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

It might be me flamefilly is talking about, I posted about that in another thread. ;) I have my tank and Devilbiss hooked up to my National 8M when hubby uses it, since I run the Hurricane with my Barracuda and don't use tanked oxy or the 8m much anymore. We turn the concentrator on full flow, then make sure the psi is no higher on the tank than the concentrator is. They both connect to a 'y' into the torch, and it sure uses the tanked oxy a lot slower than just the tank alone. It's cheaper to run it that way, since a Devilbiss doesn't use as much electricity as my generator to run and it prolongs the time between getting our tanks filled. My hubby set it up and maintains my studio so I know it's safe, since he's a chemical engineer and very handy. Good luck!

The concentrators work because of being so close in pressure and flow.

If you got the psi matched exactly right. It would kind of work. lets say a hypothetical 9lb psi. is the pressure your looking for.
If you have both set at Exactly 9 psi. Any time the concentrator fluctuates and drops below 9psi the tank will want to push threw. But if the concentrator is trying to push say 8.5 psi in to an opposing stream its going to be hard. inless the pressure in the concentrator builds up to 9 or higher then it will be the stronger stream. But the tank would usually win because its not going to fall behind intill the tank starts to empty. and some times the pressure on any giving gauge is RELATIVE to normal air pressure on most regulators you are going to have a very slight change in the pressure of any regulator from day to day or even hour to hour as the weather changes. So to keep the 2 pressures that closely matched might be a lot of fiddling around for a lil bit of any thing back.

So in terms of it being hooked up to save tanked o2 by having the concentrator supplement the supply its not too practical.

Now on the other hand IF you want to Use tanked o2 to supplement your concentrator if it drops in pressure when you torch You could have it to provide a "BOOST" if you had the tank pressure set below the pressure of the concentrator. In theory the tank would not bleed in to the system inless the pressure in the hose dropped below the pressure set on the tank.
So say the tank is set at 7 or 8 psi and the concentrator is pushing 9 psi. the tank should not feed inless the concentrator started to fall behind on pressure.

But the easiest sure fire way to use a tank and a concentrator together is on a 2 stage torch and to run the stage thats always on like the center on a concentrator and then run your bigger 2'nd stage fire from the tanked o2. then your only using the tank while the outer tank is on and not using it at all when the 2'nd stage is off.

Now on a much larger system like an o2 generator that has much higher pressure and a holding tank. You could have a tank hooked up in such a way as to be able to have the tank add pressure to the system if it ever fell behind a certain pressure in the holding tank. BUT only because the pressures that the gen. outputs verses the much lower pressure the user is drawing off for there torch. verses the tun on and turn of pressure of the generator. Is the only reason thats doable.
Like an onsite pro4 or a pro8 for instance. they a 60 gallon holding tank. The holding tank has a pressure switch on it that is usually set to turn the generator on if the holding tank PSI falls below 45 psi and turn the gen off when the holding tank is at 60 psi.
Now let say you run your torch at 30psi. Some times if you are really rageing for a while your holding tank pressure will still fall below 45 psi if your drawing o2 out of the tank faster then the generator is making it at the moment. Depending on the torch your using.
But you could have a tank of high pressure o2 hooked in to the holding tank that is set at 29 PSI. Then if you ever where torching so hard that the tank dropped to 29psi then the tanked o2 will keep the holding tank filled to 29psi.
intill the generator build the pressure up in the tank past 29 psi. So in a situation like that if you just can't have a interruption of your o2 stream if you have times that might occasionally need the boost from the tanked o2.

There also is a way to have a tank set up so it is on a switched valve and it turns on when a switch is activated. So it switches to the tanked o2 while the gen builds the pressure back up in the holding tank.

Yes - You are the one! I searched for your post but couldn't find it and since I have a National 8m I took note of it but at the time didn't think I would go that route. Thanks :)

And Thanks Smutboy for the detailed explaination. Clarifies things to the point I doubt I'll do it...although I might experiment out of curiosity to see if there is a difference in flame quality...

My hubby works in Hydraulics...we might get to tinkering...

How, and at what point in the system, do you measure the pressure output of the oxycon (which is used as a set point for the tank regulator)?

Me

In that case he prob has forgotten more then I know about it all.



In a test situation or a repair place they useally take the pressure reading from a tap thats inside the unit right thats right by the internal regulater.

But it can also have a pressure gauge hooked up to the outlet on the out side that your hose hooks up to get a pressure reading. wich might be more closer to the actuall working pressures its putting out at the nozel.

Yes... we tap inside (not by the regulator, but just prior to the flow gage). You will get very interesting readings if tapped external at the oxycon and at the torch. Try it... very surprising to most folks. Begins to clarify what 'pressure' (a simple scalar conjugate) really is -- and isn't.

No... the reason for the question 'how & where' was the post was unclear what the oxygen tank regulator setting was really referenced to... you'd be surprised how many folks think the oxycon flow gage is a pressure gage... and it appears the poster may have used the flow gage reading as a psig measurement, and set the tank regulator "no higher"... or took a actual psig reading at the end of the hose, versus the internal oxycon tap.

Folks tend to 'see' what they expect to see... so some very strange configurations are often purported to work really well, when actually it's self-fulfilling expections only. For example, a flameworker who hooked up fish tank air pump to an oxycon and believed it was a major improvement in oxygen purity... ok... if 0.01% oxygen improvement is major... and you disregard the flame temperature cooling effects of 78% nitrogen.

Just trying to get a handle on the facts...:biggrin:

Me

I can relate to that. I see peole all the time think noise = heat if there torch is louder then anouther they think its hotter. When its just louder.

I had a check valve on my pro4 get stuck once in the bitter cold. it was causing the holding tank to fill with nitrogen. at first glance it seemd like the roch was rageing. But the delta was hardly getting a pcs of rod soft enought to bend. But boy was it loud. I know there are blowers that would swear it was a hot flame even if it took for ever to melt the glass.

I see peepol have there pressurse set so high they get the same thing going on where they are just making a lot more noise and a lot less heat but swear they are torching hotter.

I know on my redmax if I turn the o2 up past 30 psi it takes alot longer to melt the same sized pcs of glass but yet its a lot louder.

I see it with GTTs is some one is used to working on anouther torch they try to crank up the pressure to try and make the gtt run as lound as they can get it and because its stil hotter then what ever torch they used to work on they think they are gaining some thing. and have no idea how hot it really can be if they tame the pressure down a lil bit.

Its like a teen ager with some POS car that has no muffler. they think they have some fast hotrod when its just loud.

So I could see some one swearing a fish pump pumping n2 in to the mix is making there torch SEEM like its rageing when its infact cooling the flame.

Hey everyone. I am taking a lampworking class and enjoying it greatly, and I am currently toying with the idea of setting up a Carlisle Wildcat (2 valve) to a cheapo oxycon for some light to midrange boro work. I am not 100% knowledgable on all this yet, so I appologize if I say something impossible or stupid.

Can a oxycon fill up a 02 tank? It would be great if I could just get a big ass 02 tank, let a oxycon fill it up, then disconnect the oxycon from the tank, and connect the tank to the torch, lampwork away untill the tank runs out, then use the oxycon to fill it back up overnight.

I guess it would look something like this -
Oxycon --> backflow resistor --> O2 tank --> Oxygen regulator --> Torch

Anyway, sorry if this is a stupid question...thanks for the help.

-rob

No. A very good concept but here's the challenge. To get all the cubic foot of oxygen into the tank (about 270 cubic foot) it's pumped into the tank under pressure -- thus referred to as compressed gas. In fact, standard oxygen tank is very compressed gas... with a tank pressure of 2100 psig.

Unfortunately, oxycons only pump oxygen at 5 psig to 10 psig. Some of the larger models, referred to as oxygen generators, can pump out 20 psig. Still not quite enough to put much more than about 5 cubic foot in the tank before it just can't pump any more.

There are some oxycons with a 'air tank' attached where you can store a little reserve oxygen for short quick boosts... but not for running very long.

Good logic though :-D

Me

From what I've read yes, that's possible actually. You just need to buy an expensive compressor to go between the oxycon and the tank. Rix makes a microbooster that Ro uses to fill her tanks overnight. It takes longer with an oxycon versus a generator but it is definitely possible and several folks do it. I think Ro has a picture on her website of her setup, www.rosglassworld.com . Good luck!

The only thing tho is a rix compresser cost about 5 grand. More then a huge o2 genarater set up. The rix also needs maintance. a few times a year if you use it a lot. And the rix is not meant to filling a compleatly empty tank as much as its meant for topping off a tank that is not all the way full. Scuba divers use them to add nitrogen and o2 to scuba tanks for nitrox diving. But they are consided one of the lower end dive compressers by a lot of scuba divers that fill there own tanks. There considered to be POS from any reviews I have read form divers that use em.

Inless some had to have there tanks portable for taking to anouther location. and bug industral o2 gen is the way to go. for the $$

My onsite pro8 has a 60 gallon holding tank that fills up to 60psi then it shuts off. and turns back on when the tank drops to 45 psi
It makes the equivlent of a K tank worth of o2 about every 3 hours.
So I get all the o2 I and meghan can use. out of it and it don't have to be stripped down and rebuilt every few months.