Old 09-14-18, 03:32 PM
  #22  
Doug Fattic 
framebuilder
 
Join Date: Dec 2009
Location: Niles, Michigan
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My preference for an oxygen concentrator manufacturer is DeVilbiss. I have an older model 515 with 18,000 operating hours. It is still working fine. The newer 525 is supposed to be quieter and is dark gray instead of beige. It can have a higher oxygen output than a couple of Invacare models I also own (so I can have several torches in my classes operating at once if necessary) even though they all are rated at 5 liters per minute.

Another reason I like the DeVilbiss better is because its output fitting is a standard B that a welding hose can directly screw into. The Invacare has a barb fitting designed to hold those clear plastic hoses that carry oxygen to a patient. Often they come with a plastic adaptor that has a barb on one end and a B fitting on the other. So it works to attach a separate plastic hose to the unit and the plastic adaptor which allows a welding hose to screw into the adaptor. But this extra stuff seems unnecessarily complicated even though it works okay.

And the 3rd reason I like my DeVilbiss better is because the warning signal on my Invacare – when I accidentally shut off the oxygen flow after doing a braze – is more piecing loud. And it won’t shut off when I open the oxygen knob again on my torch handle. I have to turn the machine off and on again. The Develbiss stops yelling at me when I open the flow knob again. None of those preferences would matter much to me if I got a really good price on another brand.

I bought my 1st oxygen concentrator from M&M Medical Repair in Beaverdale, PA (a very small town in the middle of nowhere). I discovered they were the source for various used Oxygen concentrator suppliers. I paid $300 + $30 shipping. It came with a 3 year guarantee. After a couple of years my concentrator wasn’t putting out enough pure oxygen and they repaired it for free (I paid for a new filter). The reason this might be a sensible option for some just getting their brazing equipment is that one can choose a Devilbiss 525 and have the assurance of the guarantee. In bigger cities oxygen concentrators can be randomly found for $150 to $200 (and some of my students have paid less) but sometimes they have some issues that have to be sorted out and repaired. They are pretty complicated inside. Those that are mechanical can figure out how to get them fixed while others just want something that works. $300 is not much different than what the cost of a oxygen tank and regulator would be and of course there is no cost of refills. For some this is really the only option because of pressurized tank restrictions where they are located. Where I live I haven't seen one on Craigslist within 50 miles of me for as cheap as $200 for a long time. So how long someone is willing to wait for the right machine is part of decision on where to buy.
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