Thompson Tank Inc. — Hazardous Materials Safety Interpretation

Page 1of Transportation U.S. Department Materials Safet ipeline and Hazardou: Washington, D.C. 20590 1200 New Jersey Avenue, SE Administration AUG 2 2 2014 Mr. David L. Thompson Thompson Tank, Inc. P.O. Box 790 Lakewood, CA 90714-0790 Ref. No. 14-0042 Dear Mr. Thompson: This is a response to your February 26, 2014 letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) with regard to the manufacture of DOT specification cargo tanks. This letter requests further clarification of a previous interpretation (Reference No. 13-0207R; see enclosed). Specifically, you seek clarification on the design, construction and certification of DOT 412 cargo tanks designed to be loaded by vacuum. You ask if a vacuum loaded DOT 412 cargo tank having a 15 psig external maximum allowable working pressure (MAWP) must be designed, constructed and certified in accordance with the ASME Code and stamped on the ASME name plate. Specification DOT 412 cargo tanks designed to be loaded by vacuum must have a minimum external MAWP of 15 psig and a minimum internal MAWP of 25 psig in accordance with be constructed and certified in accordance with Section VIII of the ASME Code, in § 178.348-1(c). A DOT 412 cargo tank designed to be vacuum loaded would be required to accordance with § 178.348-1(e)(1) and the name plate must be stamped accordingly. This requirement does not distinguish between internal and external MAWP, therefore a DOT 412 than 15 psig must be constructed and certified in accordance with the ASME Code, cargo tank designed to be vacuum loaded and manufactured with an internal MAWP greater irrespective of the external MAWP. I hope this information is helpful. If you have any more questions, please do not hesitate to contact this office. Sincerely, Rht Sulat Robert Benedict Chief, Standards Development Standards and Rulemaking Division#

Page 2ASME - D.O.T CERTIFICATION THOMPSON TANK, INC. D.O.T. INSPECTION - TESTING DESIGN ENGINEERING • CONSTRUCTION THOMPSON VACUUM-PRESSURE UNITS Suchak $178.345-1 $178.348-1 february 26, 2014 8118.347-1 U.S. DOT PHMSA Office of Hazardous Material Cargo Tanks Standards Attn: PHH-10 14-0042 East building 1200 New Jersey Ave., SE. Washington, DC 20590-0001 Gentlemen, Subject: Vacuum Loading Reference No. 13-0207 We received your interpretation Ref No.: 13-0207 and find your statements directed at a DOT 412 Cargo Tank to be very confusing. The DOT 412 Vacuum-Loaded Cargo Tank is typically designed, constructed and 15 PSI External MAWP. and certified in accordance with the ASME Code for 50 PSI Internal MAWP Item No. 1. Must the 15 PSI External MAWP be designed, constructed, and certified in accordance with the ASME Code and stamped on the ASME Specification Plate. Item No. 2. Must the 15 PSI External MAWP be designed and certified. constructed in accordance with the ASME Code, but not Note: If the DOT-412 Vacuum-Loaded Cargo Tank is really designed and constructed in accordance with the ASME Code for 15 PSI External MAWP the additional cost for Certification is "ZERO." It is already being ASME Code Certified for the internal pressure condition. A very small inconvenience for such a large degree of safety. MAILING: POST OFFICE BOX 790, LAKEWOOD, CA 90714-0790 SHIPPING: 8029 PHLOX STREET, DOWNEY, CA 90241 PHONE: (562) 869-7711 • FAX: (562) 869-7214 • OUT OF STATE: (800) 421-7545#

Page 3Please consider that a DOT 407 Specification Vacuum-Loaded Cargo Tank must comply with Item No. 1 and is in a less severe service. Also that a DOT 412 cannot haul flammable products without the temperature actuated shut-off system required for a DOT 407. Enclosed for your evaluation is an email from Truck Trailer Manufacturer Association (TTMA) regarding regulation proposals to PHSMA and e-mail sent by Danny Shelton. Sincerely, David L. Thompson Thompson Tank, Inc. DLT: rb Encl (1 - email from TTMA 2- email from Danny Shelton)#

Page 4ompson Tank Inc Sent: rom: To: Wednesday, December 03, 2008 7:55 AM Attachments: Subject: W: Vacuum tank hompson Tank Ir vac tanks Recommendation for 218.doc Mr. Dave And the saga continues From: Jeff Sims [mailto:Jeff@ttmanet.org] Sent: Wednesday, December 03, 2008 6:11 AM To: Andre Bourgault; Anthony Van Houdt; Bruce Yakley; Bryan Van De Vyvere; Bryan Yielding ; cfoshe@acrotrailer.com; Girard ; David Perry; David Wagoner; Don Lang; Donnie Alford; Duane Plumski ; Ed Mansell ; Gary Christen; Gary Chad Betts; Chris Budniak; Daniel Tremblay ; Dave Adams; Dave Shannon; David Bailey; David Ball; David Burke; David Spoelstra; Harvey Wallenstein; Jack Mueliner; Jack Rademacher ; Jim Lawler; Jim Pflum; Joe Calonge; Joe House ; Lee Hancock ; Leona Busse; Loy McGee ; Mike Barker; Nathan Roe ; Nick Paulick; Pascal Thibault ; Peter Weis; Ray Heelan; Raymond Schaffer; Rick Connelly; Rick Fahl; Robert Lane; Rosemary Muellner; Russ Hamilton; Scott Hevelone; Sean Wayne Roderick Andersen; Steven McWilliams ; Thomas Ballon ; Thomas Determan; Timothy Rabe; Tom Hitchcock; Vaughn DeVorse ; Subject: Vacuum tanks Good Morning to all, vacuum" clearer in the regulations. The attached wording is being proposed to PHMSA in an attempt to make "loaded by vacuum" and "built to withstand full They are attempting to get this into 218f a non-significant regulation that will not have a comment period, so if we have any heartburn with the wording now is time to discuss it. Have a great day! Jeff Sims TTMA - Engineering Manager 703-549-3014 Fax 703-549-3010 phone www.ttmanet.org#

Page 5178.347-1 (c) states that "Any cargo tank built to this specification with a MAWP greater than 35 psig and each tank designed to be loaded by vacuum must be constructed and certified in conformance with Section VIII of the ASME Code (IBR, see §171.7 of this least 15 psi." subchapter). The external design pressure for a cargo tank loaded by vacuum must be at 178.347-4(b) goes on to say that vacuum relief devices are not required for cargo tanks designed to be loaded by vacuum or built to withstand full vacuum. This wording is confusing and creates the appearance that a cargo tank motor vehicle designed to be loaded by vacuum referenced in 178.347-1(c) and cargo tank motor vehicles built to withstand full vacuum referenced in 178.347-4(b) are not required to have vacuum relief devices because they are required to be constructed and certified in accordance with the ASME Code. One can reach this conclusion because in both cases the "loaded by vacuum and built to withstand full vacuum" mean that the cargo tank wall psi. must meet the structural integrity requirements to withstand an external pressure of 15 There is a clear distinction and intent between the phrase "designed to be loaded by vacuum" and "built to withstand full vacuum". We believe that if a cargo tank manufacturer designs a cargo tank "to withstand full vacuum" that this tank is not required to be certified in conformance with Section VIII of the ASME Code but we also believe that a cargo tank that is loaded by vacuum is required to be constructed and certified in accordance with Section VIII of the ASME Code. The intent of the final user of the equipment will determine whether a tank will be vacuum loaded and required to be a "U" stamped vessel versus a cargo tank that is designed to withstand full vacuum to ensure the tank is not sucked in because of product cooling or during unloading and as a products being transported. result of the cooling of the product suck in moisture from the air and contaminate the We believe it was also the intent of the Department to allow for cargo tanks that are designed to withstand full vacuum but are not "U" stamped vessels to be able to take advantage of the exception in 178.347-4(b). The enforcement community can easily determine by inspecting the accessory equipment installed on the cargo tank motor vehicle and determine if this cargo tank motor vehicle is being loaded by vacuum. Once that has been determined simply verify that the cargo tank motor vehicle has a "U" stamp and compliance with the requirements have been verified. If, however the cargo tank and the intent of the Department is also clear and concise. motor vehicle is not a "U" stamped vessel then non-compliance has also been verified follows. Because of the confusion we intend to clarify section 178.347-1(c) and 178.347-4(b) as §178.347-1 General Requirements#

Page 6178.347-1 (c) Any cargo tank motor vehicle built to this specification with a MAWP greater than 35 psig or each tank motor vehicle designed be loaded by vacuum must be constructed and certified in conformance with Section VIII of the ASME Code (IBR, see §171.7 of this subchapter). The external design pressure for a cargo tank loaded by vacuum must be at least 15 psi. (d) Each cargo tank motor vehicle built to this specification with MAWP of 35 psig or less or designed to withstand full vacuum but not be loaded by vacuum must be "constructed in accordance with Section VIII of the ASME Code" except as modified. §178.347-4 Pressure Relief (b) Type and construction. Vacuum relief devices are not required for cargo tank motor withstand full vacuum in accordance with 178.347-1(d). vehicles designed to be loaded by vacuum in accordance with 178.347-1 (c) or built to#

Page 7D.L. Thompson From: Sent: Danny Shelton <shelton10104@gmail.com> To: Wednesday, February 26, 2014 11:24 AM 'Peter Weis'; Duane Plumski; John Cannon; anthony.vanhoudt@bealltrailers.com; Jack Cc: Rademacher Subject: Tom A. Rogers (Work); Mike Pitts; D. L. Thompson Attachments: Cargo tanks Designed to be loaded by Vacuum Certified ASME Vacuum 13-0207 2.18.2014 pdf Please see the attached interpretation from PHMSA dated February 18, 2014 in response to Dave Thompson's inquiry. Based on this interpretation it is my professional opinion that a cargo tank motor vehicle that is designed to loaded by vacuum must be constructed and certified in accordance with the ASME Code. I believe that also means that and if it is a design consideration then the ASME Data Plate must be marked. the ASME Data Plate must be marked with a minimum external pressure of 15 because that is a design consideration Regards#