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donaldduck
2007-10-30, 12:10pm
For the love of GOD, people, I could really use a straight answer...

My mother and I have been using hot head torches for the last six months or so, and are frustrated by the freezing up and the constant bottle changes. We took the leap and ordered 2 GTT Bobcats, and two 5LPM oxycons from pyronamix, which have been sitting at the house for months now, waiting for us to pull the rest of the studio together. Mom remembered that we have an unused residential propane line running to our laundry room, which butts right up against the rec room, where we were planning to install torch space. We've got the floor, the bench, metal backsplashes, a 500 cfm vent fan and plans for a DIY hood solution, and last week, I called the gas company to talk about the gasline.

I've seen a lot of discussion here about natural gas and Bobcats, but little or nothing about using residential propane. (One might start thinking, gee, perhaps there is a reason for that?) I scheduled a consultation with a rep for our local gas company and met with him last tuesday to explain what our goals were, and show him the gas connection, the torch, the hoses, and everything else we'd amassed. Roger (We'll call him by his name, because it's quicker to type than "clueless unhelpful money-grubbing moron") assured me that everything would work perfectly fine, they'd run the gas line through the wall to the opposite side, adjust it to our desired height and fit everything out for $400. Which...to be honest, seemed really high to me, (the "adjustment" is about 6-8") but I wanted it done quickly, and he was able to schedule the appointment within the week, which brings me to this morning.

At 9 a.m., Jimbo-the-installer (a very nice, knowledgeable, respectful and HELPFUL individual, but again, "Jimbo" is shorter to type) arrived to begin the work. I walked him again through our goals, and he pointed out right away that Roger had given him the wrong nozzles to install, and that we'd need adaptors to go from the house line to the hoses. He also raised the question of what pressure our propane lines were, though apparently (according to the propane guy at our supplier. We'll call him "Chad", because that's his name, but he gets even nicer descriptors than Jimbo, despite being the bearer of bad news. He is awesome.) it ought to have been a no-brainer that the line in question, being meant to supply a gas dryer, could only be a 1/2 psi line at most.

I talked to someone at GTT (unfortunately, I didn't get his name. My bad. But also extremely helpful) who said that the torch could run at 2 psi or even 1 psi, no problem, which (since I hadn't yet spoken to Chad) reassured me that I was still okay. I've also seen several references in this forum and others to running small torches like bobcats and minors on 1/2 psi Natural Gas. Having since had the Chad-talk, (and to make an extremely long story much, much shorter....)

Can I run a GTT Bobcat on 1/2 psi residential propane, or not?

If the answer is no, then Roger is most certainly NOT receiving any of his $400. (And I'd like to charge him for the day and a half I've taken off work to meet with him, but I'm sure they won't pay it.) If the answer is yes, then he'll be receiving that amount, minus whatever else it costs me to adapt the 1/2 black malleable pipeline to my already purchased torch hoses, which he assured me they'd be able to connect by the end of the project.

Help me, Lampworketc gurus. You're my only hope.

Just Nancy
2007-10-30, 12:15pm
I wish I could give you a better answer. I had the same issue. I was told by my propane guys that they measure in water columns and I was going in psi (or something, I've forgotten now).

I went with a full pressure line off of our bulk tank and have regulators between my pipe and my torch. (And a flashback arrestor.) I'm also not in a house.

I know you can get the things to step down from the supply line, everyone deals with that. The pressure issue, I don't know. If GTT said you are good, you should be. They should know their torches. ~Just don't tell my husband because it was a pain getting the high pressure line in, but now I'm good for a much bigger torch.

Good luck.

donaldduck
2007-10-30, 12:40pm
Honestly, given the length of the house in question (our bulk tank is on the far side of the house from the studio), if I cannot run the torch with 1/2 psi propane, we're more likely to put a BBQ tank on the right end of the house and pipe it in that way.

(edited to add, FWIW, 1/2 psi is apparently 14 inches on the water column scale.)

Just Nancy
2007-10-30, 12:45pm
I'm not an authority at all but that sounds like it would be easier. (Not knowing for sure.) Lots of people are set up with a pipe through the wall. Then depending on the size of pipe you just get fittings down to the end of your hoses or actually your regulators. It wasn't that hard to find in the gas grill section of the local do it center.

Good luck.

I see others are reading, hopefully they're posting.

kbinkster
2007-10-30, 4:25pm
Can I run a GTT Bobcat on 1/2 psi residential propane, or not?

Yes.

The Bobcat can run on as low as 1/4 psi. Naturally, the more gas you have available, the bigger/hotter the flame you will get, so 1/2 psi would be even better. At about 3/4 psi, you will be able to get the top end out of the torch (with adequate oxygen).

If you're concerned about having enough pressure, have your gas guy put a gauge on the line and check what psi you're getting. If you think you have too much pressure, don't worry. You can have high pressure behind the torch - no problem. If it's too high, you would just regulate it down (with a regulator).

BTW, the guy at GTT you talked to is Wally.

Dale M.
2007-10-30, 4:53pm
Any torch that will operate correctly on 1/2 PSI (14 Inches water) of NG will operate just fine on 1/2 PSI propane....

Actually torch on propane will be a slight bit hotter that running on NG.

The piece needed to convert from the black iron pipe to your welding type hose is referred to as a "B" fitting.... Costs about $1 to $3 depending on where you find them... Generally a local welding supply will have them... Some people have even said local "ACE" hardware stores may have them....

66357

IF you run a dedicated line in house just for torches, you can legally bring in propane in with pressure UP TO 10 PSI... Its in National Fire Prevention Association (NFPA) codes ... You can eve get fixed pressure regulators at 2 -5 and 10 psi... Or just get an adjustable one.

Only reason your "installer" says you can't exceed 1/2 psi is that is all he has ever worked with because that is pressure almost all appliances work on ...

Dale

donaldduck
2007-10-30, 8:06pm
Thank you all so very, very much. You just totally made my day.

donaldduck
2007-11-20, 12:32pm
Okay, bumping this, because three weeks later, I still have no working torches. Is there anywhere I can order the part? Because we've now been to two different local welding supply places, and I've emailed a few hardware stores online, and I've turned up nothing. I notice, Dale, that in your email, the pictured item is 1/4" on both sides. The pipe I'm connecting to is 1/2". Do you think that's the problem? Every single gas professional I've presented this issue to has thus far been stumped, and I'm getting extremely frustrated.

(Edited to add: McMaster-Carr is one of the online sources I've stumped, btw.)

Dale M.
2007-11-20, 6:13pm
McMaster part number ...79215A2

http://www.mcmaster.com

Different name same item.........

About 1/2 inch supply pipe to 1/4 threads of fitting.... Use " bell reducer" or a "bushing" (which ever is appropriate) on outlet side of gas shut off valve ( 1/2 inch) to match difference in sizes (1/4 inch)..... It can be brass, galvanized or black iron.. The "gas" does not care...

http://www.plumbingsupply.com/blackfittings.html

Almost everything is "standard" plumbing parts that is hardware store available (try local ACE) or professional welding supply parts and most hoses, regulators, and misc. "stuff" for lampwork torches is adapted from welding industry.


Dale

donaldduck
2007-11-21, 8:35am
Thank you so much, Dale. My only problem now seems to be finding a bushing that reduces from 1/2" to 1/4". Maybe the useless gas guy can manage that.

Dale M.
2007-11-21, 9:26am
Thank you so much, Dale. My only problem now seems to be finding a bushing that reduces from 1/2" to 1/4". Maybe the useless gas guy can manage that.

Go to local hardware store or building supply!... In plumbing section........

Dale