Pipe Materials in Calgary Presentation Slide #24

We find it, however, well worth it -- the break rates are a fraction of those on any other metallic pipe - just over a tenth. So far, of 600 km, we've never replaced any for corrosion-related causes, and only a few hundred metres for any reason.
You'll note that I've just lumped together PDI and DI together on one line of this chart. In 1978, Jim Bouck and other Calgary Engineers attended this same conference and described their problems and their YDI approach, and said that PDI had no discernably different break rate from bare DI. That got them a lot of hot replies and raised voices. DIPRA, the ductile iron pipe research association, was not pleased.