Special Study--An Analysis of Accident Data from Plastic Pipe Natural Gas Distribution Systems

摘要

The use of plastic materials for pipelines and fittings by the natural gas distribution industry has incrased dramatically since 1965, with the major amount being a polyethylene polymer. The Safety Board completed this study to analyze accident data from both NTSB accident investigations and leak reports submitted by the industry during the year 1975 through 1978 for the purpose of determining whether any significant safety trends could be identified. The study found that there were serious shortcomings with the MTB data collection program which limit the usefulness of the data for ientifying present or potential safety problems that require future investigation is possible. Also, the study found that the main causes of leaks in plastic pipe were breakage from outside forces, exposure to highly localized heat sources, material failures, and construction defects. In every category, the rates of failure or damage in plastic pipe were several times greater than those of equivalent steel pipe failures.