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

Interpretation Response #17-0030 ([Quantum Fuel Systems] [Mr. Tae Kim])

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

Interpretation Response Details

Response Publish Date:

Company Name: Quantum Fuel Systems

Individual Name: Mr. Tae Kim

Location State: CA Country: US

View the Interpretation Document

Response text:

June 19, 2017

Tae Kim
Design Release Engineer
Quantum Fuel Systems
25242 Artic Ocean Drive
Lake Forest, CA 92630

Reference No. 17-0030

Dear Ms. Kim:

This letter is in response to your February 24, 2017, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the general requirements for shipment of compressed gases and other hazardous materials in cylinders, United Nations pressure receptacles, and spherical pressure vessels. You include a diagram of a manifolded cylinder system and specifically seek confirmation of your understanding that the regulations in § 173.301(g) would allow the quarter turn valve or shutoff valve to remain in the open position if an air operated valve (AOV) is closed while the cylinders are manifolded in transportation.

Your understanding is not correct. According to § 173.301(g), each cylinder must be equipped with an individual shutoff valve that must be tightly closed while in transit, except cylinders containing a Division 2.2 material. While your original email did not specify the primary material being filled inside the cylinders, you explained in a subsequent email and phone conversation with a member of my staff that it would be either a Division 2.1 or Division 2.2 material. The individual shutoff valve for cylinders filled with a Division 2.1 material cannot remain open while in transit even if an AOV is installed. However, cylinders filled with a Division 2.2 material are not subject to the individual shutoff valve requirements and can remain in the open position while in transit.

In addition, the HMR do not prohibit the use of an AOV installed on manifolded cylinder systems. However, in order to use an AOV while transporting a Division 2.1 material in the manner you describe, you must submit an application for a Special Permit.

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



Dirk Der Kinderen
Chief, Standards Development Branch
Standards and Rulemaking Division


Regulation Sections

Section Subject
173.301 General requirements for shipment of compressed gases and other hazardous materials in cylinders, UN pressure receptacles and spherical pressure vessels