SpudFiles

hello, i want to be able to convince my parents that propane is safe to use in a pressure rated advanced combustion cannon. But i'm getting nowhere fast. can someone tell me how to use a propane meter. I understand that there is a pipe nipple with two ball valves on it and a pressure gauge in the middle section of the pipe nipple. how do i actually regulate how much fuel i need. Because if i were to use a piece of rubber hose with a pipe clamp on the torch head of the propane bottle right as i turn the valve on the propane tank. it would vastly fill the small area inside of the fuel meter.

can someone give me any pointers on how to regulate a fuel meter. using the pressure gauge, for the right amount of propane?

How would i determine the size of the fuel meter nipple? and the PSI to put into the combustion chamber.

Thank You For Your Time

I'm not much of a combustion guy myself but these links might help:
http://www.spudfiles.com/forums/how-to- ... t7234.html

http://www.spudfiles.com/forums/complet ... t4512.html

http://www.spudfiles.com/spud_wiki/index.php/Fuel_meter


BTW, advanced combustions will reach less then half the rating of most pressure rated pipe. So you should be perfectly safe.

Thanxs MrCrowley, would u know what the pressure inside the chamber at the moment of firing.

i mean one time i took a 3lb. sledge hammer and tried to smash a pvc pipe and the hammer rebounded and almost bopped me in the forehead. and i assume a sledge hammer would put more pressure in a single spot. cause i know when a combustion cannon fires it spreads all of the conflagulation throughout the chamber not in a single spot. so it should be safe shouldn't it?

what kind of saftey features does the torch head have so the flame can't go back into the bottle. isn't it a one way valve?

A propane powered combustion cannon creates less than 100 psi. PSI means pound per square inch so imagine putting a 100 pound weight on a 1 square inch spot. So I'm not sure what your generating with your hammer but it's probably not 100 psi.

ok that is good to know, i'm trying to figure out how to use Fuel-Tool Excel program. and it asks for the PSI from the supply tank, by supply tank don't they mean the propane tank. and how much psi is in those little bernzomatic tanks isn't it like 125 PSI?

Yes it wants the tanks pressure. I think they are about 125psi as you said but they differ based on temperature.

thankyou, so how do i actually figure out how well it will work in my cannon as in power wise cause
with a 125 PSI supply pressure it said my fuel meter only needs to be
3.744 inches. is that on both sides of the pressure guage?

how do i find out a fuel mixture?

spudkilla224 wrote: what kind of saftey features does the torch head have so the flame can't go back into the bottle. isn't it a one way valve?

The "safety feature" would be the basic laws of the universe- you can't have combustion without oxygen, and as long as there's a positive pressure inside the bottle, no oxygen is getting in there 8)

Okay I think what you mean is the total volume of the meter should be 3.744 cubic inches. For a 1x mix you fill the meter to 14.7 psi (one atmosphere). A 2x would be double that and so on. But you also have to add another atmosphere of air for every mic eg; 5x mix 5 atms of air. A pvc combustion should never be taken above a 1x mix!

oh ok, gotta love the basic laws of the universe. so how do i start to find my fuel mixture, that's what is confusing me now, like what should be a minimum fuel mixture? and what should be a maximum fuel mixture?

yea i have seen and heard some bad things when people go above a 1X Mix. But should i make my fuel meter bigger than 3.744 cubic inches.

could i get away with a 4.547 inch long fuel meter length with a fuel mixture of 0.051?

or would the 3.744 cubic inches be fine? how would i find the PSI in the chamber for a 3.744 cubic inch meter and a 4.547 cubic inch meter?

1.Fill up meter to 14 psi
2.Dump pressure into chamber
3.Ignite

With a pvc gun never use anything higher than a 1x mix. If you want to go metal thats a whole different conversation.

EDIT- didn't see your other post

I'm not sure what your talking about with the bigger meter. It would make a higher mix becuase of the higher volume. To know when you have 14 psi in the meter use a pressure gauge.

yea i got that concept, it's just me thinking is a smaller fuel meter better than a bigger one? and is 14 PSI safe?

and thankyou for all your help

what does a higher mix mean? does it mean i can have more propane in the meter.

i only want to do a 1X mix to be safe cause it's going to be a Pressure Rated PVC Advanced Combustion.

would i even want a higher mix in an advanced combustion?

Use a regulator like this oneon your propane tank.



When you find how much propane and related meter pressure you need, you can set the regulator to output that pressure. Find a meter size that will allow you a range of say 40 - 60 psi in your meter. This will allow for cold/all weather metering.

You don't need to worry about a mix higher than 1x with a standard PVC advanced combustion. Take a look at my triple thunder cannons in my sig link...watch the shooting video. It shows a noise maker shot but a barrel clamps on very easily and you're ready to go shootin'

It is my opinion that combustion shooting is actually safer than pneumatic because you aren't carrying a pressurized chamber around. Also, the top end psi capability on a really well designed combustion is still under 100 psi and that's if you use a burst disk or really tight fitting ammo in the breach.

I'm a parent, I know how parents are. If you like, I would be glad to converse with your parents by phone or email to discuss. Just PM me if you like...

Thank You, is 40-60 PSI ok to use though? i havn't done propane meters before so if i have like 40 PSI of propane, how many PSI should i expect to see in my combustion chamber when firing? less than a 100 PSI?