed 110% of the\nminimum test pressure, with an allowance of +1%, per CGA C-1 Pamphlet (2016),\nSection 5.2.1. During the hydrostatic test, each specification requires a minimum test\npressure of at least two (2) times the service pressure. It is discouraged to have the actual\ntest pressure exceed the guidance provided in the CGA C-1 Pamphlet as it may cause an\nunsafe condition.\nQ2. You ask whether the HMR allows for the wall stress calculation to be based on two times\nthe service pressure, including in cases where the test pressure exceeds two times service\npressure.\nA2. The answer is yes. Wall stress calculations must be based on the minimum test\npressure—which is defined as two (2) times the service pressure. This applies for DOT-\n4D, DOT-4DA, and DOT-4DS specifications.\nQ3. You ask whether the wall stress calculated at a test pressure which is greater than two\ntimes the service pressure may exceed the stress threshold, per §§ 178.47(f), 178.53(e), or\n178.58(f), provided that the calculated stress at two times service pressure does not\nexceed the stated limits.\nA3. Wall stress must be calculated using a test pressure of two (2) times the service pressure\nfor the DOT-4D, DOT-4DA, and DOT-4DS specifications.\nCONCUR:\nROUTING\nPHH-11\nINITIALS\nECR\nDATE\n7/21/22\nROUTING\nPHH-11\nINITIALS\nDDK\nDATE\n07/22/22\nROUTING\nPHH-22\nINITIALS\nKWAC\nDATE\n2/2/23\nROUTING\nPHH-22\nINITIALS\nCWF\nDATE\n2/3/23\nROUTING\nPHH-10\nINITIALS\nMBN w/\nedits\nDATE\n2/10/23\nROUTING\nPHH-40\nINITIALS\nKM\nDATE\n2/28/23\nROUTING\nPHC-10\nINITIALS\nAG\nBSB\nw/edits\nDATE\n3/27/202\n3\n3/30/23\n\n<<<PAGE 2>>>\n\nQ4. Prior to performing the hydrostatic test, you ask whether the test can be performed at\n90% of actual test pressure, including cases where the test pressure exceeds two times the\nservice pressure.\nA4. The answer is yes. For both the DOT-4DA and DOT-4DS specifications, the test can be\nperformed at 90% of the minimum test pressure which is defined as two (2) times the\nservice pressure.\nFor the DOT-4D specification, the test can be performed at 90% of the minimum test\npressure which is two (2) times the service pressure (see § 178.53(h)(3)(ii)). For the lot\ntest in § 178.53(h)(1)(iii), the test can be performed at 90% of the test pressure equal to\nthree (3) times the service pressure (which exceeds two (2) times service pressure).\nHowever, if opting to use the latter performance standard, the remainder of the lot must\nbe tested using a proof pressure method. Section 5.7 of the CGA C-1 Pamphlet provides\nfurther guidance on performing the 90% system check.\nQ5. You ask whether the test pressure may be marked in addition to the markings required in\n§ 178.35.\nA5. The answer is yes. As specified in § 178.35(f)(6), other markings are authorized,\nprovided they are made in low stress areas, other than the side wall, and are not of a size\nand depth that will create harmful stress concentrations. Such marks may not conflict\nwith any DOT required markings. However, a test pressure marking that reflects a\npressure higher than the minimum test pressure of two (2) times service pressure is\ndiscouraged as it may create confusion and an unsafe condition—especially when the\ncylinder is due for requalification in accordance with § 180.209.\nI hope this information is helpful. Please contact us if we can be of further assistance.\nSincerely,\nDirk Der Kinderen\nChief, Standards Development Branch\nStandards and Rulemaking Division\n\n<<<PAGE 3>>>\n\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\n1200 New Jersey Avenue, SE\nWashington, DC 20590\nApril 20, 2023\nMark Fazzio\nChief Engineer\nKidde Aerospace and Defense\n4200 Airport Dr.\nWilson, NC 27896\nReference No. 22-0067\nDear Mr. Fazzio:\nThis letter is in response to your June 22, 2022, email requesting clarification of the Hazardous\nMaterials Regulations (HMR; 49 CFR Parts 171-180) applicable to service and test pressure\nrequirements for DOT-4D, DOT-4DA, and DOT-4DS pressure vessel specifications.\nSpecifically, you provide a scenario of a DOT-4D pressure vessel made from 4130 steel with a\nservice pressure of 500 psi.\nBased on the scenario provided we have paraphrased and answered your questions as follows:\nQ1. You ask whether the HMR allows for the actual test pressure to exceed two times the\nservice pressure, as prescribed for a DOT-4D (see § 178.53(e)), DOT-4DA (see\n§ 178.58(f)), and DOT-4DS (see § 178.47(f)), respectively.\nA1. The answer is yes. However, the actual test pressure must not exceed 110% of the\nminimum test pressure, with an allowance of +1%, per CGA C-1 Pamphlet (2016),\nSection 5.2.1. During the hydrostatic test, each specification requires a minimum test\npressure of at least two (2) times the service pressure. It is discouraged to have the actual\ntest pressure exceed the guidance provided in the CGA C-1 Pamphlet as it may cause an\nunsafe condition.\nQ2. You ask whether the HMR allows for the wall stress calculation to be based on two times\nthe service pressure, including in cases where the test pressure exceeds two times service\npressure.\nA2. The answer is yes. Wall stress calculations must be based on the minimum test\npressure—which is defined as two (2) times the service pressure. This applies for DOT-\n4D, DOT-4DA, and DOT-4DS specifications.\nQ3. You ask whether the wall stress calculated at a test pressure which is greater than two\ntimes the service pressure may exceed the stress threshold, per §§ 178.47(f), 178.53(e), or\n\n<<<PAGE 4>>>\n\n178.58(f), provided that the calculated stress at two times service pressure does not\nexceed the stated limits.\nA3. Wall stress must be calculated using a test pressure of two (2) times the service pressure\nfor the DOT-4D, DOT-4DA, and DOT-4DS specifications.\nQ4. Prior to performing the hydrostatic test, you ask whether the test can be performed at\n90% of actual test pressure, including cases where the test pressure exceeds two times the\nservice pressure.\nA4. The answer is yes. For both the DOT-4DA and DOT-4DS specifications, the test can be\nperformed at 90% of the minimum test pressure which is defined as two (2) times the\nservice pressure.\nFor the DOT-4D specification, the test can be performed at 90% of the minimum test\npressure which is two (2) times the service pressure (see § 178.53(h)(3)(ii)). For the lot\ntest in § 178.53(h)(1)(iii), the test can be performed at 90% of the test pressure equal to\nthree (3) times the service pressure (which exceeds two (2) times service pressure).\nHowever, if opting to use the latter performance standard, the remainder of the lot must\nbe tested using a proof pressure method. Section 5.7 of the CGA C-1 Pamphlet provides\nfurther guidance on performing the 90% system check.\nQ5. You ask whether the test pressure may be marked in addition to the markings required in\n§ 178.35.\nA5. The answer is yes. As specified in § 178.35(f)(6), other markings are authorized,\nprovided they are made in low stress areas, other than the side wall, and are not of a size\nand depth that will create harmful stress concentrations. Such marks may not conflict\nwith any DOT required markings. However, a test pressure marking that reflects a\npressure higher than the minimum test pressure of two (2) times service pressure is\ndiscouraged as it may create confusion and an unsafe condition—especially when the\ncylinder is due for requalification in accordance with § 180.209.\nI hope this information is helpful. Please contact us if we can be of further assistance.\nSincerely,\nDirk Der Kinderen\nChief, Standards Development Branch\nStandards and Rulemaking Division\n\n<<<PAGE 5>>>\n\nCardez\n22-0067\nFrom: INFOCNTR (PHMSA)\nTo: Subject: Date: Dodd, Alice (PHMSA); Hazmat Interps\nFW: Interpretation of 49 CFR 178.47, 178.53 and 178.58\nThursday, June 30, 2022 2:14:18 PM\nAttachments: 178-4D-4DS-4DA service-test pressure.pdf\nDear Alice,\nBest,\nPlease see the forwarded message regarding an LOI request. Thank you.\nRachel Mangum (HMIC)\nFrom: Fazzio, Mark P Collins <Mark.Fazzio@collins.com>\nSent: Wednesday, June 22, 2022 11:45 PM\nTo: INFOCNTR (PHMSA) <INFOCNTR.INFOCNTR@dot.gov>\nSubject: Interpretation of 49 CFR 178.47, 178.53 and 178.58\nCAUTION: This email originated from outside of the Department of Transportation (DOT). Do\nnot click on links or open attachments unless you recognize the sender and know the content\nis safe.\nTo whom it may concern,\nPlease see the attached interpretation request.\nThank you,\nMark Fazzio | Chief Engineer, Kidde Fire Suppression\nSensors & Fire Protection Systems | Avionics\nCOLLINS AEROSPACE\n4200 Airport Dr. NW, Wilson, NC 27896\nTel: +1 252 246 7910 | Fax: +1 252 246 8415\nmark.fazzio@collins.com | collinsaerospace.com\nCONFIDENTIALITY WARNING: This message may contain proprietary and/or privileged information of Collins Aerospace\nand its affiliated companies. If you are not the intended recipient, please 1) Do not disclose, copy, distribute or use this\nmessage or its contents. 2) Advise the sender by return email. 3) Delete all copies (including all attachments) from your\ncomputer. Your cooperation is greatly appreciated.\n\n<<<PAGE 6>>>\n\nKidde Aerospace and Defense\n4200 Airport Dr.\nWilson, NC 27896\nMark.fazzio@collins.com\nwww.collinsaerospace.com\nJune 22, 2022\nPipeline and Hazardous Materials Safety Administration\nU.S. Department of Transportation, East Building\n1200 New Jersey Avenue, SE\nWashington, D.C. 20590-0001\nAttention: Interpretations\nSubject: 4D, 4DS and 4DA service and test pressures\nDear Sir/Madam:\nKidde Technologies, KDBA Kidde Aerospace & Defense (KAD), a long time manufacturer\nof pressure vessels used for aircraft and military vehicle fire extinguishing, is requesting\ninterpretation of 49 CFR 178.35(F), 178.47(F, I, J), 178.53(E, H), and 178.58(F, I).\nSpecifically, Kidde seeks confirmation of the following:\n1) Test pressure may exceed 2x service pressure.\n2) Wall thickness stress calculation is based on 2x service pressure, including in\ncases where the test pressure exceeds 2x service pressure.\n3) The wall stress calculated at a test pressure greater than 2x service pressure may\nexceed the stress threshold per 178.47(F), 178.53(E) or 178.58(F), provided the\ncalculated stress at 2x service pressure does not exceed the stated limits.\n4) Processing prior to hydrotesting may be performed at up to 90% of actual test\npressure, including in cases where the test pressure exceeds 2x service pressure.\n5) The actual test pressure may be marked on a low stress attachment as “TP xxxx”\nincluding in cases where the test pressure exceeds 2x service pressure.\nAs an example, please consider a 4D pressure vessel made from 4130 streel with a\nservice pressure of 500 psi. Per the above interpretation it is then acceptable to perform\nthe wall stress calculation at 1000 psi. A test pressure of 1500 psi can be used in the\nmanufacture with a pressure process prior to hydrostatic test not to exceed 1350 psi (1500\nx .9). The wall stress at 1500 psi may exceed 37,000 psi as long as the wall stress at 1000\npsi (2x 500 psi service pressure) does not exceed 37,000 psi. Finally, the test pressure\nmay be marked in addition to the markings per 49 CFR 178.35.\nPlease advise if the above interpretation and example are correct.\nThank you,\nMark Fazzio\nThis document contains no EAR technology or ITAR technical data","truncated":false,"body_characters":12182}