Truck Trailer Manufacturers Association — Hazardous Materials Safety Interpretation

Page 1- Karem of Transportation U.S. Department Washington, D.C. 400 Seventh Street, S.W. 20590 Research and Special Programs MAY 5 1998 Administration Mr. Donald W. Vierimaa Vice President-Engineering Truck Trailer Manufacturers Association 1020 Princess Street Alexandria, VA 22314 Dear Mr. Vierimaa: This is in response to your letter requesting clarification of your understanding that when calculating the static stresses of non-American Society of Mechanical Engineers (ASME) Code stamped DOT 400 series cargo tanks in accordance with § 178.345-3(b), the requirement specified in § 178.345-3(a) (2) is applicable. Your understanding of §§ 178.345-3(a) and (b) is correct. In cases where actual physical property tests of materials are certified showing an actual ultimate tensile strength greater than that shown in the ASME Code or the American Society for Testing and Materials (ASTM) standard, the ultimate tensile strength of the material used in the design may not exceed 120% of the minimum ultimate strength specified in the ASME Code or the ASTM standard. Section 178.345-3(a)(2) is applicable for the calculation of the static stresses of non-ASME DOT 400 series cargo tanks in accordance with §§ 178.345-3(b) and (c). I apologize for the delay in preparing this response and hope that it has not caused you any inconvenience. If you need further assistance, please contact us. Sincerely, Than I. Allan Thomas G. Allan Senior Transportation Regulations Specialist Office of Hazardous Materials Standards 98 - 0598 178,345-3#

Page 2; Truck Trailer Manufacturers Association HM Khrim 178345 1020 PRINCESS STREET ALEXANDRIA, VA. 22314 RICHARD P. BOWLING PRESIDENT 4-20-4 FAX: 1-703-549-3014 (703) 549-3010 June 15, 1995 Edward T. Mazzullo Director, Office of Hazardous Materials Standards Research & Special Programs Administration U.S. Department of Transportation Washington, D.C. 400 Seventh Street, S.W. 20590 Subject: Applies to 178.345-3(b), Static Stress Calculations Dear Mr. Mazzullo: allowable stress prescribed in the ASME Code or 25 percent of the tensile . 178.345-3(a) states that the calculated design stress may not exceed the Strength of the material used. 178.345-3(a) (2) states that if 25 percent of actual tensile strength shall be The material used. detexmined by physical property tests of the .. • non-ASME DOT 406, DOT 407, or DOT 412 cargo tank in accordance with Please confirm that in the calculation of the static stresses of a 178.345-3(b), that 178.345-3(a) (2) is applicable. some cases an allowable tensile strength up to 120 percent of that specified in This would mean that in and construction of a cargo tank in accordance with Section VIlI, Division 1 either the ASME Code or the ASTM standard may be used in the static design Sincerely, Donald W. Vierimaa DWV/mm Vice President-Engineering cc: Tank Conference Engineering Committee#

Page 3MAY - S 1998 Mr. Donald W. Vierimaa Vice President-Engineering Truck Trailer Manufacturers Association 1020 Princess Street Alexandria, VA 22314 Dear Mr. Vierimaa: This is in response to your letter requesting clarification of your understanding that when calculating the static stresses of non-American Society of Mechanical Engineers (ASME) Code stamped DOT 400 series cargo tanks in accordance with § 178.345-3(b), the requirement specified in § 178.345-3(a) (2) is applicable. Your understanding of §§ 178.345-3(a) and (b) is correct. In cases where actual physical property tests of materials are certified showing an actual ultimate tensile strength greater than that shown in the ASME Code or the American Society for Testing and Materials (ASTM) standard, the ultimate tensile strength of the material used in the design may not exceed 120% of the minimum ultimate strength specified in the ASME Code or the ASTM standard. Section 178.345-3(a)(2) is applicable for the calculation of the static stresses of non-ASME DOT 400 series cargo tanks in accordance with §§ 178.345-3(b) and (c). I apologize for the delay in preparing this response and hope that it has not caused you any inconvenience. If you need further assistance, please contact us. Sincerely, Thomas G. Allan Senior Transportation Regulations Specialist Office of Hazardous Materials Standards Jkarim:dhm-12:68553:04/08/98 Revised:chh: 04/29/98 File: 178.345-3 SC: 333#