Gas Forge Build 2: Gas System

After considering a few different burner designs, I opted to hybrid something between the Ron Reil design and Michael Porter's design. I wanted basic parts in the plumbing section, and I wanted a straight, fast acceleration.

The gas system is from the LPG tank to the nozzle and consists of some components I've assembled from McMaster-Carr, Home Depot and Amazon.



Moving from the tank towards the burner, first we have the regulator. The regulator is needed to reduce the pressure from inside of the LPG tank, from say 150 psi to a usable pressure like 5 or 10 psi.
 
 
My regulator is a 0-30 psi adjustable, although it doesn't have to be adjustable, as a 10 psi fixed pressure regulator would work. You can then use the ball valves to control gas rate. The regulator screws into the tank with an ACME connection. It's important to recognize there are two connections types: ACME (outside threads on the tank valve) shown in photo and P.O.L. "Prest-O-Lite" which has inside left-hand threads on the tank valve.



From the regulator we have a 1/4" NPT tee that goes off to the pressure gauge. As the tee is a female/female/female, I needed a 1/4" NPT nipple to connect the gas hose to the accelerator assembly.  The hose screws into the burners with a 1/4" female NPT connection.


A single accelerator assembly consists of the following parts fitting together with gas rated pipe dope.



1 - 50785K152 Medium-Pressure Brass Threaded Pipe Fitting, 1/4 Pipe Size X 7/8" Close Nipple
2 - 4205166 Ball Valve, 1/4" F- 1/4"F, WOG 600, 150 WSP, Lead Free, Forged. ProFitter
3 - 4429K411 Brass Threaded Pipe Fitting, 1/4 M to 1/8 F Reducing Bushing
4 - 4568K115 Standard-Wall Brass Threaded Pipe Nipple, 1/8 Pipe Size X 3" Length
5 - A55 6240 Adapter, 1/4" OD to Flare 1/4" Compression with Gasket 
6 - KH710 Lincoln MIG welding contact tip, 0.035". 



7 - 9151K12    Nickel-Plated Brass Threaded Pipe Fitting, 1/4" Pipe Size, 90 Degree Elbow
8- 4568K139    Standard-Wall Brass Threaded Pipe Nipple, 1/4 Pipe Size X 5" Length
9 - 50785K222 Medium-Pressure Brass Threaded Pipe Fitting, 1/4 Female Female Male Tee

Substitute items whenever practical. For example I couldn't locate a regular brass elbow, but the nickel plated was available; nipples could be iron etc.

All of these connections are made with gas rated pipe dope. This helps seal the threads and makes it easier to disassemble later.

Note: You can take the handles off the ball valves and reorient them to a more useful position. Simply undo the nut rotate the handle (not the valve) and put the nut back on and tighten.

Position the torches into the burner tubes. The tubing adapters and MIG tips have to be removed to fit into the torch bracket. Leave the setscrew on the torch bracket loose. This will allow us to slide the torch in and out inside the reducer and tune the burner. Thread the nipple back onto the reducer adapter.

Once you have everything plumbed, close the ball valves, close the regulator and make the connection to the tank. Fill a squirt bottle of water and few drops of dish washing soap added. Keep this handy. Open the tank valve and squirt the regulator inlet. If no bubbles appear, open the regulator and check each connection from the regulator, to the gauge and all the way down to the ball valves. If you have some bubbles at any connection, Turn the tank valve off and tighten the connection (sometimes a 1/4 turn is all it needs) and recheck it again with soapy water.

Tuning


Place or fix the burner assembly to something that won't catch on fire.

Loosen the flare setscrews. Start with them flares about 1" past the end of the 3/4" pipe.

With the regulator open, open one of the ball valves and hold a flame (BBQ lighter/propane torch) in front of the flare end. If it lights and stays roaring you are doing well. If it sputters and goes out, you'll need to adjust the position of the torch inside the bracket and/or adjust the amount of the flare is sticking out. We're looking for a strong blue flame with not too much yellow or orange tips.



Once one burner is tuned. You can shut it off  by closing the ball valve and lock all the setscrews down. Set the torch and the flare positions on burner #2 to what you have setup for burner #1.






Next we'll build the body of the forge.

13 comments:

  1. What are the burner tubes constructed from? Thanks!

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    Replies
    1. The burner tubes are 3/4" schedule 40 pipe. Threaded at one one. Cut an 18" nipple in half. ;-)

      Dan

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  2. How does the mig tip connect to #5? Thanks and awesome stuff here.

    ReplyDelete
    Replies
    1. Hi Trevor,

      The MIG tip fits into the tubing adapter by compression. The adapter is meant to squeeze down on a 1/4" pipe.

      Dan

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    2. How do you connect the burner to the assembly and what does the burner consist of

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    3. Hi,

      The burner connects to the forge body through a collar with three bolts that hold the burner tube. Gas Forge Build 1: Concepts and Burner Tube for the burner tube construction.

      The collar on the forge body is described here: Gas Forge Build 3: Forge Body

      Hope this helps. Good luck!


      Dan

      Delete
  3. Where did you find the 1" to 1/8" reducer that slides over the 1/8" nipple and how did you clamp it down? Do you drill the holes your self and where did you find the screws to screw down on the nipple

    ReplyDelete
    Replies
    1. Hi,

      1" to 1/8" reducer. I don't understand. Is this the 1/4" to 1/8" reducer by chance?

      On the flare, I drilled and tapped some stainless steel tubing. It fits over the 3/4" pipe and the setscrews at 120° make it secure.

      Delete
  4. Thank you for all your help but I'm referring to the piece between the Bell reducer and the 1/8 nipple the part that threads inside the one inch Bell reducer and that goes over the 1/8 nipple where did you find that piece where did you make it yourself if so what are the dimensions

    ReplyDelete
    Replies
    1. Hi Seppo,

      I think I understand now. That is a piece of 1.5" x 3" nipple I cut in half and welded a piece for holding the collar which is schedule 40 3/8" pipe. This can be seen on this page: http://dcknives.blogspot.com/p/gas-forge.html

      Dan

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  5. Sorry I just have one last question how did you weld the piece together? What process did you use?

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  6. I used a wire feed welder with flux core wire.

    Dan

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  7. Is there any way to connect an acetylene regulator with a 9/16-18 output to a propane hose? I have an oxy acetylene torch that I also use with propane, and I am struggling to find a way to build a gas delivery system to connect to a 1/2" iron nipple as the burner tube.

    ReplyDelete