Hazmat Environmental Group — Hazardous Materials Safety Interpretation

Page 1Vince Phillips Maintenance Supervisor Hazmat Environmental Group 60 Commerce Drive Buffalo, NY 14218-1040 Reference No. 17-0058 Dear Mr. Phillips: This letter is in response to your June 1, 2017, letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to inspection requirements for the areas on a cargo tank covered by the upper coupler (fifth wheel). You describe a lined cargo tank transporting lading that is corrosive to the tank but due to the lining does not come in direct contact with the tank itself. You ask whether the areas covered by the upper coupler (fifth wheel) must be tested every two years in accordance with § 180.407(d)(2)(ix), even though the tank is lined The answer is yes. Section 180.407(d)(2)(ix) requires that when transporting lading corrosive to the tank, areas on a cargo tank covered by the upper coupler (fifth wheel) must be inspected once every two years for corroded and abraded areas, dents, distortions, defects in welds, and any other condition that might render the tank unsafe for transportation service. The lading you describe is corrosive. Therefore, even though the lading does not physically come in contact with the tank, the HMR require that the inspection be completed every two years. I hope this information is helpful. Please contact us if we can be of further assistance. Sincerely, Standards and Rulemaking Division#

Page 2180.407(d)(2)(ix) For cargo tanks transporting lading corrosive to the tank, areas covered by the upper coupler (fifth wheel) assembly must be inspected at least once in each two year period for corroded and abraded areas, dents, distortions, defects in welds, and any other condition that might render the tank unsafe for transportation service. The upper coupler (fifth wheel) assembly must be removed from the cargo tank for this inspection. The part of "For cargo tanks transporting lading corrosive to the tank" is where my question comes in regarding a lined cargo tank, although the lading in the tank is corrosive to the tank it does not ever touch the tank as it is lined. Could in this instance the coupler removal then go back to following under 180.407(g)(1)(iii) for 5 year pressure testing criteria. We are asking this under the premise in this case where it is an uninsulated, unjacketed, and the upper coupler (fifth wheel) does not interfere with completing a full external visual inspection of the cargo tank, appurtenances, and structural attachments on this cargo tank. Thank you. Sincerely, Vince Phillips Maintenance Supervisor Hazmat Environmental Group 60 Commerce Drive Buffalo NY 14218-1040 vphillips@hazmatinc.com 0-716-748-8267 / C- 716-572-6351 / fax 716-748-8360#