{"operation":"document","citation":"16-0082","title":"Truck Trailer Manufactures Association (TTMA) — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2017-05-31","effective_on":null,"summary":"16-0082 response to Truck Trailer Manufactures Association (TTMA) concerning 178.345.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-16-0082.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-16-0082.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-16-0082","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2017/160082.pdf","body":"<<>>\n\nEngineering Manager\nTruck Trailer Manufacturers Association (TTMA)\n7001 Heritage Village Plaza, Suite 220\nGainesville, VA 20155\nReference No. 16-0082\nDear Mr. Freiler:\nThis letter is in response to your May 11, 2016, email requesting clarification of the Hazardous\nMaterials Regulations (HMR; 49 CFR Parts 171-180) applicable to the accident damage\nprotection requirements for certain specification DOT cargo tank motor vehicles (CTMVs) found\nin § 178.345-8. Specifically, you ask about the requirement for protecting piping, or any device,\nthat if damaged in an accident could result in loss of lading.\nWe have paraphrased and answered your questions as follows:\nQ1.\nYou seek confirmation of your understanding that the requirement to provide protection\nof 'piping, or any device, that if damaged in an accident could result in the loss of lading'\nin § 178.345-8(a)(2) extends to components such as the dust cap, which do not carry\nlading during transit but could transfer significant forces to areas that do contain lading.\nAl. Your understanding is correct.\nQ2. You seek confirmation of your understanding that the 6-inch horizontal set-back design,\nrequired as part of the rear-end protection provision in § 178.345-8(d)(1), also applies to\nthe dust cap, arms, and hand valves even if these elements do not normally carry lading\nduring transit.\nA2.\nYour understanding is correct. The dust cover and hand valve must be included in the 6-\ninch horizontal set-back design as they are part of the piping system. However, if the\npiping includes a stop valve and a sacrificial device such as a shear section, then the\npiping is considered protected.\nQ3.\nYou ask whether the requirement in § 178.345-8(a)(2) concerning protection against loss\nof lading as mentioned in Q1 applies to other cargo tank piping that is attached but not\nassociated with an outlet valve. You also ask whether § 178.345-8(a)(2) applies to air or\nvapor lines installed according to good industry practice (e.g., TTMA RP 102).\n\n<<>>\n\n§ 178.345-8(d)(1) do not apply to piping that if damaged in an accident could result in a\nloss of lading from the cargo tank but is not required by the applicable specification.\nI hope this information is helpful. Please contact us if we can be of further assistance.\nSincerely,\nChief, Standards Development\nStandards and Rulemaking Division\n\n<<>>\n\nPlease enter this letter of interpretation request, and assign it to Matt Nickels.\nThanks,\nM\nFrom: John Freiler [mailto:john@ttmanet.org]\nSent: Wednesday, May 11, 2016 10:42 AM\nTo: Nickels, Matthew (PHMSA)\nCc: Carrie Renuart; Jeff Sims; Nancy Livingston\nSubject: Re: Request for interpretation re: piping setback.\nHi Matt,\nSee the attached letter and RP. It should address your concerns; if not, let me know.\nThanks!\nJohn Freiler - Engineering Manager\nTruck Trailer Manufacturers Association\n7001 Heritage Village Plaza\nSuite 220\nGainesville, VA 20155-3094\n703-549-3010 - Phone\n\n<<>>\n\nPHMSA-Office of Hazardous Materials Standards\nAttn: PHH-10\nEast Building\n1200 New Jersey Ave, SE\nWashington, DC 20590\nPhmsa.hm-infocenter@dot.gov\nSubject: Request for Interpretation\nDear Sirs;\nThe Truck Trailer Manufacturers Association (TTMA) is an international trade association representing approximately\n90% of the trailers manufactured in the United States. This request for interpretation concerns §178.345-8 Accident\nDamage Protection and the interactions between paragraphs (a)(2) and (d) of that section.\nIt has come to TTMA's attention that the agency is considering that the requirement for protecting \"piping, or any\ndevice that if damaged in an accident could result in loss of lading\" in §178.345-8(a)(2) includes the dust cap and its\narms when evaluating the 6\" horizontal set-back rule in $178.345-8(d)(1) even if such are not normally carrying\nlading. The rationale is that the dust cap and other components are substantial and could transfer significant forces\nthrough to areas that do contain lading in transit. See the following photo:\nOur concern is if PHMSA views the hand valve and dust\ncap to be an extension of the piping. which, despite not\ncontaining lading during transit, could damage the lading\ncontaining portions of the cargo tank; such thinking could\nbe used expansively for other cargo tank piping not\nassociated with the bottom outlet valve shown in the\npicture.\nCompressed air and vapor lines are often run to the top of\nthe cargo tank to provide ground level access points for\noperators as a safer alternative to ascending the ladder of\nthe cargo tank with hoses to either inject air or remove\nvapors. A common industry practice is shown in the\naccompanying illustration:\n\n<<>>\n\n-SIDE OF LANK HE RUM\nLAFOR LEE TO RUNN\nTO FEAR DF THALER\nTHA RP NO. 102, FIGURE TWO\nAs can be seen in the drawing, the piping involved does not pose a risk of tank puncture in a rear end collision: it is\nboth too long and narrow to transfer significant accident damage loads into the shell of the tank, and it is protected by a\nsacrificial segment as it enters the overturn protection.\nWe would like you to clarify that the \"piping or any devices that if damaged in an accident could result in a loss of\nlading\" referred to in §178.345-8(a)(2) does not include air or vapor lines installed according to good industry practice\nsuch as that described in TTMA RP 102. (copy attached) Further, that the 6\" set-back provisions contained in\n§178.345-8(d)(1) also do not apply to these air or vapor lines.\nnot hesitate to contact the undersigned.\nThank you for considering our request for interpretation. If you have any questions concerning this letter, please do\nSincerely,\nJohn Freiler\nEngineering Manager\nEnc.\n\n<<>>\n\nwww.ttmanet.org\nTitle: Vapor Recovery Line Configurations for DOT 407 and DOT 412 Cargo Tanks\nPrevious Editions:\nOriginally Issued April 2002; Reissued May 2008, April 2013.\n1.0\nPreface:\n1.1\nNo part of this document may be reproduced or transmitted in any form or by any means, electronic or\nwritten permission from the Truck Trailer Manufacturers Association.\nnechanical, including photocopying, recording, or by any information storage or retrieval system withou\n1.2\nRecommended Practices and Technical Bulletins are furnished by the TTMA as a guide to general practices in\nthe manufacture, use, and repair of truck trailers. However, the scope of the TTMA's Recommended Practices\nand Technical Bulletins is not exhaustive of all general practices in the manufacture, use, and repair of truck\ntrailers and there may exist such general practices which do not appear in either the Recommended Practices or\nTechnical Bulletins.\n1.3\nRecommended Practices and Technical Bulletins represent the state-of-the-art that existed at the time of its\npreparation. Users of Recommended Practices and Technical Bulletins should familiarize themselves with\nadvancements in practices that have occurred subsequent to the Recommended Practice's or Technical\nBulletin's publication date.\n1.4\nThe TTMA has not undertaken any evaluation of all the conceivable ways in which Recommended Practices\nor Technical Bulletins may be used by manufacturers, users, or repairers of truck trailers nor the consequences\nof such uses. Everyone who uses Recommended Practices or Technical Bulletins must first satisfy himself or\nherself that his or her safety, the safety of others, or the safety of the truck trailer and any other equipment will\nnot be jeopardized by their use of information contained within the Recommended Practices or Technical\n1.5\nThe Recommended Practices and Technical Bulletins may contain terms or words with specialized meanings.\nNomenclature or TTMA RP No. 66 - Trailer Nomenclature.\nDefinitions for such terms or words may be found in TTMA RP No. 36 - Tank Trailer and Tank Container\n1.6\nWithin the Recommended Practices and Technical Bulletins, \"shall\" is used wherever conformance with the\nTTMA publication requires that there be no deviation from the specific recommendation. \"Should\" is used\npublication.\nwherever deviation from the specific recommendation is permissible in complying with the TTMA\nConformity with TTMA publications by manufacturers, users and repairers of truck trailers is voluntary and\nany non-conformity with such publications is not indicative of the non-conforming practice being deficient.\nAny inclusion of Recommended Practices or Technical Bulletins within any contract, document or standard is\nvoluntary, and any such inclusion shall not imply any endorsement or approval by the TTMA due to the\nmultitude of ways in which the Recommended Practices or Technical Bulletins may conceivably be used.\n\n<<>>\n\nstandardization controls equipment cost by precluding the development of several unique\ndevices and line designs, and preventing the need for each carrier to create line\nspecifications.\n2.3\nThe configurations established may not work for all applications. Therefore, the personnel\nemployed by companies using these configurations must determine if a tank trailer's vapor\nrecovery line meets essential criteria for the loading/unloading of particular products at\nspecific sites.\n2.4\nThis RP is not intended to address the retrofit of vapor recovery systems on existing cargo\ntanks. Such an activity requires the involvement of a design certifying engineer to satisfy\nthe requirements of 49 CFR 180.413.\n2.5\nSimilarly, this RP is not intended to cover the proper methodology for cleaning vapor\nrecovery lines. Such methodology is the responsibility of the cleaning facility and the\noperators of the cargo tank.\n3.0\nBackground\nIncreasingly, the recovery of potentially harmful vapors associated with certain hazardous materials\nhas become mandated by Federal, state and local governments, and by shippers. Accordingly, DOT\n407 and DOT 412 cargo tanks are commonly specified with a line to recover vapors during loading\nand unloading.\n4.0\nTee Style Hydraulically Actuated Vapor Recovery Valve (hereinafter, VR-valve)\n4.1\nDimensions\n4.1.1\nThe over-all height of the VR-valve when closed shall not exceed eight and one-half\n(8.5) inches. Where possible, the CTMV manufacturer should provide adequate top\naccident damage protection clearance to facilitate the use of a VR-valve with a\nheight of 8.5 inches even if the original equipment VR-valve has a lesser height.\n4.1.2\nThe over-all width of the VR-valve, measured from outlet to outlet, shall be seven\n(7) inches.\n4.1.3\nThe measurement from the tank seal face to the centerline of the VR-valve outlets\nshall be three and three-sixteenths (3.1875) inches.\n\n<<>>\n\nattact pressure of the cargo\ntank's self-closing stop-valve is at least 50 psi greater than the VR-valve fitted on the\ncargo tank.\n4.2.3\nIn some cases, operating personnel may need to open the VR-valve without opening\nthe cargo tank's self-closing stop-valve: One such case is the application of pressure\nto the tank through the VR-valve after the tank is loaded. The plumbing schematic\nin Figure Five illustrates how to accomplish this isolated valve opening. By using a\nmanual control valve with an internal check valve in the hydraulic line to the self-\nclosing stop-valve, the VR-valve can be isolated. The internal check valve allows\nfree flow back to the pump or remote control device in case the control valve is\ninadvertently closed after opening the self-closing stop-valve. The check valve\nfeature must be present to satisfy the requirements of 49 CFR 178.345-11(b)(1).\n4.3\nPositive indication of opening\n4.3.1\nThe VR-valve shall have a visual means to provide positive indication of its\nactuation. If the indication cannot reasonably be made visible, another means of\npositive indication should be provided. This other means of indication may be\naudible or electronic.\n4.3.2 The VR-valve shall be designed and manufactured to preclude the possibility of a\nfalse indication of opening.\n4.4\nFlow\n4.4.1\nThe VR-valve shall be marked with its minimum through area in square inches when\nfully open.\n4.4.2 When loading or unloading, the pressure drop through the vapor recovery system\nincludes losses at the VR-valve, the piping on the cargo tank and any hoses, piping\nand valves at the shipper's or consignee's facility. The absolute pressure in both\ntanks and the piping further affects these losses. All of these losses (if known)\nshould be accounted for by the design certifying engineer when establishing the\nmaximum allowable loading and unloading rates for the cargo tank.\n\n<<>>\n\n4./\nVutlet Ports\n4.7.1\nThe outlet ports of the VR-valve shall be 2\" male NPT connections.\n4.8\nIsolation of Hydraulics\n4.8.1\nThe hydraulics of the VR-valve shall be isolated from any space that may come in\ncontact with products transported in the cargo tank.\n5.0\nTop Configuration\n5.1\nPressure Gauge\n5.1.1\nA pressure gauge shall be provided in the spilldam to allow operators to read tank\npressure.\n5.1.2 Another gauge to read line pressure may be provided if specified by the end user.\nBecause of the limited volume of air contained within the top vapor recovery line,\nthis gauge is not mandatory.\n5.2 Placement of VR-valve\n5.2.1 The VR-valve shall be located as close as practicable to the transverse and\nlongitudinal centerline of the spilldam.\n5.2.2 When possible, the top unload outlet port of the VR-valve should be located above\nthe respective spilldam side to facilitate ease of connecting the plant vapor line.\n5.2.3 If a ladder is attached adjacent to the spilldam, the VR-valve should be placed in a\nlocation on the longitudinal axis of the tank to allow an operator to connect the plant\nvapor line while supported on the top platform of the ladder.\n5.3 Top Vapor Recovery Line\n5.3.1 The top vapor recovery line shall extend off the ladder side of the VR-valve and\nconsist of a 2\" ball valve followed by a 2\" camlock adapter and dust cap.\n5.3.2 This line shall be braced by a support attached to the respective spilldam side (and\nnot the spilldam floor).\n\n<<>>\n\nana consist of a 2 union and 2\" (minimum) inside diameter piping over the spilldam\nside to the outlet area of the cargo tank.\n6.1.2\nInside the spilldam area a vertical sacrificial device shall be provided. This device\nmust break under strain at no more than 70% of the strength of the weakest piping\nelement between the VR-valve and the sacrificial device.\n6.1.3\nThis line shall be braced by a support attached to the respective spilldam side (and\nnot the spilldam floor) located inside of the sacrificial device specified in 6.1.2.\n6.1.4 A minimum slope shall be provided in the entire bottom vapor recovery line to\nassure complete drainage of any liquid.\n6.1.5\nNear the outlet of the cargo tank the following devices and fittings shall be provided:\n6.1.5.1\nA gauge to read line pressure,\n6.1.5.2\nA 2\" ball valve, and\n6.1.5.3\nA 2\" camlock adapter and dust cap.\n6.2\nReferences\n6.2.1 For visual representation of the bottom configuration, see Figures Two and Three in\nthe Appendix.\n7.0\nMulti-Compartment Cargo Tanks\nMulti-compartment cargo tanks manufactured to the DOT 407 or DOT 412 specifications may haul\ndissimilar products in different compartments. Therefore, to preclude contamination the vapor\nrecovery lines on multi-compartment tanks should not be manifolded.\n8.0\nAppendix\n8.1\nFigure One: Top of Tank\n8.2\nFigure Two: Bottom of Straight Round Tank\n8.3\nFigure Three: Bottom of Double Conical Tank\n8.4\nFigure Four: VR-Valve Standard Dimensions\n8.5\nFigure Five: Optional Hydraulic Plumbing Schematic\n\n<<>>\n\nREF. 2\"\nBALL VAL\nVAPOI\nTANK TO\nDETAIL \"A\"\nTTMA RP NO. 102,\nLOCATION\nOF GAUGE\nREF. 2\" CAM STYLE\nADAPTER AND DUST CAP\nSEE DETAIL \"A\"\nVACUUM\nBREAKER\nPRESSURE\nRELIEF VENT\n\n<<>>\n\nREF. 2\" CAM\nSTYLE ADAPTER\nAND DUST CAP\nREF. 2\" BALL VALVE\nREF. GAUGE\nTIMA RP NO. 102, FIC\nVAPOR LINE TO RUN DOWN\n- SIDE OF TANK THEN RUN\nTO REAR OF TRAILER\n\n<<>>\n\nTIMA RP NO. 102, FIG\nHYDRAULIC\nHAND PUMP\nVAPOR LINE TO RUN\nDOWN SIDE TO BOTTOM\nCENTERLINE OF TANK THEN\nFORWARD TO OUTLET AREA\n\n<<>>\n\n8 1/2\" MAX VALVE HEIGHT\nTTMA RP ND. 102,\n3.1875'\n-TANK NIPPLE\n3 1/2°\n7°\nVALVE ENVELOPE —\n2' NPT\n3* NPT SWIVEL CONNECTION\n\n<<>>\n\nTIMA RP NO. 102,\nHYDRAULICALLY OPERATEL\nSELF-CLOSING STOP-VALI\nFUSIBLE/FRANGIBLE\nREMOTÉ CONTROL\nDEVICE\nTEE STYLE HYDRAULICALLY ACTUATED\nVAPOR RECOVERY VALVE\nMANUAL SELECTOR\nVALVE WITH INTERNAL\nCHECK VALVE\nWARNING!\nCHECK VALVE MUST BE INSTALLED SO THAT HYDRAULIC\nPRESSURE CAN BE RELIEVED FROM SELF-CLOSING STOP\nVALVE BY ACTUATION OF FUSIBLE/ FRANGIBLE EMERGENCY\nREMOTE CONTROL DEVICE, EVEN IF MANUAL SELECTOR\nVALVE IS CLOSED.\nHYDRAULIC\nPUMP &\nRESERVOIR","truncated":false,"body_characters":16567}