Closed in Transportation
Pipeline and Hazardous Materials Safety Administration · Oct 12, 2006 · Reference No. 06-0185
Interprets: 49 CFR § 177.834
Reggie’s quick take
A company that ships propane asked whether a fully automatic internal valve on its bobtail cargo tanks counts as "closed in transportation" under § 177.834(j). The agency said yes, if the pump is not running and the slot in the valve's visual indicator sits horizontally. The valve is a RegO Products "Flomatic" that opens when the pump pushes on a piston and closes when the pump shuts off.
Written by AI (Claude) on Oct 22, 2026. Robots make mistakes and leave things out, so the letter below is what counts. Not legal advice.
This is in response to your July 31, 2006 letter and August 16, 2006 telephone conversation with a member of my staff asking if a RegO Products "Flomatic" fully automatic internal valve installed on your company's bobtail cargo tanks is considered closed in transportation under § 177.834(j) of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180).
You state the cargo tanks are in propane delivery service and when the pump is operating it applies pressure to a piston that opens the internal valve, that this valve closes when the pump is turned off, and the visual indicator that shows when the valve is open or closed is located on its top flange. You also state this internal valve eliminates the need to close a separate actuator switch at another location on the cargo tank truck and to operate the internal valve this separate switch must be open.
Based on the information you provided, the answer is yes the valve is considered closed in accordance with § 177.834(j) of the HMR when the cargo tank pump is not in operation and the slot in the visual indicator is in a horizontal position.
A letter of interpretation applies the regulations to the facts the requester described. It isn’t a regulation and isn’t legal advice. The agency’s copy.