Topic: Plastic Pipe

NTSB Recommendation: Determine the extent of the susceptibility to premature brittle-like cracking of older plastic piping that remains in use for gas service nationwide.

PHMSA Action: The Plastic Pipe Database Committee, with representatives from PHMSA, NTSB, American Gas Association, American Public Gas Association, Plastics Pipe Institute, Gas Research Institute, industry and the states, continue to collect data on in-service plastic piping material failures. Data collection will continue until January 2006.

The Plastic Pipe Database Committee (PPDC) continues to evaluate leak data for further outbreaks of slow crack growth failures/leakage in the Nation's distribution pipeline systems. To date as previously indicated, low-ductile inner wall "Aldyl A" and Swanson 3306 materials seem to comprise the bulk. We are monitoring pre-1980 medium density and high density polyethylene materials, but have not seen any indications of concern. Presently, the PPDC Database has gone through five full years of data gathering and has accumulated some 15,000 to 16,000 records. It is anticipated that this organization will continue, and if trends are indicated, all industry and regulatory personnel will be advised..

Latest PHMSA Response: Complete data collection and analysis.

NTSB Status: OAR

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