I've got a reil burner working and was testing it a few minutes ago in my propane forge, the problem is sometimes you'd hear a puff puff puff noise. I tried adjusting reg pressure for the propane and sometimes going up would help then it would come back then sometimes I'd have to go down with it. I don't have a pressure gauge to know the PSI I was running unfortunately. It heated fine, I was able to heat a 1/4x1" piece of angle iron to forging temp, not welding but forging temp. So it does work but I'm just a bit concerned over the noise.

The burner is a 3/4" with a 1 1/4 to 3/4 reducer, I have a 1/8 brass pipe nipple going through the top of it with a #57 drilled hole as my orifice. This is a venturi burner, it was outside on a lightly windy day in NW Indiana.

When the pressure gets too low it will tend to huff like that, otherwise if the exhaust gets sucked into the burner it will make some some puffing sounds as well. I would highly recommend doing the mig welding tip modification as it will make the burner more stable and efficient.

If you hook up a hose from the faucet to where the propane normally goes you can observe the stream of water coming from the oriface or mig tip and adjust it to center it in the burner pipe. This will help it draw in more air and be stable. A pressure guage is very helpful for tuning.

I think I have it figured out. The insulation was too close around the burner inlet and seemed to be causing an issue. I took a small funnel and used that to expand it some, so far so good. Not forge welding temp but high enough to do any forging I'll need for a while.

You really should be running a regulator even if it runs right. Its just a good idea if for no other reason than to know what you are running in relation to "last time" A one way check valve, also called a an anti flash back is a good safety measure

You really should be running a regulator even if it runs right. Its just a good idea if for no other reason than to know what you are running in relation to "last time" A one way check valve, also called a an anti flash back is a good safety measure

I've got a reg just didn't have a gauge at the time, I went cheap on the reg. After the adapters and purchasing the gauge I could have bought a nice higher end reg with gauge and hose for a few bucks more. Lesson learned. Thanks for the advice though as I'm hooking the gauge up and about to test it again.

Why the antiflash back?  Propane is NOT like acetylene that requires one as it will "exothermically disassociate" even without O2 and is often used with high pressure O2 with a possibility of getting bleed over into the fuel line.

Why? Hmmmmm. I got nuthin'.... I had one in the spare parts bin and used it. Thanks for the info Thomas! :)