Can I hook up a concentrator and a tank at the same time?
 

I keep thinking I might want to be able to have the extra oomph from it. I may not need it at the moment with soft glass, but I'm sure I would when I start working boro. I know it's doable, I just can't hit the right keywords to find it when searching.

Oh, I've got a minor.

It's a millenium concentrator, if it matters. My daughter had to have one for her bi-pap after her second hospitalization for pneumonia in 3 months, and woo-hoo, she's not going to need it any more soon!

Amazingly enough, the doctor knows I want to use it and is perfectly fine with it, LOL. I asked if he wanted us to keep it (honest to goodness, my motive was so that if she got sick again and needed it we wouldn't have to wait 2-3 days to get one before she could come) and he said that he'd have wanted us to keep it and was about to say so. My 14 year old had to pipe up and announce that I wanted to keep it for glassworking, and the doctor thought it was very cool and actually pondered getting her an oxygen generator for a moment, LOL. I clarified my motives to him, and he said it would be fine for me to use it, just that he would deny all culpability if asked.

So, enough babbling.

Also, if I'm just using a concentrator, do I need a regulator?

Thanks much!

no. the concentrator has an internal regulator.

It's not possible on a two-port torch. On four-port torches, it's easy enough to do. Hook the concentrator to your center fire ports, and the tank to your outer fire ports.

Some of the large generators have tanked oxygen backups, but, honestly if you are in the market for a $10,000 generator, you probably are going to be running a torch larger than a Minor.

There is someone on this board that does it...although I forget who...

I believe she uses a y connector the same as if your ganging 2 oxycons and set the pressure on her ox tank to match the output of her concentrator...

I just did a search and cannot find the post...maybe I imagined it hmmm...

In theory it should work although I would wonder if the tank has so much more umph it may not let the oxycon flow also.

Doesn't seem like that would work. The oxygen concentrator's output changes when you increase or decrease the oxygen on the torch. The pressure from the tank doesn't.

Sounds to me like it would create more problems than it's worth...

I think the way it works is you don't adjust the flame with your oxygen knob you adjust your flame by adjusting the gas knob. This was someone that had a National 8m and to run that w/one oxycon you keep the oxy open all the way and adjust the flame with the gas...thats the set up I have but I haven't ganged up the oxygen tank. I've been thinking about it because my flame is weak but good enough for soft glass.

Kbinskter might know something about this...

The only way it will work is with a backflow preventer (not a flashback arrestor). BFP's allow the gas to flow in one direction only. It should be put on the oxygen line from the concentrator immediately before the wye. And as Cosmo says the regulator on the oxygen tank should be set at the same pressure as the concentrator is.

I'm still not sure why you want to do this though. Tanked oxygen is at a higher purity than concentrator oxygen is (by about 2-3 percent), and all you are doing is diluting the tanked oxygen.

I'd say use one or the other, but not both at the same time unless you have a 4 port manifold and can run an independant center fire.

You wouldn't have very much control of your flame that way.

Sounds like a bad idea to me...

I've worked w/a tank and the way I described above and I have fine control over my flame. Not ideal but good for not having to fill my tank every 4 days or so.

There are some threads about working the National on an oxycon like this around here somewhere. I think Marylin from Zingz posted this information from talking to the National people. Also this is what the company I bought my oxycon told me how to work with an oxycon, adjust at the oxycon your flow not at the torch, it puts stress on the oxycon if it has backflow...that's what I was told so I'll go my the suppliers info. If I want an oxidizing flame I have to turn my flame way down though but I can get it to oxidize...I wouldn't recommend this for a newbie trying to figure out what type of flame they are working with though...I've been working w/glass off and on for almost 10 years now. The National 8m uses/needs more oxygen psi than other torches.

You could "Y" the concentrator and the tank together and only run one or the other for whatever application you choose, though, but not have to switch out connections. For soft glass beads, a 5 LPM concentrator is usually sufficient. If you have a concentrator that puts out poor quality, you may have trouble with getting enough heat for that, though.

Although concentrators do put out slightly lower purity than tanked oxygen, there should not be a big difference between a new unit or a properly reconditioned medical unit and tanked oxygen. I have run my Regalia and the DeVilbiss units I sold on a few different torches and compared them to tanked oxygen. The "strength" of the flame was about the same.

I have used other concentrators that had a higher output pressure than the manufacturer originally designed into the machine (more thrust for the flame), but the flame was "weak." You could tell that it was much cooler just by looking at the intensity of the blue in the flame. The flame tends to be more reducing because the concentration of oxygen is so low. If you were to add tanked oxygen to this, you would probably increase the overall concentration of oxygen, but it would still be poor compared to tanked oxygen alone or the oxygen from a new or properly reconditioned concentrator (one that has been reconditioned and not altered to perform beyond the manufacturer's specifications).

If you want to try connecting a tank to your concentrator, then make sure that you have a backflow prevention valve on your concentator line, so oxygen from the tank could not push itself back up the line into your concentrator. Set your oxygen regulator (with your torch running) to the psi your concentrator puts out (maybe 1 or 2 psi lower). As mentioned above, you do not need an external oxygen regulator for your concentrator. You should have more volume available to your torch, but not more pressure (unless your concentrator does not really put out the psi claimed and your tank is really doing all the work). Look at the flow meter on your machine and watch what it does.

Just side note...
Johnny O. told me that he has connected two tanks together so there is no interruption in oxygen deliery when one tank empties out. You just set one tank to a higher psi than the other. When the higher psi tank empties, the lower psi tank is then able to get its oxygen into the line and there you go. That Johnny O. is smart.

And just to reiterate what Kimberly and I said: be sure a backflow prevention device is in the concentrator line!!!!!!!! Even at the same delivery pressure, back flow into the concentrator is A Very Bad Thing.

I thought all oxyons already had a backflow prevention valve... at least all the Invacares and AirSeps... and the Sequals -- located internally just prior to the inlet side of the flow gage.

Does the Devilbiss not have one?

Me

I'm talking about an commercial/industrial type of BPD, not the medical kind. The medical kind are designed to prevent liquids from getting into the concentrator (for example: saline used in breathing therapy). They usually don't prevent full backpressure (and flow) of 7-10 PSI of pressure back into the concentrator.

Concentrators have built-in alarms for stoppage of the air-line, but full blown back pressure can blow out valves etc. A Very Bad Thing.

According to Justin (Oxygen Plus) there is a internal check valve (BFP) on concentrators under the cover .........

Dale

<snort>

I ran a redmax on a combination of generator and oxygen for about a year. It was a complex rig that I wouldn't advise anyone to use, but here is the idea. The volume that a generator will put out won't drive both torches and the pressure falls to nearly zero when you open up the upper and lower torches. I put a Y in at the torch. The kind of Y that has a knob valve control. I'd set the tank pressure up at 8 or 9 PSI (which my generator put out).....when I'd want to use the lower torch I'd also cut the tank knob on at the Y. Complex...but it allowed me to save the tank for use only when I used the larger torch (seldom) and kept me from having to buy tanked just to run the top. Hope this made some sense.

thanks so much for all the input!

I kept forgetting to look at this thread...I just know I've seen this done, and can't remember where.

I'll do some research on the brand of concentrator and see if I can find out if they have a back flow prevention device sufficient for this idea. If I can't find out with complete certainty, I'll get one.

Thanks Dale. I was unsure of the Devilbiss. We have experimented with various poppet and ball type exterior mounted check valves, searching for the proper combination that would ensure any oxycon could succesfully gang with any other oxycon. We used valves with crack pressures from 2"WC to 5 psig, and rated for operating pressures to 100 psig. The vision was a wall of used oxycons... say 10 units... putting out 50-75 LPM (~100-150 CFH) at ~7.5 psig. All working in unison, and with only as many as needed operating (1 to 10 units). In the end we found two things.

1. The oxycon's internally mounted check valve, commonly referred to as a back flow prevention valve, would prevent return flow at pressures up to 125 psig. The valve is generally a push fit hose-to-barb connection, and on some machines it did not have a clamp at that connection. At approximately 25 psig back pressure (valve locked) the hose-barb connection disengaged. This actually is good... before the back pressure could reach 125 psig the system 'safed itself', venting the back flow... although this probably was not a intentional oxycon design feature :). However, it does require opening the unit to reconnect the hose and valve.

2. After various equipment (Invacare - AirSep) and valve configuration tests, it turned out that the way to enable any number of oxycons to chain-gang to any other oxycon was a simple, external modification to the oxygen hose, and required no parts -- thus with nothing to 'sell' there was no potential profit reason to pursue it. As a plus, it also prevented the condition which leads to auto-shutdown (and alarm) from occuring if the torch oxygen valve is closed and remains closed while the oxycon is operating. The oxycon (or gang of several) is operated like a 'virtual oxygen tank'. The 'tank valve' is the oxycon on/off switch; the 'pressure regulator' is the flow valve. No need to remember to open and reopen the torch oxygen valve to prevent an alarm.

Me

(p.s... yes :wink: we know that pressure regulators, and flow regulators are not the same -- it's just an analogy).

Okay, I have read through this thread...still confused over here, lol. I am adding a 3rd concentrator to my set up. I have an Airsep 5 liter unit, a Caire 6 liter unit and an M-15. Do I need back flow vavles in the tubing? I already have them on the two smaller units but do I need to add a 3rd?

If all you are doing is adding concentrators to an existing setup that does not have an oxygen TANK involved, then no, you don't need an extra backflow valve.

Alrighty then. Thanks:)

The only way you can have a tank and a concentrator hooked up to the same torch is to have the tanked hooked to your bigger outer flame and the concentrator hooked to your smaller inner flame. with our without foot pedal on the ouiter to conserver tanked o2 when not needed.

If you have a tank and a concentrator hooked up to the same line no matter what you do there is no fitting or plumbing thats going to easily change the fluid dynamics of the o2. If the pressure in the line from the concontraters is at al lower then the pessure the tanks reg is set at it. the tanks pressure will always over come the pressure of the conentrator, If the tank pressure is lower then the concentrator then the concontrater will be the dominitt force and inless the pressure ever drops below the tanks pressure the tank will not feed the line. Gas wants to always take the path of least resistance.
A back flow preventer will only keep the tank from filling up the holding tank in the concentrater to the pressure the tank is set at and visa versa.

If this is true then how does ganging up 2 or more concentrators work? Is it because the LPM is similar and tanked O2 has prolly a much higher LPM delivery?

TIA

It is because the psi is similar.

That still doesn't make sense then in relation to tanked oxy if you set your regulator to the same pressure as your oxycon then the results should be the same...

Thanks for answering BTW :smile:

You you can do it if tank regulator pressure is set same as concentrator out put pressure... Yes it will give you more volume (LPM) to torch... Keep in mind that tanks are not "infinite" source as compared to concentrator (s)... It just does not seem practical when whole idea of concentrator is to eliminate tanks.... but if you need short term boost in volume it will work, but then with available tank volume, you don't need concentrator on line....

Dale

Well, keep in mind that your hose will only hold so much (volume). If you were somehow able to exactly match the pressures of the concentrator and the tank, then what would happen? Maybe the LPM setting would drop to adjust for how much volume the tank contributed. I guess it depends on the size of the concentrator. It would be interesting to test it out and see.

But, when people talk about a boost, it is usually a function of pressure (to get additional thrust). With the tank and concentrator set-up, if it would work, you would still be limited by the pressure of the concentrator.

Boost

Noun

1. The act of giving hope or support to someone.

2. An increase in cost; "they asked for a 10% rise in rates".

3. The act of giving an upward push; "he gave her a boost over the fence".

Verb.

1. Increase; "The landlord hiked up the rents".

2. Give a boost to; be beneficial to; "The tax cut will boost the economy".

3. Contribute to the progress or growth of; "I am promoting the use of computers in the classroom".

4. Increase or raise; "boost the voltage in an electrical circuit".

5. Push or shove upward, as if from below or behind; "The singer had to be boosted onto the stage by a special contraption".

http://www.websters-online-dictionar...finition/boost

Dale

Thank you, Dale, for posting the definition of "boost." However, I must tell you that when I mentioned "boost" in my post, it was not in response to the "boost" in your post - as I was still typing while you posted and had not read your post until after I posted. So, just so you know, I was not disputing your definition of "boost."

ok... I with draw the smart a$$ part of my remark...

Dale