# Thompson Tank Inc. — Hazardous Materials Safety Interpretation **Citation:** 11-0002 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2011-05-11 11-0002 response to Thompson Tank Inc. concerning 178.345, 178.347, 180.407. ## Document text <<>> U.S. Department ofTransportation Pipeline and Hazardous Materials Safety Administration 1200 New Jersey Avenue. SE Washington. DC 20590 VAY 1 1 20il Mr. David Thompson Thompson Tank Inc. 8029 Phlox Street Downey, CA 90241 Ref. No.: 11-0002 Dear Mr. Thompson: This is in response to your December 28, 20 I 0, letter requesting further clarification ofthe Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) based on a letter issued by this office (Ref. No. 10-0219) regarding inspection and use of non-DOT specification cargo tank motor vehicles constructed from glass fiber reinforced plastics (GFRP) authorized by Department ofTransportation Special Permit, (DOT-SP) 11903. Your questions are restated and answered below: Q. Does DOT-SP 11903 require compliance with § 178.347-1(c)? A. No, § 178.347-1(c) does not apply to non-DOT specification glass fiber reinforced plastic (GFRP) cargo tanks manufactured in accordance with DOT SP-11903 paragraph 7.b(viii). Section VIn of the American Society ofMechanical Engineers (ASME Code) referenced in . § 178.347-1 (c) contains design and manufacturing rules applicable to metallic pressure vessels and is not applicable to GFRP cargo tanks manufactured in accordance with DOT -SP 11903. Q. If § 178.347-1(c) does not apply, is the internal maximum allowable working pressure (MA WP) unlimited? A. DOT -SP 11903 paragrph7.a states that the cargo tank must have a design pressure of 35 psig. For the purposes of DOT-SP 11903, the design pressure is the same as the MAWP. Q. Is vacuum loading permissible without ASME certification? A. ASME certification ("U" stamp) is not required for vacuum loaded non-DOT specification GFRP cargo tanks manufactured in accordance with DOT-SP 11903. Q. Will the DOT correct the applicable special permits that specifically require compliance with § 178.347-1(c)? A. As stated in the response to Question 1, no currently active DOT special permits that authorize the manufacture, marking and sale of non-DOT specification GFRP cargo tanks require compliance with Section VIII of the ASME Code referenced in § 178.347-I(c). <<>> Q. Are GFRP cargo tank motor vehicles manufactured in accordance with DOT-SP 11903 required to meet § 180.407(0(3), which requires thickness testing of the tank wall if affected by a lining or resin rich corrosion barrier failure? A. As specified in DOT-SP 11903 paragraph 7.c, non-DOT specification GFRP cargo tank motor vehicles must meet the requirements in Subpart E of Part 180 for the periodic testing and inspection of DOT 407 and DOT 412 specification cargo tank motor vehicles. In our December 21,2010 letter to you, we stated that the lining inspection requirements of § 180.407(0 do not apply since these cargo tanks do not have a liner. Instead, the cargo tank motor vehicles authorized by DOT -SP 11903 are fabricated with a resin rich corrosion barrier that is part of the GFRP construction. The certificate of compliance you supplied with your letter states this particular non-DOT specification GFRP cargo tank is equipped with a "Durakane 51OA 40 BPO" lining material. Durakane 510A 40 BPO is an epoxy vinyl ester resin. This material comprises the corrosion barrier and not lining material as used in § 178.345-2. Q. Must we verify the minimum shell and head thickness specified on the DOT specification plate and in the manufacturer's certificate of compliance? A. Yes, in accordance with DOT -SP 11903 paragraph 7.c, during periodic inspection, the shell and head thickness must be measured in accordance with § 180.407(i). Q. Can this cargo tank comply with both DOT-SP 11903 and TC 412? A. If the TC 412 specification allows cargo tanks to be manufactured of GFRP, it is possible that a cargo tank can comply with both DOT -SP 11903 and TC 412. DOT- SP 11903 requires conformance with all regulations applicable to a DOT 407 or DOT 412 cargo tank except as specified. DOT specification cargo tanks made in the United States are generally recognized for use in Canada as equivalents to the corresponding Transport Canada specifications. Provided Transport Canada recognizes the DOT special permit, this cargo tank would be suitable for use in Canada. Q. Please define what the DOT considers to be the specific differences between an interior lining and a corrosion barrier. A. The application of a lining material is one option to protect a DOT specification cargo tank motor vehicle from corrosion or abrasion. Typical lining materials applied to the cargo tank wall are rubber, Kynar or polytetrafluoroethylene. A corrosion barrier serves the same purpose as a liner (Le. protect the cargo tank from attack by the lading). In the case of DOTSP 11903 and other GFRP cargo tanks, the corrosion barrier is a thin resin rich area which is part of the cargo tank wall. The requirements of § 178.345-2( c )(2) do not apply to cargo tanks manufactured in accordance with DOT -SP 11903 (see DOT -SP 11903, paragraphs 4 and 7.b(ii». While some persons may use the phrases "lining material" and "corrosion barrier" interchangeably, for the purposes of the HMR, non-DOT specification GFRP cargo tanks manufactured in accordance with DOT -SP 11903 are considered unlined cargo tanks. <<>> Q. Can the visual examination only, as recommended by the cargo tank manufacturers, satisfy the DOT requirements that the "structural integrity of the GFRP cargo tank must be determined prior to the repair or the replacement of the corrosion barrier." Are we correct to assume that this requirement also applies to an interior lining? A. The non-DOT specification cargo tanks manufactured in accordance with DOT -SP 11903 are subject to all requirements of Subpart E of Part 180 including an external and an internal visual inspection, a pressure test, and a leakage test (see DOT-SP 11903 paragraph 7.c). In accordance with the table in § 180A07(c), if the cargo tank is equipped with a liner, the lining must be inspected as required by § 180A07(f), and for unlined cargo tanks, the shell and head thickness must be measured in accordance with § 180A07(i). Q. When will the DOT inform the manufacturers of the GFRP cargo tanks of their responsibilities and enforce compliance? A. The Pipeline and Hazardous Materials Safety Administration independently reviews and evaluates the information provided in each special permit application and application for renewal. This review includes a technical analysis, an evaluation of the past compliance history of the applicant (including incident history and enforcement actions) and coordination with the other modal administrations to gather additional relevant information. If you are aware of a manufacturer or inspection facility that does not comply with the HMR or the terms of a DOT special permit, you may file a complaint at http://www.phmsa.dot.govlhazmatJenforcement or contact our enforcement office directly at (202) 366-4700. I hope this answers your inquiry. Ifyou need additional assistance, please contact the Standards and Rulemaking Division at (202) 366-8553. Sincerely, BenSupko Chief, Standards Development Standards and Rulemaking Division <<>> ASME .D.O.T. CERTIFICATION mOMPSON TANK, INC. D.O.T. INSPECTIONS· TESTING DESIGN ENGINEERlNG· CONSTRUCTION December 28,2010 U.S. Department of Transportation PHMSA Office of Hazardous Materials Standards Attn: PHH-10 East Building 1200 New Jersey Avenue, SE Washington, D.C. 20590-0001 Attention: Mr. Ben Supko Acting Chief, Standards Development Standards and Rulemaking Division 10-0219 Dated: December 21,2010 Ref. No.: Gentlemen: Thank you for your prompt reply. My questions as you chose to paraphrase do not accurately represent my request for interpretations. I will attempt to be more specific. Q1. Is 178.347-1 (c) applicable as specifically required in DOT-SP-11903, Section b., paragraph (viii), page 5? If 178.347-c (c) is not applicable is the internal MAWP unlimited and is vacuum loading permissible without ASME Code Certification? Will DOT correct the applicable special permits that specifically require compliance with 178.347-1 (c)? Q2. Are GFRP cargo tank motor vehicles manufactured in accordance with DOT -SP-11903 required to meet 180.407 (f) (3) which requires thickness testing ofthe tank wall if affected by a lining or a resin rich corrosion barrier failure? , Must we verify the minimum shell and head thickness specified on the DOT Specification Plate and in the manufacturer's Certificate of Compliance? We have attached a copy of Comtank'S Manufacturer's Certificate of Compliance for the 2008 FRP tank trailer, Serial No. ZC9LTAB28B075487 in question. SHIPPING: 8029 PHLOX STREET, DOWNEY, CA 90241 MAILING: POST OFFICE BOX 790, LAKEWOOD, CA 90714-0790 PHONE: (562) 869-7711 • FAX; (562) 869-7214 • OUT OF STATE; (800) 421-7545 <<>> Please note that the manufacturer's DOT Certificate of Compliance specifies the following: 1. Complies with TC 412 as shipped. 2. Minimum shell thickness .50 inches. Minimum head thickness .75 inches. 3. Lining Material Durakane 510A 40 BPO. Q3. Can this cargo tank comply with both DOT -SP-1193 and TC 412? Q4. Please define what DOT considers to be the specific differences between an interior lining and a corrosion barrier. Derakane is a rather ineffective and economical lining material, only one ofmany, that is applied to carbon steel, aluminum, stainless steel and FRP cargo tanks. The Derakane lining applied to the interior of the above identified cargo tank has been replaced or repaired many times in the past, twice in the last three months. Q5. Can the visual examination only, as recommended by the manufacturers, satisfy the DOT requirement that "the structural integrity ofthe GFRP cargo tank must be determined prior to the repair or the replacement ofthe corrosion barrier." Are we correct to assume that this requirement also applies to an interior lining? We do not understand how a visual examination can verify the minimum thickness, or the structural integrity ofthe cargo tank wall, such as stress cracks, impact damage, brittleness or laminations. The manufacturers we have spoken with were unable to provide any recommended procedures that they believe would ensure that the structural integrity of the GFRP cargo tank motor vehicle had not been adversely affected. Q6. When will DOT inform the manufacturers ofthese GFRP cargo tanks of their responsibilities and enforce compliance? Please give this request your earliest consideration as other manufacturers, inspection and repair facilities, in addition to ours, requires clarification to resume providing these services to our customers. ~---------------~ DLT/cs Page 2 of2 <<>> _-..,-""I-""... .,...-.,-,-----"'"--~#'---8"-".4"''''-''',~~'''_~_''' ___'''"_~ .... SJ»".,",.$" ~ ~ ~ , f COMPTANK CORPORATION i ! CERTIFICA TE OF COMPUANCE I Capacity: 5500 U5 Gal Serial Number: 2cgLTA2B28B075487 ~ This certifies that to the extent of the work performed by the manufacturer, the f new cargo tank identified below, as well as the fittings, valves, piping and , , ~ protective devices were designed, constructed and tested in accordance with both , t the U.S. Department of Transportation Motor Vehicle Specifications and I , ~ ; DOT SP 11903 along with Transport canada B620-2003 and TC 412 for cargo , , , ~ tanks used for the transportation of hazardous materials and dangerous goods. i i,' Using 1-35# pressure relief vent and l ..SHg vacuum breaker per tank. , I Vehicle Type: FRP TANK TRAILER , Year Fabricated: ____2:m;O .. 08...x..___ , ~ I ; , • Date Shipped: -----: ~ l Manufacturer: Comptank Corporation CT # 0024 30817 Zone Rd # 8 _~ ~ I Bothwell, Ontario Design Certifying Engineer: l.M. Plecnlk CT # 7533 1250 Bellflower Blvd I Long Beach, CA Registered Inspector: Harold Marcus Ltd. H ani Simpson I I , , , ; ~ _ t t , , t , CT # 15445 15124 Longwoods Rd. , , ~ , Bothwell, Ontario S I Pressure test performed by: Benson Herr , , I , I DOT 11903 as shipped MCARGO TANK COMPLIES WITH I ~ CARGO TANK COMPLIES WITH I TC 412 lIS lhIppedu , ~ t • t ; , t I J t II UTe 412 Certification does not include Class 3 l'lUlteriais for veuels manufactured after August 1&. 2002 , r , f: , SERIAL # 2CQL],A2E28E075487 T.C.R.N. 25-0037 T.C. ill ~ D.O.T. SP119Q3 Orlglnaltestdate: Feb 15( 2008 MAWP 35 PST : lEST PRESSURE 52 PSI Des. Temp Range Q:W F Max Lading Density 161bs/gal ~ WELD MATERIAL NI.A SHELL MATERIAL FRP 510A HEAD MATERIAl rRP 510A i MIN. SHaL THICKNESS .50 In MIN. HEAD THICKNESS .ZS In MFO SHEU. THICKNESS...sQJn ~ I MFO HEAD THICKNESS ~ EXPOSED SURFACE AREA 680 s 9 f t I TOTAL CAPAOTY - Utres 2181 U.S.G. 5680 MAX PAYLOAD 72 t 000 Ibs i MAX LOAD RATE 200 GPM @ 35 P5IG VAOJUM FULL ~ MAX UNLOAD RATE 200 GPM @ 35 PSlG LINING MATERIAL Derakaoe 51 O~ 40 BPO ~ C.T. CERTIFICATION DATE February 15 toe M.D.l.N. 04-12-16 cr MFR. QQ21 i HEATING SYSTEM PRESS XXXXX HEATING SYSTEM TEMP XXXXX S I C.T. DATE OF MANUFACTURE February 20Q8 EXEMPTION NO. SP 11903 i , f • ~~~~~ .'R. • • _____~ __ __ ______~_~ ____~r_~ ____~ __ _______ __________.-.#,,~#J Reglste~r ';;MO¥~ lteuu not Installed at time of shipment {} Elcc:trical groulllbng for 0_ 3 rtUIIeoals per 8620-03 Section H H ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `3de339d4b290bddf8e304e2ab7cb2b391acca0459cf676bbf6d82aec14874d05` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-22T02:52:10.856Z - Document slug: `phmsa-interpretation-11-0002` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "Thompson Tank Inc." ], "individuals": [ "Mr. David Thompson" ], "refIds": [ "11-0002" ], "catalogDates": [ "2011-05-11" ], "catalogParts": [ 178, 180 ], "catalogRowCount": 3, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/62096" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "178.345", "178.347", "180.407" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/178345-2", "https://www.phmsa.dot.gov/regulations/title49/section/178347-1", "https://www.phmsa.dot.gov/regulations/title49/section/180407" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretations/2011/110002.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretations/2011/110002.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretations/2011/110002.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/11-0002-f77541a80c.pdf", "pdfArtifactSha256": "beb5e2e40c8bae5dc633491a05562bf3e997ce567ea73431757255cab5ec9d3a", "extractedTextPath": "data/sources/phmsa-interpretations/11-0002-f77541a80c.v2.txt", "extractedTextSha256": "7572eb4e606ba8021ab157d0efc3a75b422093a80a691871ff5082cbf52772f1", "pageCount": 6, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```