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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 #PI-77-0105

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

Interpretation Response Details

Response Publish Date:

Company Name:

Individual Name:

Location State: ME Country: US

View the Interpretation Document

Response text:

April 14, 1977

Mr. W.L. Walls
Gas Field Service
National Fire Protection Association
470 Atlantic Avenue
Boston, MA 02210

Dear Mr. Walls:
This responds to your letter of February 22, 1977, regarding your comments that fire exposure of
aboveground plastic pipe should be covered in 49 CFR 192.375.

The requirement that the aboveground portion of a plastic service line be protected against
“deterioration and external damage” includes protection from fire exposure.  Fire is a form of
external damage and, therefore, it is not necessary that it be specifically mentioned.

I look forward to seeing you at the next TPSSC meeting on May 10, 1977.
Sincerely, SIGNED
Cesar DeLeon Acting Director Office of Pipeline Safety Operations
National Fire Protection Association
470 Atlantic Avenue
Boston, Massachusetts 02210

February 22, 1977

Mr. Cesar DeLeon, Acting Director Office of Pipeline Safety Operations Department of Transportation
2100 Second Street, SW Washington, DC 20590

Ref.: Plastic Pipelines

Dear Cesar,
Notice 77-1, Docket No. OPSO-42 reminded me of a concern of mine. As it does not relate directly to
this Notice, it obviously cannot be considered a response thereto. I really don't know what use can
be made of my concern but, as least, my conscience will be soothed.

When plastic pipe was first proposed (perhaps about 10 years ago) there was pretty universal
agreement that it should not be permitted aboveground. There were a number of reasons for this,
including its lack of resistance to heat from fire.

The National Fuel Gas Code, ANSI Z223.1 - NFPA 54, has maintained its prohibition of aboveground
plastic piping since the matter was initially covered in the 1969 edition, While currently
undergoing extensive revision, I am unaware of any requests to modify the Code in this respect,

In contrast, however, 49CFR 192 has permitted plastic pipe aboveground for some time. 49CFR 192,375
does require that the aboveground portion of a plastic service line be protected against
"deterioration and external damage", The nature of the deteriorating or damaging influences is not

It would seem to me that fire exposure should be one of these influences. Fires in grass, weeds,
leaves, etc. are not uncommon in the vicinity of those risers. I would not be unduly concerned if
failure from fire exposure resulted only in leakage aboveground. We should consider also that
regulators and meters in the same fire area are also often of limited fire resistance. However, if
the design of the casing would permit underground leakage, then I would be concerned substantially.

Has this aspect been considered?
Sincerely, W.L. Walls
Gases Field Service

Regulation Sections

Section Subject
192.375 Service lines: Plastic