Jump to content
I Forge Iron

Propane supply hose diameter


Recommended Posts

Apologies if this has been addressed already... I'm a bit dizzy from reading the Forges & Burners 101 threads for the last couple months and can't seem to find or recall seeing this discussed.

I'm setting up for my first propane forge and am putting together a shopping list for hoses and connections from my local propane supplier.  Looking to power one to two 3/4" burners with 6 to 10' of hose.  In looking at the hoses in their catalogue, they have 1/4, 3/8, and 1/2" Type 1 rubber propane hoses available.  Can someone please let me know if 1/4" is fine for this purpose, or if a couple 3/4" burners may be hungry for more flow than that could provide?  The catalogue states 350 psi rating for all the hose diameters but doesn't list cfm...

I am hoping to follow Frosty's advice to keep my intentions mysterious when speaking with vendors :)

Also, as I am dreaming of eventually building a larger forge (the 2 burner scenario) which I could use with the same regulator & hose, are propane-rated quick connects generally considered safe for gas forges?  My thought was to have the hose terminate in a quick connect, which would be connected to a ball valve at the burner.  That way I could separately stow away the forges, hose & regulator, and propane tanks when done for the day as I have very limited space.


Link to comment
Share on other sites

3/8" propane rated hose works a treat for me eve with an OLD 0-20 regulator. It's never starved my burners and one forge runs four 3/4" T burners though I rarely fire up more than 2.

3/8" hose pretty much the standard for most things so you don't need to figure out what fittings to buy to match up.  Go with a new 0-30 high pressure adjustable regulator with a hand screw tank connection. It's too easy to over tighten the regulator to the tank and it messes up the seats. SNUG is good but don't be bashful about swabbing a little soapy water to check. RIGHT? You don't want to assume the extremely flammable gas isn't leaking. You know that whole "making assumptions makes an ### of you and me" thing? 

I do NOT recommend quick disconnects, even propane rated ones. They cost a LOT and tend to start leaking much sooner than I like. If you're planning on building a two burner forge you'll want a manifold at the forge. Unscrew the hose from the forge and wrap it around the top of the regulator on the tank. You don't REALLY want to store rubber hose with a box that's 2,600f. on the inside do you? The fittings on a propane hose are designed to be removed and installed repeatedly for decades. Don't forget to soap them once in a while. ;)

Frosty The Lucky. 

Link to comment
Share on other sites

Thanks Frosty! 

That is great info - I've learned so much from this site and would really like to thank you and the other curmudgeons for sharing your knowledge and being so generous with your time. 

I was thinking of storing the tank, hose & reg, and Forge & burner each separately but good general reminder about never wrapping a hose around hot things...  

I'll skip the quick disconnects as suggested.  Besides convenience, I was partially concerned with wearing standard fittings out if I unscrew them after each use - that's good to know that it isn't much of a concern.  Though as suggested I'll leak test them frequently.

I know you recommend copper pipe for the forge connection, but I'm planning on rubber hose for now (to keep the system more portable) while trying to keep the end of the hose away from heat as much as possible by burner, elbow, & ball valve orientation.  If I'm disconnecting a regular fitting (1/4 NPT or 9/16 or some other standard threaded attachment) at the ball valve attached to the burner after each use, should I be applying pipe dope to the threads each time I hook it back up?


Link to comment
Share on other sites

If you're running a single burner the rubber hose will be fine, especially if the burner isn't on top of the forge. Otherwise just be careful to keep the hose out of the hot areas where exhaust is rising.  

I like the ball valve between the regulator and hose but there is good reasons for putting it on or near the burner.

Right after the regulator lets a person shut the propane off quickly if something goes wrong at the forge say a broken gas line resulting in billowing flames. It can take a little time to shut the tank valve, not a lot but being in the presence of an our of control fire seconds seem like a long time. A 1/4 turn ball valve can be closed with a flick of a wrist or thrown glove. I've never seen a broken propane line on fire, I'm just a conservative kind of guy.

The benefit of putting the 1/4 turn ball valve on or close to the burner puts you close when you light the forge. Lots of guys like to use a butane torch so having the valve close works well. I use a little ball of burning paper so I can stand by the propane tank.

The fitting swaged to the hoses are intended to be installed and removed frequently and don't seem to leak if snugged well. I've never doped one and don't know of anyone who does. However it'd be a good idea to ask someone at a Propane supplier, I call Petrolane if I have questions.

Frosty The Lucky. 

Link to comment
Share on other sites

Larger burners (or torches) require larger diameter hoses, BUT the figures recommended for fuel hoses  suppose twenty foot sections. You are not likely to get into trouble with a 1/4" hose of four to six foot length. Once again, circumstances alter cases. Also, a 3/8" size torch hose is far more flexible than 3/8" gas  appliance hose...

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.

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...