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seen lots of it. tends to affect the lines that don't see a lot of water. i see more of it on roof drains, deck and planter drains. along with vents. even fixtures with little use.
the theory has been that the rust forms on the inside of the line. drys out and then more rust forms creating pressure on the pipe due to expansion of the rust buildup. when the line stays damp, the rust never drys out and doesn't go through the same expansion as a wet then dry then wet line.
did a big hotel in the early 90's. all the same brand of no hub used on the waste, vent and storm and planter drains. hotel owner calls me up a few years ago and ask me why his planter and roof drains are cracking. i explained it pretty much the same way. all the same pipe installed all the same time.
when i see it, the cracks tend to be split open from 1/8''- 1/4''+. amazing as the pipe doesn't have any elasticity to it, yet springs open.
I'm looking at the last pic and the pipe looks like it was chewed off by a big junk yard dog not cut properly by a plumber. Or maybe it broke when you removed it.
IF that is how you found it that big chunk hanging out on the right would take all the pressure with the pipe in a riser concentrating the force applied at that point and if there was a slight crack there it would chase up the pipe all the way to the other end be it 14" or 10 feet as the pipe settled over time. No doubt there was less than adequate support which would contribute to the problem. That looks like a piece of Tyler No-Hub pipe. Is the fitting Tyler also or Charlotte. Looks like the latter to me.
OTOH I can remember getting a whole skid of bad Tyler 2" which had casting flaws. The pipe was not spun properly when cast and had a lamination with a ripple like appearance much like this. It was not obvious at first glance during the install because it had been coated over with the bitumastic but during testing it showed up. We replaced about 200 feet of vent and drains sending it all back to Tyler for credit. That was about 20 years ago.
"It's a table saw, do you know where your fingers are?" Bob D. 2006