Propane Forge

[Geoff Keyes 494]

Some of the modern valves have flow restrictors built in , so that if gas begins to flow too fast, it shuts down.  I don't know how to bypass without simply moving to an old tank.

 

Geoff 

[Brian Dougherty 1,091]

Nevermind, Geoff beat me to it...

Edited April 30, 2020 by Brian Dougherty

[timgunn 31]

As mentioned, some systems have a built-in flow-limiting valve. It is broadly similar to the "air fuse" sometimes fitted to pneumatic systems before a hose. The idea being that if the hose gets cut, the air fuse will close and limit the airflow, so you are not having to deal with several yards of angry hose thrashing about and trying to beat you to death. It will limit the flow to some (fairly small) fraction of the maximum design flow and will automatically reset when the flow drops to zero (or near-zero). With a gas system, the potential is for several yards of angry hose with several feet of even angrier flame issuing from the end, so it's a pretty good safety feature really. 

 

If you have such a system in your cylinder, it will be designed to limit the flow once it gets over the maximum design flow for the cylinder. The supplier should be able to tell you what the maximum design flow is. You can then calculate what your burner takes at different pressures using the BTU calculator on Ron Reils site (other calculators are available) and see whether or not it'll do what you need. It is always a good idea to back off the regulator before closing the cylinder valve and to open the cylinder valve before increasing the pressure with the regulator. Opening the cylinder valve with the regulator turned up can cause an initial flow surge that may be enough to trigger such a safety system.

 

 

[Mike Ward 90]

Thanks guys. I think that’s the issue, however I’m only running at 6 psi and it was in the middle of the forging session where it was running for awhile. In the future though, I’ll turn the regulator down before turning on the gas just in case.