Performance of Plastic Pipes and Pipe Gaskets In Hydrocarbon Contamination: Field Experience and Laboratory Studies

摘要

Water utilities were surveyed and laboratory studies were undertaken to determine the limits of hydrocarbon contamination in which polyvinyl chloride (PVC) and polyethylene (PE) pipes and various types of pipe gaskets can be used successfully, without customer complaints or laboratory data exceeding U.S. EPA MCLs. Permeation incidents were reported at a frequency of one per 14,000 miles of mains and one per 1,000,000 PE/PVC service connections. Successful use of water mains in contaminated areas was reported at a frequency of one per 1,800 miles of mains and one per 2,500,000 plastic service connections. Gasoline was the most frequently reported contaminant. Laboratory studies showed that PVC pipe is highly resistant to gasoline and water saturated with gasoline. PVC pipe is also resistant to water solutions of benzene, toluene, and TCE but the most extreme levels of environmental contamination. The rate of progress of the moving front in PVC pipes exposed to pure benzene, toluene, and TCE is a function of the square root of time, whereas it is linear with time for aqueous solutions of those solvents. A method is described for predicting the resistance of PVC pipe to permeation based on visualization of the progress of the moving front during the first 24 hours of exposure to a contaminant.