@mikeinreco - Thank you for those resources. I'm going to take a look at those now. No need to apologize -- we appreciate the help.

@sawmilleng - We have the request in to 7 or 8 utilities who operate large diameter cast iron gas mains. We have good relationships with many of these companies and they have been very willing to help. I also have been contacting the pipeline contractors that perform the replacement work. 80% of the cast iron gas mains in the US are in the northeast. These are typically bell and spigot joint or mechanical joint pipe. There have been extensive programs to replace the cast iron with plastic or steel. Usually its the smaller diameter cast iron mains that have more risk of failure and get replaced first. Larger diameter cast iron mains have much stronger wall thickness.



Thanks for the help so far. I'll report back soon.