Interpretation Response #22-0028
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: DOT Training Solutions
Individual Name: Mr. Randy Decker
Location State: KS Country: US
View the Interpretation Document
Response text:
January 24, 2023
Mr. Randy Decker
Safety Consultant
DOT Training Solutions
P.O. Box 25311
Overland Park, KS 66225
Reference No. 22-0028
Dear Mr. Decker:
This letter is in response to your March 17, 2022, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the testing and inspection requirements for multi-compartment Department of Transportation (DOT) specification cargo tanks. In your email, you state that §§ 180.407(g)(1)(vi) and 180.407(h)(1) of the HMR require that each cargo tank of a multi-tank cargo tank motor vehicle be pressure-tested and leakage-tested respectively, with the adjacent cargo tanks empty and at atmospheric pressure. Furthermore, you ask whether a void at atmospheric pressure between double bulkheads—as described in your email—may be considered an adjacent compartment for the purposes of pressure and leakage testing under § 180.407.
The answer is no. Sections 180.407(g)(1)(vi) and (h)(1) both state that "each cargo tank of a multi-tank cargo tank motor vehicle must be tested with the adjacent cargo tanks empty and at atmospheric pressure." Under § 178.345-1(c), the HMR define a "void" as "the space between tank heads or bulkheads and a connecting structure." Therefore, a "void" does not meet the definition of a cargo tank.
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division
178.345-1(c), 180.407, 180.407(g)(1)(vi), 180.407(h)(1)