I recently decided to make a small burner for a small forge. This burner is easily made with a minamum of tools. It is suitable for a small chamber size of 80 to 100 cubic inches.
And should run at a pressure of 15 psi or higher. At 15 psi the output is 12000 btus. In a small chamber it will take a 3/8 square bar up to a reasonable yellow temperature.

The 3 inch nipple has a thin piece of steel welded on the end to cap it. The overhang is then ground smooth to match the line of the pipe, and the end is ground perpendicular. I drill 1/64 hole in the centre of the end as the gas oriface. The 1/8 pipe fits with only a little slop and is secured in place with a 1/4 inch set screw. I have drilled 12, 1/4 inch holes just past the set screw. The other end is threaded and a standard 3/8 coupling is threaded on. Attached to the other end of the pipe nipple is 1/8 street elbow and a valve. I would recommend a ball valve, but in this photo I have used a needle valve.

The next image shows the burner running at 15 psi.

I have also had success with a modification of this burner for glass bead making. This is not a hot torch so the glass melts slowly but it supplies enough oxygen to keep the glass from getting smoky. If you have questions about this modification please email me.