6% of chemical refinery pipes mislabeled (PMI)

In some chemical plants, a chemical refinery, I've seen data of different steel pipes where they've gone in and done a very careful positive materials identification, and 6% of all the pipes are mislabeled as to what type of steel they are. You say, well, it's no big deal, it's all steel. Well, not necessarily. I was involved 25 years ago in a case up in the tar sands in Canada, where someone was supposed to repair a pipe. They had cut out a little piece — they were putting in an 18-inch piece of 6-inch steel pipe, welding it back in. They had to open it up to get in and clean out the pipe, because a bunch of coke deposits had formed inside the pipe and they had to clean it out — it was getting hardening of the arteries and couldn't get the oil to flow through anymore. So they cut out a piece, went in with their reaming tools, cleaned it out, and welded a piece back in.