Jump to content
I Forge Iron

Gas forge orifices


Iron Falcon 72

Recommended Posts

I have a two burner forge built by a fairly well-known blacksmith apparently like the one he uses. It's a piece of 12" round pipe with top-mount burners. I'll post pictures this evening.

When lit one of the burners (the one at the "back of the forge") was running green, the other nicely blue. It also tended to huff. One time it huffed, flashed back and exposed a leak in one of the pipe fitting joints. I took it apart and discovered that because of the geometry of the welded-in burners the pipe fittings had to be overtightened to align properly causing stripped threads and leaks. I rebuilt it (welding the fittings which were too close together to thread together), no more leaks and the orifices still lineup with the bells.

In the process of rebuilding, apparently, I reversed the orifices so the old back one is now in front. Now the front flame is green. Using a sparkplug gap gauge I discovered that the burner that has a nice blue flame is .025 and the green one is .028. Is that difference enough to cause the green flame?

Link to comment
Share on other sites

Here are some pictures. The orifices appear to be 1/4" brass plugs that may have been drilled out. They are even with the end of the bells as directed by the builder. The supply side is 1/4" black pipe, the bells are 2 1/8" and the mixing tubes/burners are 1" BP. The T joint was the leak source. I just welded the corners to the T.

There is only one supply from the tank to the shutoff valve. Unfortunately, adjusting one orifce position adjusts both. There aren't any constrictions in the burner tubes.

Thanks

12133.attach

12134.attach

12135.attach

12136.attach

12137.attach

Link to comment
Share on other sites

I'm not sure where to start. I've never seen burners quite like those before. They're linear inducers like Ron Reil's EZ though not very well designed.

Aligning the jets looks to be nearly impossible, the transition from the intake bell to the throat is abrupt which will cause turbulence and the 90* bends are causing back pressure.

My 1" burners use 0.045" mig tips for the gas jets which will supply 4x the propane at any given pressure as a 0.023" orifice.

Heck, one 3/4" burner should do the trick for you if my guesstimate of the depth of the chamber is right. It's a half cylinder measuring 8.5" wide, 5" high and about 9" deep or there abouts right? If so that's 255 cu/in and well within the volume a 3/4" burner will bring to welding heat.

I suggest you check out Larry Zoeller's side arm or Z burners or if you're handy with tools make one of my "T" burners or even a Reil EZ. Any of them will heat your forge properly. Trouble shooting the ones you have now is going to be more work than building a new one.

Frosty

Link to comment
Share on other sites

It's a half cylinder measuring 8.5" wide, 5" high and about 9" deep or there abouts right? If so that's 255 cu/in and well within the volume a 3/4" burner will bring to welding heat.

I suggest you check out Larry Zoeller's side arm or Z burners or if you're handy with tools make one of my "T" burners or even a Reil EZ. Any of them will heat your forge properly. Trouble shooting the ones you have now is going to be more work than building a new one.

Frosty


I was afraid someone was going to say that. I've since found out that some of the local guys are using one like it and they say they can probably tune it. I'll use it as is for awhile and then build my own. I have a nice piece of pipe that should work well.

If I'd done a little research before I bought I probably wouldn't have gotten this one. But, the good thing is it got me off my .... and got me going.
Link to comment
Share on other sites

  • 3 weeks later...

PLEASE READ THIS!
follow this link
Teflon offgas studies | Environmental Working Group

I am a retired plumber. The first thing that caught my attention when I saw your pics was the white bands around the fittings. I have a tendency to drag to much science into my comments, and in the case of atmospheric burners my pet peave is the venturi or lack thereof... but the danger in your installation is the presence of Teflon tape on the furnace fittings. 396

Link to comment
Share on other sites

That's significantly frightening Courtiron.

Thanks for bringing it to my attention, I'll be passing the word for sure.

The really ironic thing here is it's completely unnecessary on the burners past the jet. Putting T tape on the burner tube does no good and now I see it's serious health risk.

Falcon Buddy, get the T tape out of there!

Thanks Frosty.

Link to comment
Share on other sites

Yes. He had no ideas. Even though the only variable left is the orifice size difference he doesn't think it could cause it.

The orifices are just 1/4 pipe thread plugs with a hole drilled in it. I have some needle valves on order. If that doesn't work I'll just drill out a new orifice.

Thanks for the info on the teflon tape. I'll change it out when I start putting this back together.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...