USA Banner

Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #06-0260 ([D.J.'s Truck Repair, Inc.] [Mr. David Jones])

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

Interpretation Response Details

Response Publish Date:

Company Name: D.J.'s Truck Repair, Inc.

Individual Name: Mr. David Jones

Location State: IL Country: US

View the Interpretation Document

Response text:

February 25, 2008

Mr. David Jones


D.J."s Truck Repair, Inc.

7202 Herter Industrial Drive

Godfrey, IL 62035

Ref. No. 06-0260

Dear Mr. Jones:

This responds to your letter requesting clarification of the rejection criteria when performing a leakage test on a cargo tank motor vehicle that is used primarily for the transportation of compressed gases, such as anhydrous ammonia and propane, under the Hazardous materials Regulations (HMR; 49 CFR Parts 171-180). Specifically, you ask if the back flow check valve installed on a product inlet opening (spray fill line) is considered a self-closing stop valve and, therefore, must be leak tight when leak tested under § 180.407(h). You state that when the liquid valve is opened while testing the product piping system under pressure, the back flow check valve will often leak. I apologize for the delay in responding and hope it has not caused any inconvenience.

Under § 178.337-8(a)(3), each product inlet opening must be fitted with a back flow check valve or an internal self-closing stop valve located inside the cargo tank or inside a welded nozzle that is an integral part of the cargo tank. Under the leakage test requirements in § 180.407(h), only internal or external self-closing stop valves and product piping and delivery hoses are required to be tested for leak tightness under pressure. Therefore, a back flow check valve is not required to be leak tight and would need not be considered under the rejection criteria under § 180.407(h)(3).

I trust this satisfies your inquiry. Please contact us if we can be of further assistance.



Hattie L. Mitchell

Chief, Regulatory Review and Reinvention

Office of Hazardous Materials Standards

180.407(h)(3), 178.337-8(a)(4)

Regulation Sections

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