Riddick Engineering Corporation — Hazardous Materials Safety Interpretation

Page 1U.S. Department of Transportation 400 Seventh St., S.W. Washington, D.C. 20590 Research and Special Programs Administration JUL 8 2003 Mr. Chris J. Teas, PE Vice President Ref. No. 03-0035 Riddick Engineering Corporation 4600 West Markham Little Rock, AR 72205 Dear Mr. Teas: This is in response to your letter dated February 11, 2003, and subsequent telephone conversation with Sandra Webb of my staff, requesting clarification of requirements for construction and certification of DOT 407 cargo tanks designed to be loaded by vacuum under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171- 180). Specifically, you ask whether a cargo vacuum tank must be designed and manufactured with full ASME certification as provided in § 178.347-1(c) or to the provisions outlined in § 178.347-1(d). You also ask if, when manufacturing under the provision § 178.347-1(d), the manufacturer is required to be ASME certified as provided in § 107.503(b). Section 178.347-1(c) provides specific requirements for designing and constructing DOT 407 cargo tanks that are loaded by vacuum. Specifically it states, "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 accordance with the ASME Code. The external design pressure for a cargo tank loaded by vacuum must be at least 15 psig." Therefore, a cargo tank designed to be loaded by vacuum must be constructed and certified in accordance with the ASME Code. Additionally, in accordance with § 178.345-1(d) a manufacturer of a cargo tank is required to hold a current ASME certificate of authorization and must be registered with the Department in accordance with 49 CFR part 107 subpart F. This requirement applies if a cargo tank is designed and constructed under §178.347-1(c) or § 178.347-1(d). I hope this information is helpful. If we can be of further assistance, please do not hesitate to contact us. Sincerely, Wain Hany Susan Gorsky Senior Transportation Regulations Specialist Office of Hazardous Materials Standards 178,347 030035 060-4-2-40#

Page 2To: Edward Mazzullo From: Chris J. Teas 2/11/2003 12:10:27 (Page 2 of 2) Webb RIDDICK ENGINEERING CORPORATION 4600 WEST MARKHAM Consultants LITTLE ROCK ARKANSAS 72205 8178.347-1@ FAX 501-374-3790 501-888-7300 CargoTank 03-0035 EDGAR K. RIDDICK IR, PE 1923-1937 FOUNDER February I1, 2003 Mr. Edward Mazzullo EDGAR K. RIDDICK 6, PE PRESIDENT Director, Office of HAZMAT Standards USDOT/RSPA (DHM-10) RIS J. TEAS. I 400 7" Street Southwest CE PRESIDER Washington DC, 20590-0001 Re: Formal interpretation request Code Needing Interpretation: Title 49, SUBTITLE B, CHAPTER I, SUBCHAPTER C, Part 178.347-1 (c) Cargo Tank Description: Cargo tank to be designed and manufactured is as follows: 2. 1. Mobile vacuum tank. (SEE PICTURE BELOW) 3. 1500 gallon. 4. Internal pressure < 15 psig. Stainless steel. 6. 5. Customer: US Government. Used to clean up various hazardous spills. Questions: 1. Does this cargo vacuum tank need to be designed and manufactured with full ASME certification per 178.347-1(c) or by ASME with exceptions per 178.347-1(d)? 2. Regardless, we are designing this tank per ASME standards. However, if this tank falls under (d), then does the manufacturer have to be ASME certified as listed in 107.503(b)? Sincerely, Chris J. Teas, PE Mechanical Electrical Industrial Structural Power & Process Energy Analysis & Computer Modeling Industrial Studios & Macterplanning ENGINEERS SCIENTIFIC CONSULTANTS Co.generation#