Interpretation Response #02-0140 ([Carlton W. Hendrix, Jr])

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

Interpretation Response Details

Response Publish Date: 07/01/2002

Company Name:

Individual Name: Carlton W. Hendrix, Jr

Location State: GA Country: US

View the Interpretation Document

Response text:

Jul 1, 2002

Mr. Carlton W. Hendrix, Jr.                   Reference No. 02-0140

230 Ellenwood Drive

Canton, GA 30115-8276

Dear Mr. Hendrix:

This is in response to your May 1, 2002 letter requesting interpretation of the Hazardous Materials Regulations (HMR; 49 CFR Parts 100-185) applicable to open valves on cargo tanks.  Specifically, you question the practice of some transporters of non-flammable, compressed gases leaving a valve, located between the pump and the cargo tank's hose connection, slightly open on transports with a capacity greater than 3500 water gallons.  Per your letter, the purpose of this practice is to allow any excess pressure that builds up in the 2 inch "wet" hose to return to the cargo tank through the bypass feature of the internal valve.

As provided in § 177.840(g) each liquid discharge valve on a cargo tank motor vehicle, other than an engine fuel line valve, must be closed during transportation except during loading and unloading.  This means each discharge valve in a liquid discharge system must be closed during transportation. This requirement does not pertain to any intermediate isolation valves that may be present in a liquid discharge system.  The main internal valve and delivery hose end valve must be closed while in transport.  You are not required to close any other valves in the system.

I hope this information is helpful.  If we can be of further assistance, do not hesitate to contact us.

Sincerely,

Delmer F. Billings

Chief, Standards Development

Office of Hazardous Materials Standards

177.840

Regulation Sections