With regards to the instability of Acetylene beyond 15psi-
I was reading about that in a trades handbook I have while killing time today. The book made it sound very much like the CYLINDER pressure is not greater than 15 PSI. Therefore, I ask: No matter how high you turn the regulator or torch, how can output pressure possibly exceed cylinder pressure? Or did I misread something?
You're correct about the rough max pressure on an Acetylene cylinder being approx. 15 PSI. The reason the pressure is so low (and the reason things get unstable around that point) is that Acetylene isn't stored under pressure; it's stored in
solution in Acetone. When you crank up the pressure, you also crank up the rate of extraction; when you are trying to pull off the tank at a higher rate than the boiling point in the tank (think pulling the Co2 off a two liter bottle that's full), you start pulling the Acetone out of the tank as well (hence things getting unstable).
That's why you always need to match your torch to the size Acetylene tank you are going to use; the Acetylene
"boil" has to be under the point where you start pulling out the carrier solution (Acetone).
I may have missed some exceedingly fine details, but I'm fairly confident that I've dredged up the overall details.
If anyone out there can find fault, please do so
WITH FOOTNOTES; that way we can bring facts to the table.
Pat
