Mr. Robert D. Howerton, Ph.D. — Hazardous Materials Safety Interpretation

Page 1U.S. Department of Transportation Wastington, D.C. 20590 400 Sieventh Street, S.W. Pipeline and Administratior Hazardous Materials Safet SEP 2 7 2006 2582 Wood Trail Lane Mr. Robert D. Howerton, Ph.D. Ref. No. 06-0200 Decatur, GA 30033 Dear Dr. Howerton: This is in response to your electronic transmission requesting clarification of the rebuilding of accumulators. Specifically, you ask for a procedure whereby you would Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) as they pertain to the notify and receive corroboration from the U.S. Department of Transportation DOT) or a third party that the rebuilt accumulators can withstand at least 5,000 psi, and that the pressure test apparatus that you are building is capable of testing the accumulators at the transporting accumulators, and whether any records are required to be maintained for the required pressure. Additionally, you ask about exceptions under the HMR applicable to rebuilt accumulators. Under the HMR, if your rebuilt accumulators meet the requirements in § 173.306(f)(1) through (f)(4)(iv), you are not required to submit supperting documentation to the DOT. accumulators meeting the above requirements; however, you may elect to receive The DOT does not verify test results nor does it approve pressure test apparatus for substantiation from a third party. As stated in § 173.306(f)(5), if the accumulators do not approval in accordance with Subpart H of Part 107 before the accumulators may be meet the requirements in § 173.306(f)(1) through (f)(4)(iv), you must apply for an meet the requirements in § 173.306(f)(3). Provided the accumulators have a charging With respect to exceptions applicable to accumulators, you state that the accumulators pressure exceeding 200 psig at 70° F, the articles are not required to be labeled (except for transportation by air) and are additionally excepted from specification packaging requirements provided the articles meet the requirements in § 173.306(f)(2) through equirements by any mode of transportation f(3)(ii). These accumulators are not accepted from the HMR's shipping pape 173-306(f)(3) 060200#

Page 2Finally, we note that you referenced "Nitrogen, compressed," UN1066 in your letter. When selecting a proper shipping name, the name that most appropriately describes the non-liquefied, non-flammable gas, and non-flammable liquids are most appropriately article or material being transported must be chosen. Hydraulic accumulators containing described as "Accumulators, pressurized, hydraulic," UN3164. Pneumatic accumulators described as "Accumulators, pressurized, pneumatic," UN3164. containing non-liquefied, non-flammable compressed gas are most appropriately I hope this information is helpful. Please contact this office if you need additional assistance. Sincerely, Hattie L. Mitchell Office of Hazardous Materials Standards Chief, Regulatory Review and Reinvention#

Page 3M'Intyre 3172.101 Robert D. Howerton 2582 Wood Trail Lane Decatur, GA 30033 404-343-6307 Cylinders 06-0200 August 23, 2006 Mr. Edward T. Mazzullo Director, Office of Hazardous Materials Standards U.S. DOT/PHMSA (PHH-10) Washington, DC 20590-001 Dear Mr. Mazzullo: It is my intention to establish in the near future a business that offers the service of rebuilding Rolls-Royce (and Bentley) hydraulic accumulators. (The accum- were manufactured in the years from 1970 to 1980 roughly. They have an ulators in question were installed on the Rolls-Royce Silver Shadow series, which internal volume of 27 cubic inches and are charged with 1000 psi of nitrogen gas.) With this intention in mind, I quickly became aware that the nitrogen charged recently your Hazardous Materials Transportation Training Modules. I accumulators constituted a hazardous material and for that reason I completed conscientiously completed all the quizzes and passed them with an average score of around 85%, so I feel that I am generally well acquainted with your rules and regulations. Applying the knowledge I acquired I looked up Nitrogen, Compressed in the HMT and noted in column 8A that exceptions were cited in §173.306. Here I noted that my product came under category (f) (3) and would be exempt from labeling and general packaging requirements (we have no intention of shipping the product by air) so long as i) it was shipped as an inside package; ii) it was tested after being rebuilt at a pressure of 3,000 psi and iii) it was designed with a burst pressure of not less than 5,000 psi. I also noted that there was no exerption from your shipping paper requirements when shipped by rail or truck. I trust you will not disagree with these (paraphrased) requirements. I am a graduate engineer with both a bachelor's degree from Swarthmore College and a Ph. D. from Georgia Tech. Until recently I was a licensed Professional Engineer in the State of Georgia (I let the license lapse) ard I have practiced as an engineer for over 40 years. I've used this experience to accomplish two relevant tasks: first of all, I have carefully measured a typical Rolls-Royce accumulator and carried out metallurgical testing on the device and in a 44 page report I have established that the accumulator has a burst pressure#

Page 4of at least 13,000 psi; and secondly, I have designed and am in the process of fabricating a pressure testing apparatus capable of testing each accumulator at a pressure of 3,000 psi after it is rebuilt. So the two principal questions that I address to you are: 1. How can I establish with the DOT that the accumulator I intend to rebuild can withstand at least 5,000 psi? Can I submit my report to your experts for corroboration? Or can I submit the report to a transmit the conclusions of the third party to the DOT? In sum where qualified third party and then what are the procedures needed to do I go from here? 2. How can I establish with the DOT that the pressure test apparatus that I am building is capable of testing the accumulators at the required device. (The photographs will show a hydraulic pressure gage.) And pressure of 3,000 psi? I can submit drawings and photographs of the what records of each test do I have to keep? I will have some more questions at a future date but these are the paramount questions at this time. I will greatly appreciate your giving me the guidance that I need here. Best regards, Robert D. Howerton, Ph.D.#