Long-Term Performance of Ductile Iron Pipes

 Evaluate the impact on pipe performance and life expectancy of the transition (1991) from wall thickness class to pressure class designations in the manufacture and design standards for ductile iron pipes.  Study and compare historical failure rates of ductile iron pipes in a geographically diverse group of water utilities from North America and Australia.  Evaluate reliability and capability of sensors to measure corrosion of ductile iron pipes in the field.  Exhume ductile iron pipes from several geographically diverse water utilities and study in detail the statistical properties of observed corrosion pits. Use these statistical properties of corrosion pits (typically obtained from the inspection of external pipe surface using non-intrusive, non-destructive techniques [NI-NDT]) to develop sampling schemes to assess pipe condition.