Corrugated stainless steel gas pipe lightning strike fires

The problem is lightning. They first started selling it big time in 1997. By late 1998 they started getting complaints of fires, and by February of 1998 they knew for certain it had to do with lightning. By 2000 they knew for sure they were getting perforation. [Tom shows a perforated CSST sample.] You can see a little hole there. Lightning comes, storm comes by, hits your house, here's the hole — perforates the tube and you've got a blowtorch shooting out of the wall inside your house. Houses tend to burn down — a couple hundred a year. One guy got killed in Texas because of this.

Physical-object teaching unit. Tom shows a perforated piece of CSST tubing from a house fire in Maryland. Used to illustrate (a) the converse-reading of NFPA 780's 3/16" self-protecting threshold, (b) the labor-savings vs. system-cost tradeoff for CSST vs. black iron, and (c) the rhetoric of "we met the standards" as minimum-compliance defense in product liability.

I mentioned the first day, and I passed around examples of traditional black iron pipe — which we're going to talk about a little bit later today — but also passed around some pieces of CSST tubing. I mentioned that the black iron pipe, being about a tenth of an inch thick, if it gets hit by lightning, all you do is melt a little surface, but it doesn't perforate it. The CSST, if it gets hit by lightning, creates a hole. And while cleaning out some trash the other day, I found one I can show you. [Tom produces a piece of damaged CSST tubing.] The problem is settled, but this one has a hole in it. It's easier to see on the back side, but there's one of the holes that was formed by lightning, and burned down a house in Maryland. It's just too thin. They didn't bother to read the NFPA 780 twenty years ago when they were developing the standards for that product.

The opening case of the course. Product brought to market in 1998 by an industry that spent six or seven years checking codes and standards but never considered lightning. By 1999 home fires; by 2001 identified as lightning perforation. Used to set up the entire course's central theme: codes and standards as a historical repository of things that went bad, and the gap between the codes you check and the codes you didn't think to check.

Tom's largest forensic case-load topic: over a hundred houses burned. CSST, approved for residential use in 1997, is a flexible bellows that cuts plumbing time from three days to one but can be perforated by lightning ground currents, turning the wall cavity into a flamethrower. Lightning-strike location within a house is empirically unpredictable even with instrumented test homes in Germany and Florida.

[Tom holds up corrugated stainless steel tubing.] This other one down here is corrugated stainless steel tubing. This is another thing the Gas Association came up with in the 1980s. It wasn't really approved for residential use until 1997. The problem: it's got the yellow coating on a corrugated stainless steel, and if you have lightning come through — if you live in Florida, which is lightning alley, Florida has a higher density of lightning strikes than any other place in the world, surrounded by water that forms clouds that form lightning — you get hit by lightning, and you can perforate this, and now you have a flamethrower in your wall, in the interior of your house.

Substitution from black iron pipe to CSST for residential gas supply; consequent lightning-strike puncture fires. Holman shows a fire-site photograph.

The next one is what's called corrugated stainless steel tubing, CSST. This was an issue because a lot of home contractors wanted to get away from black iron pipe. This is what used to be a threaded pipe — the gas connection to your house. The gas would come in through a black iron pipe. One of the reasons they wanted to get away from it is because the CSST is more flexible. Rather than having a threaded connection with elbows and tees, they could use this material which has some flex to it.