GTT Bobcat on 2 oxycons

earth*monkey · #1 2006-11-22, 11:17am

Hey all,

So I hooked up two oxycons to my bobcat, and now I'm thinking I have too much oxygen.

The flame is very nice, but I noticed that the pressure dropped down to about 3 - 3 1/2 on each oxycon. With one, I ran the oxy button all the way open. Now, if I run it too open it's really loud. It has that oxy hiss.

Do I need to do anything with the pressure on the propane tank?

Is anyone running two oxycons with a bobcat? Any advice?

kbinkster · #2 2006-11-22, 11:39am

What you are seeing is the flow meter reading the flow.

Two oxygen concentrators (combined 10 LPM) provides more oxygen than the Bobcat needs to operate. So, at a normal flame, you should not expect to see both concentrators (or a single larger one) to read the maximum on the flow meter.

Having a flow readout of less than 5 LPM per machine (or 10 LPM on a larger unit) is fine. Having a readout above the 5 LPM mark per machine (or above the 10 LPM mark on a larger unit) is not good and should be avoided.

Here is what I did with my old 10 LPM concentrator to avoid that (on my new one, it doesn't matter):

I open the oxygen valve all the way on the torch.
I turn on the concentrator (in your case, two concentrators) and let it run.
I adjust the flow on the concentrator to 10 LPM (in your case, you would adjust it to 5 LPM on each concentrator)
I turn off the oxygen at the torch just long enough to light it and get a propane flame about 6"-7" long.
I then turn on the oxygen valve at the torch and add oxygen until I get a hiss.
Then, I turn the oxygen valve at the torch back down until the hiss goes away.

As you adjust your torch, the flow meter reading will change up and down. But, by doing it the way I just described, it will never go above the intended flow for that machine.

As for your propane setting, you can keep that where it is unless you are having problems with the propane. The Bobcat runs on low pressure (like 1/4 psi), but you can run it on 5 psi to avoid fluctuations with the regulator.

Oh, keep in mind that some people run their torches on concentrators with the oxygen valve wide open, making all the oxygen adjustments with the concentrator flow knob. I don't do it that way. I use the torch valve to control the flow into the torch - keeping in mind that if I need to shut off the torch, I cannot keep the oxygen valve closed while the concentrator is running (this is true of all the oxygen concentrators with the exception of the Regalia). If I have to take a break and don't want to shut off the machine, I leave it running, turn off the torch, and then open the oxygen valve back up at the torch.

Chuckie · #3 2006-11-22, 11:41am

PM Shawnette (Glassgoodies) and ask her how she fixed her problem. Her concentrators did the same thing. She added some backflow valves to the oxy lines to prevent the additional pressure from being read by the oxycon sensors. The increased pressure causes the pumps to adjust to a lower output.

kbinkster · #4 2006-11-22, 11:44am

If your two concentrators are putting out the same psi, and you are running the same LPMs on both, then you do not need the backflow devices. If they are not, then it is a good idea to put them on your connector (if your connector doesn't already have them). I sell them if you need them.

meister1981 · #5 2006-11-23, 7:18am

I have a quick question for Kimberly about the flow meter and oxy con. How is it that you should not go higher then 5 LPM when the maximum reading on the flow meter is 5 LPM and the machine is rated to produce a maximum of 5 LPM. I'll compare it a little to an air compressor which if it produces a maximum of 110PSI I can crank the knob more but I won't get more PSI and CFM then the compressor is good for. So how is it that we can ask the concentrator for more oxygen then the unit is good for? Maybe it's just me but I'm not getting the concept of being able to pull out more oxygen out of the machine that it can produce itself.

bhhco · #6 2006-11-23, 8:42am

Quote:

Originally Posted by meister1981

...Maybe it's just me but I'm not getting the concept of being able to pull out more oxygen out of the machine that it can produce itself.

An 5 LPM oxycon is rated for 5 LPM flow. An oxycon is rated at the maximum flow that still produces 'good' oxygen purity -- not it's maximum flow capabilty.

A 5 LPM rated oxycon can flow more than 5 LPM. You can turn the flow control up past the 5 LPM mark, until the little ball pegs out at the top of the flow meter (and more)... and you will be flowing more than 5 LPM. But you will not like the result, because the oxygen purity will fall off dramatically when the oxycon's rated LPM is exceeded.

Me

earth*monkey · #7 2006-11-23, 9:38am

Thanks for the thorough reply Kimberly. This is super information. I'm off to make some adjustments.

kbinkster · #8 2006-11-23, 10:20am

You're welcome, Lara.

Quote:

Originally Posted by meister1981

I have a quick question for Kimberly about the flow meter and oxy con. How is it that you should not go higher then 5 LPM when the maximum reading on the flow meter is 5 LPM and the machine is rated to produce a maximum of 5 LPM. I'll compare it a little to an air compressor which if it produces a maximum of 110PSI I can crank the knob more but I won't get more PSI and CFM then the compressor is good for. So how is it that we can ask the concentrator for more oxygen then the unit is good for? Maybe it's just me but I'm not getting the concept of being able to pull out more oxygen out of the machine that it can produce itself.

Emmanuel, Bill provided an excellent explanation (Thank you, Bill.

).

I will add to it, though, the other "why" you should not push a 5 LPM machine over 5 LPM (or a 10 LPM machine over 10 LPM, etc.) or above the manufacturers recommended output pressure (and before you ask, yes, there is a way to increase the output pressure of the machine) besides poor purity. It will shorten the life of the machine.

When you are pushing the machine harder than it is rated for, you are pushing more air through the seive beds than was intended. The result is that the seive material starts to break down into a "sand." This material travels to your torch and can clog up the valves of your torch.

Someone who is brand new to an oxygen/fuel set-up may not even know that they are getting poor purity when the ball of the flow meter is over the 5 LPM mark. And, by the time they notice a problem at the torch (from the torch valves being clogged), the damage has already been done to the machine.

meister1981 · #9 2006-11-23, 4:04pm

Ok thank you for the explanations. I just don't get why they don't just limit the machines so that improper use is not possible and will prevent breakage or shorten the life of the unit.

kbinkster · #10 2006-11-23, 5:13pm

Quote:

Originally Posted by meister1981

Ok thank you for the explanations. I just don't get why they don't just limit the machines so that improper use is not possible and will prevent breakage or shorten the life of the unit.

Actually, SeQual does just that with the Regalia (10 LPM machine). Instead of the traditional external flow meter and dial, it has a touch pad control panel with a digital readout. You just set the flow, and it stays there. No matter how you run the torch, or even if you shut the torch off, the flow remains constant (no fluctuations at all) and you can never set it above the limit.

ETA: No more watching the bouncing ball!

e. mort · #11 2006-11-23, 8:40pm

Kimberly, are you going to Tucson this year, and if so are you going to have the regalia set up for the Lynx so we can try it out? I would really like to try some small boro on that setup.

Eric

kbinkster · #12 2006-11-24, 11:01am

Quote:

Originally Posted by e. mort

Kimberly, are you going to Tucson this year, and if so are you going to have the regalia set up for the Lynx so we can try it out? I would really like to try some small boro on that setup.

Eric

I hadn't planned on it, Eric. The last Tucson show I went to (with Willy in '05) did not have it set up where you could run torches. I wasn't there this year, so I don't know if they brought that feature back. If they have, then I might be interested in going.

Justin L · #13 2006-11-24, 1:31pm

Quote:

Originally Posted by kbinkster

When you are pushing the machine harder than it is rated for, you are pushing more air through the seive beds than was intended. The result is that the seive material starts to break down into a "sand." This material travels to your torch and can clog up the valves of your torch.

If your sieve beds do start to break down due to abuse, the broken down powder should NEVER be able to be pumped out of the machine if all filters are in place. If you notice this powder coming out of the oxygen outlet, the machine needs to be returned to have the filters replaced, and make sure that something isnt hooked up wrong, or any safety measures were removed from the machine to make it for "Hobby Use".

It IS however, able to be pushed out the EXHAUST MUFFLER and it may exit out the bottom/base of the machine, but should NEVER come out of the oxygen output.

kbinkster · #14 2006-11-24, 2:39pm

Quote:

Originally Posted by Justin L

If your sieve beds do start to break down due to abuse, the broken down powder should NEVER be able to be pumped out of the machine if all filters are in place. If you notice this powder coming out of the oxygen outlet, the machine needs to be returned to have the filters replaced, and make sure that something isnt hooked up wrong, or any safety measures were removed from the machine to make it for "Hobby Use".

It IS however, able to be pushed out the EXHAUST MUFFLER and it may exit out the bottom/base of the machine, but should NEVER come out of the oxygen output.

I was citing a worst-case scenario. Perhaps instead of saying "it will," I should have said, "under certain circumstances, it could (and has)."

The point that I hope is not lost is that the machines can become damaged when run above the recommended pressure and flow outputs. If the machine is run correctly, then there should not be a problem. Having filters in place does not ensure that the machine is being run correctly and does nothing to prevent the damage to the seive material. That is up to the person running the unit.

Believe it or not, there are people who remove filters and/or increase the pressure output on their machines to try to get better performance. Those machines are out there and some may eventually find their way onto eBay.

This is another good reason for buying a used concentrator from a reputable company that offers fully reconditioned concentrators. A fully reconditioned unit will have repoured seive beds, rebuilt valves and compressor, will have been cleaned and disinfected, and will have all new filters.

And, just to point something out... I sell both new and reconditioned oxygen concentrators "for Hobby/Industrial Use Only" because I am not in the medical supply business. My focus is lampworking. My supplier for the reconditioned oxygen concentrators is a reputable medical supplier, though (for nearly 30 years), and the units I buy from them have been fully reconditioned. The new unit that I sell (the Regalia) was designed by the manufacturer specifically for lampworking and not for medical use.

e. mort · #15 2006-11-24, 3:57pm

Where can a person go to "test drive" the Regalia and other concentrators. I heard that they were set up at an ISGB or GAS event, but I am not sure where. Due to disappointments with other equipment in the past (not glass related) I have become a big fan of the "test drive", and will usually only purchase equipment that I have been able to try out.

Eric

kbinkster · #16 2006-11-24, 4:31pm

Quote:

Originally Posted by e. mort

Where can a person go to "test drive" the Regalia and other concentrators. I heard that they were set up at an ISGB or GAS event, but I am not sure where. Due to disappointments with other equipment in the past (not glass related) I have become a big fan of the "test drive", and will usually only purchase equipment that I have been able to try out.

Eric

The Regalia was set up at the ISGB Gathering this summer. Willy and I ran it at the GTT table for Open Torch (this was before Paulette handed the business over to me). At the very least, I plan to be at the next Open Torch. If I can get a SeQual rep to come, too, I will.

meister1981 · #17 2006-11-24, 9:55pm

I was looking at the regalia on your site Kimberly and headed over to SeQual's website to see about this machine. I noticed that the Regalia isn't on their website but the Integra E-Z 7 and 10 were. After looking at the picture the Regalia look identical to the Integra E-Z and everything mentionned about the Regalia is mentionned on the Integra E-Z description except for the Lampworking part. I was wondering whet the difference was between both or should I just write to Sequal so that they can telle me the specifics? Looks like a very good machine all in all

kbinkster · #18 2006-11-24, 11:41pm

The biggest difference between the Integra10 EZ and the Regalia is that they have different software installed. The Regalia won't alarm when you turn the oxygen off at the torch. This allows you to use your torch just like you would if you were using a tank. The "guts" of the machines are the same - they both use the same patented ATF module.

SeQual also makes a Regalia that runs on 220V/50Hz. It is just a little bit more expensive than the 110V/60Hz model.

meister1981 · #19 2006-11-27, 6:42am

Ok and the back pressure from turning off the oxygen at the torch won't hurt the concentrator at all? The second model is for europe since it's 220v/50Hz and it won't work here without a proper converter.

Is there a reason they don't have the regalia up on their website just for information at least for people looking for it?

kbinkster · #20 2006-11-27, 10:19am

Quote:

Originally Posted by meister1981

Ok and the back pressure from turning off the oxygen at the torch won't hurt the concentrator at all? The second model is for europe since it's 220v/50Hz and it won't work here without a proper converter.

Is there a reason they don't have the regalia up on their website just for information at least for people looking for it?

That's right, the 220V/50Hz model is for Europe and Australia. I was under the impression that Canada has the same electrical as the U.S.

SeQual probably doesn't have the information up for the Regalia on their website right now because it is so new and I, at least, have it up on mine. I am the sole distributor of the Regalia for the Lampworking industry. If you have any questions that are not answered on my website, I will be happy to answer them for you. I do intend to update my website, soon, though.

And to answer your question about back pressure, turning the oxygen off at the torch will not hurt the machine at all.