SpudFiles

Alright, as far as I know everyone using metered propane has always regulated it but my idea was to design a cannon you don't even need to really meter by getting the amount of fuel needed in the chamber near even with the pressure of comes directly out of a propane bottle when the needle valve fully opened.

I did my math and because of my design, apparently I need 88.7psi of propane into my chamber. Since a regular propane bottle is ~90psi in warm climate can I just skip tryng to meter it altogether and just stick a ball valve after the bottle and let it direct into the chamber?


By my math:

62" barrel, 3" sch40 PVC
42" chamber, 4" sch40 PVC

Vol of fuel for 42" chamber of 4"sch40 PVC needed= 348.2ml
Meter volume will be = 56.9ml
Pressure in BAR on regulator = 6.119 (88.748psi)

Is it going to need ~89 psi into the chamber, can I just let the 90psi from the tank right into it without blowing anything up? It'd be awesome to make some things unecessary and save weight and less parts.

Lert me know what you all think.

That looks about right. Open the propane directly to a 57mL meter, making sure it's vertical and you're feeding gas, not liquid. Then close off the supply from the propane tank, and open a valve to the chamber.

Not sure if propane tanks have an anti-siphon tube.

Mount your propane cylinder upright!