Full disclosure, the last time I studied chemistry was 20 years ago, and I was not a particularly good student, so take this with a heaping helping of NaCl.
It isn’t the direct reaction of Drano + PVC that causes the issue. Rather, it’s the heat given off from the reaction of the clog and the lye. Apparently it’s significant enough to be an issue. I tried looking up how much heat might be released by the reaction, but I went crosseyed reading the formula, so someone else will have to do the math on that one.
Also, I know you said caustic material doesn’t react with metal, but Google doubts you on that front, for whatever that’s worth. In fact, zinc is specifically called out as a metal with which sodium hydroxide reacts pretty strongly, which is important because many water lines are steel galvanized with, you guessed it, zinc.
That does not make sense. PVC drains don’t react to caustics, nor do metals.
Full disclosure, the last time I studied chemistry was 20 years ago, and I was not a particularly good student, so take this with a heaping helping of NaCl.
It isn’t the direct reaction of Drano + PVC that causes the issue. Rather, it’s the heat given off from the reaction of the clog and the lye. Apparently it’s significant enough to be an issue. I tried looking up how much heat might be released by the reaction, but I went crosseyed reading the formula, so someone else will have to do the math on that one.
Also, I know you said caustic material doesn’t react with metal, but Google doubts you on that front, for whatever that’s worth. In fact, zinc is specifically called out as a metal with which sodium hydroxide reacts pretty strongly, which is important because many water lines are steel galvanized with, you guessed it, zinc.