Pipeline Safety Interpretation PI-77-0105

Page 1PI-77-0105 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#

Page 2National 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 addressed, 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#