Flamethrower Plans. Critique?

[mik3v]

Okay so my friend and i are making a flame thrower.
We are having a pvc tank pressurized with an air compressor. Gasoline is going to be inside the fuel tank too.
We have pressure valves and other precautions.
The gun itself is made of copper fittings and pieces.

We have a question about the pvc pipe we got at lowes for our fuel tank that will be pressurized. it says this on it:
"4'' Silver-Line Cellular Core PVC-DWV PIPE ipe sch 40 series [astm F-891-07 NSF-dwv I/O] OK 6B SL-CM -- NON-PRESSURE --- 03/20/09 14,00"

This safe? ive built spud cannons before and always get the pvc thats sch 40 and nsf. but this says non-pressure. that mean anything?

[hi]

"Is this safe?"- no

there is nothing safe about shooting gasoline out of a pressurized line and lighting it on fire.

[daberno123]

but this says non-pressure. that mean anything?

Yes, it means you shouldn't pressurize it.

Always use pipe that has a pressure rating printed on it. Schedule 40 by itself means nothing, it only designates how thick the wall is.

[c11man]

gasoline plus compressed air is big nono

pretty much this entire desigh is unsafe.

This safe? ive built spud cannons before and always get the pvc thats sch 40 and nsf. but this says non-pressure. that mean anything?

all i have to say is duh. non pressure means NOT FOR PRESSURE!!! THINK IT THROUGH.

compressed air has alot more oxygen in it over normal air so your tank will go boom. not just a little boom. the kind of boom heard half a mile away and sends 6inch pvc splinters into your body.

if you insist on making a flamethrower at least use propane as a pressure source


also expect this topic to be locked......

[mik3v]

then what the heck? it says nsf on the pipe. they didnt have any that didnt say "non-pressure"

[mik3v]

"Is this safe?"- no

there is nothing safe about shooting gasoline out of a pressurized line and lighting it on fire.

oh you are very intelligent. thanks so much for your wonderful input.

[c11man]

ok i will step you through it

4'' Silver-Line Cellular Core PVC-DWV PIPE ipe sch 40 series [astm F-891-07 NSF-dwv I/O] OK 6B SL-CM -- NON-PRESSURE --- 03/20/09 14,00"

Cellular core-the center of the pipe is FOAM!
DWV pipe- this means that the pipe is intended for use in non pressureised aplications like drains, waste removal, and vents
NSF-Dwv- again same thing
NONPRESSURE- again not meant for applilactions that have pressure

[mik3v]

oh. i assumed it was pressure rated since it said nsf.

what would the pressure stuff say?

[c11man]

nsf-pw along with a specific pressure

[Ragnarok]

It seems like you've got this week's sardonic wit brigade.
No offence guys, but a little less sarcasm (particularly on the repeat points) and a little more useful input would benefit the forum.

Also, c11man - you seem to have a habit of assuming the worst possible scenario to be the probable scenario. Yes, there's a chance it could combust - that does not mean that "[his] tank will go boom". Could and will are very different.
I wouldn't recommend mixing compressed air, fuel, unrated PVC and ignition sources either, but I'm not going to say it's certain that explosions are going to follow.

~~~~~

mik3v. My best advice to you is Google for Roland Tower's creation (But I'm not going to give a direct link, sorry). It's got a decent set of build instructions with it.

Still, like suggested, propane (preferably regulated) is a better pressure source for a flamethrower than compressed air. Indeed, military flamethrowers will use either pure nitrogen or propane to reduce the risks of ignition. Nothing with oxygen in it.

Good tough pipe is also a must.

[hi]

"Is this safe?"- no

there is nothing safe about shooting gasoline out of a pressurized line and lighting it on fire.

oh you are very intelligent. thanks so much for your wonderful input.

NSF- National Sanitary Foundation. That means that if you run water through it its OK to drink it.

Look kid, you are not being real smart. Quite frankly your being an idiot. Flame throwers are really cool, but you are building something that could very easily end your life. Building a thing out of plastic pipe that shoots a potato a couple hundred feet is one thing, but you are talking about building something that has the potential to cause a very large fire and cause you and others near by a lot of harm.

I once thought about building one, but then I realized that its a very foolish thing to do and i have no interest in building one anymore. I have learned that when you get the mentality that nothing bad is going to happen, you are going to get hurt.

[Moonbogg]

If you do this, use an inert welding gas as the pressurizer. Maybe even use c02 as your pressurizer. That way it can't explode inside your main tank. Don't use compressed air though as has been mentioned before.

[boom_o_matic_2.0]

ok I"m suprised a moderator hasnt brought down the BAN-HAMMER on this thread by now. lol. plus too gasoline would weaken the pvc and make it rubbery. PVC is soluble in gasoline. not only is there a risk of combustion, there is just a risk of it popping like a big flamable balloon. if you wanna do it, use a different pressure source AND different fuel. the whole design is a flop. sorry dude

[c11man]

It seems like you've got this week's sardonic wit brigade.
No offence guys, but a little less sarcasm (particularly on the repeat points) and a little more useful input would benefit the forum.

Also, c11man - you seem to have a habit of assuming the worst possible scenario to be the probable scenario. Yes, there's a chance it could combust - that does not mean that "[his] tank will go boom". Could and will are very different.
I wouldn't recommend mixing compressed air, fuel, unrated PVC and ignition sources either, but I'm not going to say it's certain that explosions are going to follow.

~~~~~

mik3v. My best advice to you is Google for Roland Tower's creation (But I'm not going to give a direct link, sorry). It's got a decent set of build instructions with it.

Still, like suggested, propane (preferably regulated) is a better pressure source for a flamethrower than compressed air. Indeed, military flamethrowers will use either pure nitrogen or propane to reduce the risks of ignition. Nothing with oxygen in it.

Good tough pipe is also a must.

sorry to assume the worst. i just want him to realize that he needs no take EVERY precaution and have a very solid safe design for this to operate safley. its not for sure that it will explode but its just like why hybrid pvc cannons are not good. it is not for sure that it will go wrong but there is always the chance that it will

[Technician1002]

It seems like you've got this week's sardonic wit brigade.
No offence guys, but a little less sarcasm (particularly on the repeat points) and a little more useful input would benefit the forum.

Also, c11man - you seem to have a habit of assuming the worst possible scenario to be the probable scenario. Yes, there's a chance it could combust - that does not mean that "[his] tank will go boom". Could and will are very different.
I wouldn't recommend mixing compressed air, fuel, unrated PVC and ignition sources either, but I'm not going to say it's certain that explosions are going to follow.

~~~~~

mik3v. My best advice to you is Google for Roland Tower's creation (But I'm not going to give a direct link, sorry). It's got a decent set of build instructions with it.

Still, like suggested, propane (preferably regulated) is a better pressure source for a flamethrower than compressed air. Indeed, military flamethrowers will use either pure nitrogen or propane to reduce the risks of ignition. Nothing with oxygen in it.

Good tough pipe is also a must.

sorry to assume the worst. i just want him to realize that he needs no take EVERY precaution and have a very solid safe design for this to operate safely. its not for sure that it will explode but its just like why hybrid pvc cannons are not good. it is not for sure that it will go wrong but there is always the chance that it will

Since this hasn't been banned, locked, and members expelled i'll make a safety note. Add a drip bump on the bottom near the muzzle so if it (when it) dribbles, you don't get flames running back to you under the barrel. Have something to dribble flaming liquid off the barrel so it can't run back.