ammosmoke wrote:I think, as a precaution, that you should attach the popoff valve to an elbow that faces backwards, away from your head and hair.

This is another one of those paranoid things that isn't really required, but sure can't hurt.... Good idea, ammo smoke. I'll do that.

Please tell me, where did you get the gauge and how to you put it in?

You can get pressure gauges at almost any hardware store (near the air compressor tools and accessories) or online.

To install one, drill out a hole in the PVC just smaller than the threads on the gauge, where a pipe and ...

Pop off valves on a flamethrower are just plain dangerous. You don't want anything coming out of a flamethrower while in usage except at the nozzles

OK, so without the pop-off (or with one with a much higher trigger pressure, such as 200psi), can you spot any flaws in my design?

I really ...

general lack of common sense. the back flash/regulator/pop-off valve bit showed some of it. As did the fuel level gauge made of glass.

While you may view this as lack of common sense, I think most would view it as paranoia. The backflash (check) valves, regulator, and pop-off are not required, I ...

um, may i point out that your tank drawing are not pressure rated? you say they are, but thats more un-pressure rated than a panda. poor things cant handle stress.... :lol:

It's just a diagram done in Visio, drawn mostly by hand. I say in the instructions to use NOTHING but pressure-rated NSF-PW ...

Well, propane is only about 70-80 psi, so having that valve shouldn't be a problem. Backflash probably wouldn't do anything, but then again, it may render your flamethrower useless due to the small size of the nozzle. So, as long as the valve only pops when you have backflash, then your good ...

Benstern,

The 125-psi pop-off should never need to open. With a propane regulator (which I know is not required but allows better control over pressure), the pressure in the tank should never go above 100psi. Use a 150psi pop-off instead if you're worried about that happening.

I know that since ...

Here's the parts list, as promised:

Tank - ALL PVC MUST BE PRESSURE RATED NSF-PW!!!

4x 4" Sch40 90-degree NSF-PW
5ft 4" sch40 NSF-PW PVC pipe

4x brass 1/2" 90 degree, male threads on one side, femal threads on the other
7x brass 1/2" close nipple
1x brass 1/2" 4-way T
1x 1/2" - 1/4" reducer ...

Here's a higher resolution diagram with more labels.

By the way, the plastic pipe on the "gun" part is just "furniture", so any kind of pipe will do (I use ABS cause I have a lot of it laying around). The "barrel" and "pilot" tubes are 1/4".

Pete,

Thanks. Yeah, they're done in visio.

I use 1/2" for the quick connect, ball valve, and T, and 1/4" for everything else on the gun. The actual tip of the "barrel" is a hose barb. The propane pilot light tip is an end cap with a teeny hole drilled for the pilot light.

I have not yet played ...

This is a rough sketch of my design for a flame thrower. It's made of PVC and brass parts and fittings, and will be pressurized with propane.

First, a disclaimer. This isn’t the normal legal mumbo jumbo, so please read it. The whole thing.

This drawing and parts list is offered for educational ...