maatoug - I've never experienced the issues you describe with steel pipe joints, that is unless you've suffered a serious skilled trades issue - as in having unskilled people and NOT pipefitters performing the work. What I have seen with plastic piping in chilled water service is a catastrophic failure of a plastic line, because someone (I suspect an insulator) stepped on it between supports. It's amazing how much water will flow from each end of a broken 2" line. Plus, it was in a functioning courthouse - including a state supreme court judge's chambers. The water damage was extensive, and the repair costs were spectacular...
Should that guy have stepped on the line? No, he should NOT have. But he did - and it was a bad, bad day indeed. Mechanical strength matters.