under slab PVC glycol piping

Where are you located? In the Houston area most of the foundation repair companies will also do under slab excavation to fix piping.

You might get a plumbing contractor to do a boroscope inspection to make sure the problem really needs under slap excavation to do the repair.

Thanks

This is in a number of locations. They are in food warehouse freezer. The scope crossed my mind but I was trying to keep away from tearing it up. The pipe actually sits in fill below the slab to prevent the grade from freezing.

There was some discussion about this about a month ago right here:

http://cr4.globalspec.com/thread/18876#comment198316

Mike

I successfully pulled a half inch water hose through a corroded 3/4 inch leaking steel pipe, (actually two pipes, hot AND cold) allowing an upstairs bathroom to be put back into service in less than a day. It was a tricky process though...involving vacuuming through a string, then attaching the string to a cord, and then wrapping steel wool around the sash cord to clean the rust. (and a bottle of diswashing soap!) What is in there now is a clear reinforced plastic hose which I have been told meets code. That was about 40 feet of steel pipe that didn't need to be removed, repaired, or bypassed, and there was no damage to the walls or woodwork. I was fortunate that the elbows in the system were nice big old fashioned volutes and there were only two of them!

Do you think this technique might be a useful in your job?

that sounds like a great idea. BUt unfortunatly it will not work in my application. There may be 100s if not 1000s of feet.