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Mapp Gas pressure

Posted: Wed May 27, 2009 6:34 am
by daniel.loechle
Hi, i would like how much pressure my pvc pipes and fittings schooled be able to handle, if i like to use Map gas.

Posted: Wed May 27, 2009 7:04 am
by inonickname
God damn, I'm gonna hang myself soon.

I assume you mean in a combustion process, not as a base propellant gas. The pressure is disputable, but a minimum working pressure in the pipe of at least 200 psi would give an acceptable safety margin.

Posted: Wed May 27, 2009 7:52 am
by daniel.loechle
Y in an combustion process, and its only because im am interested.

Posted: Wed May 27, 2009 9:51 am
by Carlman
Its spelt why

And because thats where the pressure comes from...

Posted: Wed May 27, 2009 12:59 pm
by jimmy101
The peak pressure in a closed chamber for a stoichiometric mixture of MAPP in air is going to be virtually identical to propane in air. There is a larger amount of energy in MAPP than propane (about 10% based on oxygen consumed) but the number of molecules stays the same during combustion for MAPP, whereas it increases with propane. The net result is that the closed chamber peak pressures are, for all practical purposes, identical.

The main difference between MAPP and propane is probably that MAPP burns faster than propane. The faster burn rate of MAPP will give higher peak pressures in an operating gun.

200 PSIG rating sounds about right, that gives you a ~2x safety margin on top of the engineered safety margin. (For all parts except un-rated ones like a cleanout).

Posted: Wed May 27, 2009 2:06 pm
by daniel.loechle
Thanks for that nice reply, 200 psi is about 15 bar. i hope i will be able to find something like that in large dimensions.