Interpretation Response #17-0122

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

Interpretation Response Details

Response Publish Date: 07/12/2018

Company Name: HazMat Resources, Inc.

Individual Name: Mr. Danny Shelton

Location State: TX Country: US

View the Interpretation Document

Response text:

July 12, 2018

Mr. Danny Shelton
President
HazMat Resources, Inc.
124 Rainbow Drive, Suite 2471
Livingston, TX 77399-1024

Reference No. 17-0122

Dear Mr. Shelton:

This letter is in response to your November 1, 2017, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the marking and inspection of U.S. Department of Transportation specification cargo tank motor vehicles (CTMV). We have paraphrased and answered your questions as follows:

Q1.   You ask if the manufactured thickness must be marked on a nameplate when the manufacturer builds in a corrosion allowance.

A1.   The answer is yes. As prescribed in § 178.345-14(b)(13) and (14), the manufactured thickness is required to be marked on a CTMV nameplate when additional thickness is provided by the manufacturer for corrosion allowance.

Q2.   You note that a CTMV is not required to have a vacuum breaker if its tank is designed to be loaded by vacuum or built to withstand a full vacuum.  Therefore, you ask how a registered inspector is to determine if the CTMV meets the specification requirement if there is no indication on the nameplate that its tank is designed to be loaded by vacuum or built to withstand a full vacuum.

A2.  Section § 178.345-14(b) of the HMR prescribes the information required to be marked on a cargo tank's nameplate, in addition to any applicable information required by the ASME Code. Paragraph UG-116(a)(4) in Section VIII of the 2015 ASME Code requires the maximum allowable working pressure (MAWP) to be marked on the nameplate as "maximum allowable working pressure (internal or external)," when specified as a design condition. Consequently, if the marked MAWP (external) is below 1 atmosphere (14.7 psi), it does not meet the exemption requirements of § 178.347-4(b) and vacuum relief devices (e.g., breaker) are required.

I hope this information is helpful. Please contact us if we can be of further assistance.

Sincerely,

Shane C. Kelley
Director,
Standards and Rulemaking Division
Office of Hazardous Materials Standards

178.345-14(b)(13) and (14), 178.345-14(b), 178.347-4(b)

Regulation Sections