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Interpretation Response #15-0190 ([Worthington Industries] [Mr. Steve Gentry])

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

Interpretation Response Details

Response Publish Date:

Company Name: Worthington Industries

Individual Name: Mr. Steve Gentry

Location State: OH Country: US

View the Interpretation Document

Response text:

March 29, 2016

Steve Gentry
Worthington Industries
200 Old Wilson Bridge Road
Columbus, Ohio 43085

Ref. No. 15-0190

Dear Mr. Gentry:

This responds to your September 23, 2015 email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the design and construction of portable tanks intended for the transportation of refrigerated liquefied gases.  Specifically, you describe a proposed vent line for ISO portable tanks.  The manual vent line would be used to discharge lading vapor to the atmosphere in a controlled fashion, prior to the initiation of a pressure relief device.  Your questions are paraphrased and answered as follows:

Q1.  Is the proposed vapor vent line considered a discharge opening as it applies to § 178.277(d)(1)?

A1. No. It is the opinion of this Office that discharge openings are openings which are meant for the loading or unloading of hazardous material.  Therefore, the requirements of § 178.277(d)(1) would not apply to the proposed vapor vent line, unless it is used for the loading or unloading of hazardous material.  

Q2. Do vapor vent lines on portable tanks manufactured to the requirements in            
§ 178.277 require multiple independent shut-off devices?

A2. For ISO portable tanks, § 178.277 only applies to openings which are meant for the loading or unloading of hazardous material.  Therefore, a vapor vent line as described would not require multiple independent shut-off devices.  

Also, please note that the installation of the proposed vent line on an approved portable tank design would constitute a modification of an approved portable tank.  Thus, the portable tank with the proposed manual vent line installed would be subject to the requirements in
§ 178.273(e).

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

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

178.277(d)(1), 178.277, 178.273(e)

Regulation Sections