oxygen concentrator for jewelry making

Using an Oxygen Concentrator With Torches Instead of Tanks

So, you’re ready to upgrade from a butane torch to an oxygen and propane torch, such as the Smith Little Torch. It’s a very popular option, and once you’ve tried it, you’ll never go back!

What should I use for oxygen in my Smith Little Torch Soldering/Welding setup?

There are a couple of possible issues that you’ll probably want to avoid. Lots of folks don’t want to keep large propane or oxygen tanks in their homes, including us, for the obvious safety reasons. So, we’ve opted to use the small, 1-pound propane tanks that are commonly used for camping. I know some folks use a barbecue propane tank, but that’s way too much propane to have in the house, in my opinion. So, we’ll stick with the small tank. Those small propane tanks actually last quite a long time, and they’re inexpensive, so it’s not really an inconvenience.

You’ll go through oxygen a lot faster, though. Some people go with the large oxygen tanks you get from a welding supply house, but that’s too much oxygen for us to have in the house – again, for safety reasons. And, there are the issues of transporting those big tanks safely. Unfortunately, the small disposable oxygen tanks don’t last long (from what we hear), so you’ll probably want another solution.

For lots of jewelry makers, the ideal solution is to use an oxygen concentrator. They’re expensive new, but you can readily find used ones that have been decommissioned from a medical oxygen supply company. (Used oxygen concentrators need to be thoroughly cleaned and sterilized before they can be used again, so they often go straight to a landfill instead.) Sometimes, an industrious person will clean them up sufficiently and resell them somewhere like Facebook Marketplace (which is where we got ours) or Craigslist. Rio Grande sells them, too, but since they’re heavy, and somewhat costly to ship, you’re probably better off buying one locally.

Buying tip: Don’t be afraid to negotiate on the asking price. Sellers who have access to decommissioned units typically have a small inventory of them, and have minimal costs, so will strike a deal readily. (I messaged my seller, pointing out that I could get one elsewhere for $150 less than he was asking, and he instantly accepted my offer. I did check him out on Facebook first, to make sure he looked legit.)

Now that you’ve acquired your oxygen concentrator, how do you set it up? It’s really very easy. You’ll need a few parts, but they’re easy to obtain, and inexpensive.

A quick overview of the oxygen concentrator + propane tank setup

Leslie Kail Villareal has put together an extremely helpful video on gathering the parts and putting them together: https://www.youtube.com/watch?v=ygT64TYMhfY&t=597s
(Note: the video has some interesting info on using the Smith Little Torch with a full-size oxygen tank, but this link places you where she starts talking about the oxygen concentrator setup.)

Leslie even lists out the parts you’ll need for your oxygen concentrator setup. She recommends buying the fittings at a local Airgas store, but we don’t have one anywhere near us,  so we bought ours via their online store.

One issue to consider is that the oxygen concentrator can beep a lot. It beeps when you start it up (notifying you that its current oxygen output is not sufficient for a patient) – obviously, not a problem. However, when you turn off the oxygen valve on your torch, the oxygen concentrator senses too much pressure, so emits a continuous beep, which is super-annoying.  I’ve heard it can also damage the machine over time – trying to push out oxygen when it’s blocked. The solution to this is to add a pressure relief valve to your oxygen line, between the concentrator and the torch. It’s simple to do, given a couple more fittings. Basically, we add a T-connector in the line between the concentrator and torch, and attach the pressure relief valve to the new (short) tubing line.

Your oxygen concentrator + propane cylinder setup parts list

So, here’s the list of parts you’ll need for your oxygen concentrator setup, complete with pressure relief valve:

The tubing:

EZ-FLO 1/4-in ID x 10-ft PVC Clear Vinyl Tubing (3 feet will be plenty) – available lots of places

https://www.lowes.com/pd/EZ-FLO-1-4-in-Inner-Diameter-x-10-ft-PVC-Clear-Vinyl-Tubing/1000365025?idProductFound=false&idExtracted=true

The brass fittings that go in the tubing to connect the oxygen concentrator to the torch: (these next 3 parts connect together, in the middle of the tubing)

RADNOR™ 9/16″ – 18 B – 1/4″ ID Brass Oxygen Hose Nipple Set

https://www.airgas.com/p/RAD64003987

RADNOR™ 9/16″ – 18 B RH Brass Oxygen Hose Nut Set

https://www.airgas.com/product/Gas-Equipment/Support-and-Maintenance/Gas-Fittings-and-Adapters/p/RAD64003986

RADNOR™ 9/16″ – 18 B RH Brass Oxygen Hose Coupler Set

https://www.airgas.com/product/Gas-Equipment/Support-and-Maintenance/Gas-Fittings-and-Adapters/p/RAD64003995

The T-connector that goes in the tubing, to allow us to attach the pressure relief valve: (it goes in the tubing, between the oxygen concentrator and the 3-part connection to the torch hose)

Proline Series 1/4-in x 1/4-in Barbed Tee Fitting:

https://www.lowes.com/pd/B-K-1-4-in-Barbed-Tee-Fitting/1000505091?idProductFound=false&idExtracted=true

The pressure relief valve:

Pressure-Relief Vent, Zinc-Plated Steel, 1/4″ NPTF, 1-1/8″ Overall Height, 1 to 5 PSI

https://www.mcmaster.com/catalog/130/2559/1093K21

The barb fitting to attach the pressure relief valve to the tubing:

https://amzn.to/49tlahL

The brass coupling to attach the pressure relief valve to the barb that goes into the tubing (note: on the Amazon product page, you may need to click on the “See All Buying Options” to buy a single coupling, unless you want to be forced to buy 5 or more adapters, which was the case last time we looked) :

Parker Hannifin 207P-4 Brass Coupling Pipe Fitting, 1/4″ Female Thread x 1/4″ Female Thread

https://amzn.to/3SWuYL3

 

And, now for the 1-lb propane tank setup parts:

All Purpose Propane 16oz, 2-Pack Pre-Filled Green Steel Propane Tanks – Lightweight & Portable – buy them lots of places

https://www.lowes.com/pd/BernzOmatic-1-lb-2-Pack-Pre-Filled-Propane-Tank/50235565?idProductFound=false&idExtracted=true

Regulator for the propane tank:

Smith Non-Gauge Regulator for Disposable Propane-MAPP Tank (note: they refer to it as “disposable” – that means it goes on a disposable tank – the regulator itself is not disposable.)

https://www.riogrande.com/product/smith-non-gauge-regulator-for-disposable-propane-mapp-tank/500093GP/?code=500093

The flashback arrestor that goes on the 1-lb propane tank:

Harris 88-5BR Flashback Arrestor (set) – Regulator Mount 4301651

https://store.cyberweld.com/products/harris-88-5br-flashback-arrestor-set-regulator-mount-4301651?variant=43707920318691

A stand, to hold the propane tank upright:

Stansport Propane Cylinder Base

https://amzn.to/3OH8M53

And the Velcro ties we used to attach our propane tank to our table leg, for stability (just one solution of many):

YiwerDer Reusable Fastening Cable Straps and Cable Ties Set 20 Pack(8″-12″-18″)

https://amzn.to/42FZ4pr

 

A few usage and other tips:

  • Here’s a video on preventing pressure buildup in the concentrator, which we followed to figure out how to eliminate the oxygen pressure buildup (and beeping) problem: https://www.youtube.com/watch?v=t27UXsseF44
    • It includes a tip to keep a clean air filter in the unit
  • Here’s another video showing use of the pressure relief valve on the oxygen line: https://www.youtube.com/watch?v=xJOfaE0LLw0
  • To protect concentrator filters from becoming contaminated by fuel gas backing up in a torch (that can happen), then flowing down the oxygen line to the concentrator, a check valve should be installed on the concentrator output. This is a one-way valve allowing oxygen out of a concentrator but blocking any gas from going back into the concentrator and contaminating its filters. Our oxygen concentrator has a check valve built in. You may want to verify that yours does too.
  • You do not need a flashback arrestor on the oxygen line, since oxygen is not explosive like propane is, and adding that device will reduce the already low pressure output of the oxygen concentrator.
  • You should start your oxygen concentrator 5 or 10 minutes before you start using it, so it can start generating oxygen. (It takes a few minutes to get the concentration up to the right level.)
  • You should run your oxygen concentrator for a 20-30 minutes every month, even if you’re not using it, to keep it in good working order. (Apparently, if you don’t, it’ll malfunction or fail.) I’ve seen recommendations to run them for 4 hours per month as well – there doesn’t seem to be agreement on the duration – just that you wan to run it for some time every month to keep it in good running condition.

 

 

 

1 thought on “Using an Oxygen Concentrator With Torches Instead of Tanks”

  1. Thank you for this! I’ve been trying to figure this out for at least two years! You are so kind to have put this together for your wife and so generous to share with others.

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