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Interpretation Response #00-0336 ([National Tank Truck Carriers, Inc.] [Mr. John L. Conley])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: National Tank Truck Carriers, Inc.

Individual Name: Mr. John L. Conley

Location State: VA Country: US

View the Interpretation Document

Response text:

January 8, 2001


Mr. John L. Conley                   Ref.  No. 00-0336
Vice President
National Tank Truck Carriers, Inc.
2200 Mill Road
Alexandria, Virginia 22314

Dear Mr. Conley:

This responds to your letter, dated November 29, 2000, concerning cargo tank inspections and tests required by the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180).
Specifically, you ask if an insulated MC 330 or MC 331 cargo tank must be pressure tested in accordance with § 180.407(d).

The answer is yes.  Section 180.407(c) establishes periodic inspection and test requirements for specification cargo tanks.  Generally, an MC 330 or MC 331 specification cargo tank must undergo a visual external inspection each year.  Section 180.407(d) requires a visual internal inspection in place of the visual external inspection for insulated cargo tanks, except for MC 330 and MC 331 cargo tanks.  However, for cargo tanks, including MC 330 and MC 331 cargo tanks, for which an internal visual inspection is precluded, either because the tank has an internal lining or coating or is not equipped with a manhole, § 180.407(d) requires the tank to be pressure tested in accordance with § 180.407(c) and (g).  Consistent with § 180.407(d), the chart in § 180.407(c) indicates that, except for MC 338 cargo tanks, all cargo tanks that are insulated with no manhole or are insulated and lined must be pressure tested annually.

You are correct that, even where insulation precludes a visual external inspection of the tank shell, a visual external inspection of a cargo tank's piping, valves, gaskets, manholes, emergency devices, remote closures, and all major appurtenances and structural attachments must be conducted in accordance with § 180.407(d)(2). The cargo tank must be marked as specified in § 180.415 to indicate successful completion of the visual external inspection.

I hope this information is helpful.  If you have further questions, please do not hesitate to contact this office.



Thomas G. Allan
Senior Transportation Regulations Specialist
Office of Hazardous Materials Standards


Regulation Sections

Section Subject
180.407 Requirements for test and inspection of specification cargo tanks