Interpretation Response #18-0090
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
May 02, 2019
Mr. Michael R. Kloesel
American Bureau of Shipping (ABS)
Corp. Container Certification Dept.
16855 Northchase Drive
Houston, TX 77060
Reference No. 18-0090
Dear Mr. Kloesel:
This responds to your June 11, 2018, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to United Nations (UN) portable tanks. Specifically, you describe several scenarios and observations related to the design, approval, construction, and use of UN portable tanks. Your questions are paraphrased and answered as follows:
Q1. Are UN portable tank manufacturers required to indicate the hazardous material or group of hazardous materials intended to be transported to a design approval agency?
A1. The answer is yes. As prescribed in § 178.273(b)(7)(ii), the UN portable tank design approval agency must issue a certificate to the manufacturer that refers to the prototype test report, the hazardous material or group of hazardous materials allowed to be transported, the materials of construction of the shell and lining (when applicable) and an approval number.
Q2. Absence of information regarding the specific commodity to be transported in a UN portable tank prevents verification of compatibility with the tank. Is this a correct statement?
A2. The answer is yes. As prescribed in § 178.274(b)(2)(i), portable tank shells, fittings, and pipework shall be constructed from materials that are compatible with the hazardous materials intended to be transported. Further, § 178.273(b)(7)(ii) requires that the approval certificate issued by the approval agency certify that the UN portable tank design is suitable for its intended purpose and meets the requirements of the HMR. More specifically, the approval certificate must refer to the hazardous material or group of hazardous materials authorized to be transported in the UN portable tank. Thus, the specific commodity intended to be transported in the portable tank must be known beforehand to verify compatibility with the tank.
Q3. A portable tank approval stipulates that an approval to a higher T-Code satisfies the design requirements of a lower T-Code. Is this a correct statement?
A3. The answer is yes, provided certain requirements are met. As prescribed in
§ 172.102(c)(7)(v), an alternate portable tank instruction may be used if:
- The alternative portable tank has a higher or equivalent test pressure (for example, 4 bar when 2.65 bar is specified);
- The alternative portable tank has greater or equivalent wall thickness (for example, 10 mm when 6 mm is specified);
- The alternative portable tank has a pressure relief device as specified in the "T" Code. If a frangible disc is required in series with the reclosing pressure relief device for the specified portable tank, the alternative portable tank must be fitted with a frangible disc in series with the reclosing pressure relief device; and
- With regard to bottom openings—
- When two effective means are specified, the alternative portable tank is fitted with bottom openings having two or three effective means of closure or no bottom openings; or
- When three effective means are specified, the portable tank has no bottom openings or three effective means of closure; or
- When no bottom openings are authorized, the alternative portable tank must not have bottom openings.
Q4. All UN portable tanks, and not just those required to be U-stamped, must be designed and constructed in accordance with Section VIII, Division 1 of the American Society of Mechanical Engineers (ASME) Code. Is this a correct statement?
A4. The answer is yes. As prescribed in § 178.274(b)(1), shells must be designed and constructed in accordance with Section VIII of the ASME Code. However, as prescribed in § 178.274(a)(2), the technical requirements applicable to UN portable tanks may be varied if approved by the Associate Administrator and the portable tank is shown to provide a level of safety equal to or exceeding the requirements of the HMR. Portable tanks approved to alternative technical requirements must be marked "Alternative Arrangement" as specified in § 178.274(i).
Q5. Are materials of construction prescribed in the ASME Code only required on a U-stamped UN portable tank?
A5. The answer is no. As prescribed in § 178.274(b)(1), the materials of construction prescribed in the ASME Code are required on all UN portable tanks designed and constructed in accordance with the ASME Code, except as limited or modified in the HMR.
Q6. We have observed offshore portable tanks from Europe designed under an alternative arrangement that do not meet the remote operation of valve requirements in 188.8.131.52.3.1.4 of the International Maritime Dangerous Goods (IMDG) Code. Is this practice acceptable in the United States?
A6. The answer is yes, provided such portable tanks meet certain requirements. Under
§ 173.24(d)(2) of the HMR, a UN standard packaging manufactured outside of the United States in conformance with national or international regulations based on the UN Recommendations on the Transportation of Dangerous Goods (UN Recommendations) is an authorized packaging, as this term is defined under § 173.24(c)(1), when: (1) the packaging fully conforms to applicable provisions in the UN Recommendations and the requirements of subpart B part 173 of the HMR, including reuse provisions; (2) the packaging is capable of passing the prescribed tests in part 178 of the HMR applicable to that standard; and (3) the competent authority of the country of manufacture provides reciprocal treatment for UN standard packagings manufactured in the United States. This authorization is applicable to a UN portable tank approved under an alternative arrangement issued by the competent authority of the country of manufacture if other than the United States.
In addition, when transported to, from, or within the United States, § 171.25(c) requires UN portable tanks used to transport gases to comply with the HMR. UN, and other types of portable tanks transported to, from, or within the United States must also comply with the following requirements prescribed in § 171.25(c)(1) - (c)(4):
- UN portable tanks must conform to the requirements in Special Provisions TP37, TP38, TP44, and TP45 when applicable, and any applicable bulk special provisions assigned to the hazardous material in the § 172.101 Hazardous Materials Table;
- International Maritime Organization (IMO) Type 5 portable tanks must conform to Department of Transportation (DOT) Specification 51 or UN portable tank requirements, unless specifically authorized in the HMR or approved by the Associate Administrator;
- Except as specified in subpart C of part 171 of the HMR, for a material poisonous (toxic) by inhalation, the T Codes specified in Column 13 of the Dangerous Goods List in the IMDG Code may be applied to the transportation of those materials in intermodal (IM), IMO and DOT Specification 51 portable tanks, when these portable tanks are authorized in accordance with the requirements of the HMR;
- No person may offer an IM or UN portable tank containing liquid hazardous materials of Class 3, Packing Group (PG) I or II, or PG III with a flash point less than 100 °F (38 °C); Division 5.1, PG I or II; or Division 6.1, PG I or II, for unloading while it remains on a transport vehicle with the motive power unit attached unless it conforms to the requirements of § 177.834(o) of the HMR.
I hope this information is helpful. Please contact us if we can be of further assistance.
T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division
178.273(b)(7)(ii),178.274(b)(2)(i),178.273(b)(7)(ii),172.102(c)(7)(v),178.274(b)(1),178.274(i), 173.24(d)(2), 173.24(c)(1), 171.25(c) ,171.25(c)(1) - (c)(4), 172.101, 177.834(o)
|§ 177.834||General requirements|