Short answer: Yes, a Bethlehem Bravo will run on one 10 LPM oxygen concentrator, but not at the flame Bethlehem’s published oxygen figure describes. Bethlehem states that the Bravo can operate on oxygen concentrators at 7 psi, and that is the maker’s own permission to do it. Bethlehem also lists the Bravo’s full-flame consumption as 30 LPM of tanked oxygen (our catalog carries it as ~30 LPM). One 10 LPM machine is a third of that number, so on a single concentrator expect a reduced flame: the center fire and a soft, throttled outer fire, rather than both stages opened all the way. That is plenty for smaller soft glass and boro work, and it is the wrong setup if you bought the Bravo to run its full two-stage flame all day.
This article is the Bravo-specific version of a general question. For how oxygen demand works on any torch, read how many LPM does my torch need; for matching a concentrator to a torch, the oxygen concentrator LPM guide is the sizing layer. Here we stay with one torch, one machine, and what the numbers do and do not say.
What Bethlehem publishes about the Bravo’s oxygen
It helps to separate what Bethlehem actually says from what anyone, including us, works out from it. Bethlehem’s statements about the Bravo come in two places, the product page and the operating instructions, and they amount to four facts:
- Full-flame consumption on tanked oxygen. The product page lists tanked oxygen at 8 to 20 psi and 30 LPM. That is what the torch burns with both stages at full flame on cylinder oxygen. It is a ceiling, not a minimum.
- Full-flame gas. The same page lists 6 LPM of gas at full flame.
- Concentrators at 7 psi. Bethlehem states the Bravo can also operate on household gas at 1/4 psi and on oxygen concentrators at 7 psi. No flow figure is attached to that statement.
- No minimum. Bethlehem publishes no minimum oxygen flow for the Bravo, and no split of the 30 LPM between the center fire and the outer fire.
Everything past those four lines is arithmetic or judgment. The torch itself is a two-stage surface-mix bench burner with 18 jets: Bethlehem describes two independent burners in one barrel, a 6-jet center fire inside a 12-jet outer fire on a 1 inch face, each with its own gas and oxygen valves. That layout is the reason a single concentrator is workable at all, because you can run the center fire on its own or bring the outer fire in gently, instead of feeding one large flame that is either on or off. The Bravo replaced the discontinued Barracuda in Bethlehem’s line, and it ships with a swivel base and scroll pedestal.
What one 10 LPM concentrator buys you
Start with the plain division. Ten is a third of thirty, so a machine that genuinely delivers 10 LPM supplies about a third of the oxygen Bethlehem lists for the Bravo at full flame on tanks. That much is arithmetic on Bethlehem’s own figure, and it is the whole reason for the answer above.
What that third looks like at the bench is less precise, and we will not dress it up. Bethlehem’s 30 LPM covers the Bravo at full flame as a whole, not stage by stage, so nobody can tell you from it that 10 LPM runs the center fire wide open with a set amount left over for the outer ring. What you can say honestly is the shape of it: a concentrator-fed Bravo is run as a smaller torch. You light the center fire, work with it, and open the outer fire as far as the oxygen lets the flame stay clean and stable. Push past that point and the flame tells you, going lazy, long and soft instead of tight, which is the oxygen-starved behavior described in how many LPM does my torch need.
One more thing shrinks the effective number. A concentrator’s rating is its ceiling, and purity tends to sag as a machine is pushed toward that ceiling, which the oxygen concentrator LPM guide covers with the community figures and their caveats. So “10 LPM” on the label is the best case, not a steady 10 LPM of high-purity oxygen at the torch. Plan with a little headroom rather than assuming the rating.
For comparison inside Bethlehem’s own line, the single-stage Alpha is listed at ~10 LPM full flame, and Bethlehem calls it ideal for a concentrator at 7 psi (Alpha product page). On paper, one 10 LPM machine meets the Alpha’s whole published full-flame figure and a third of the Bravo’s. That is the honest trade: the Alpha ($350) is sized to one machine, while the Bravo ($1,171) is a bigger torch you can run small. The Alpha vs Bravo vs Champion comparison walks through the rest of the difference.
The 7 psi figure and the pressure question
The 7 psi line matters as much as the flow number, and it is easy to misread. Bethlehem gives two operating points for the Bravo: tanked oxygen at 8 to 20 psi with the 30 LPM full-flame figure, and concentrators at 7 psi with no flow figure. Note that 7 sits just below the bottom of that tanked range. That is a comparison of Bethlehem’s two numbers, not a statement from Bethlehem about how much flame you get at 7 psi, and we are not going to invent one.
What it does tell you is that Bethlehem expects the Bravo to see lower oxygen pressure on a concentrator than on a regulated cylinder, and still considers that a supported way to run it. It does not tell you what pressure your particular concentrator delivers. That depends on the machine, so read its own spec plate or manual rather than assuming it reaches 7 psi. If your unit’s published output pressure is below what Bethlehem names, that is a question for Bethlehem and for the concentrator’s maker before you plumb it, not something to guess at. The Bravo’s operating instructions take precedence over anything written here.
Two or three concentrators in parallel
The usual way a home studio grows past one machine is to plumb two or more in parallel. That adds flow, not pressure: two 10 LPM machines give you about 20 LPM of combined flow, at roughly the pressure of one machine, as how many LPM does my torch need explains. If you are choosing machines for a stack, oxygen concentrator brands compared covers the models lampworkers use.
Run that against Bethlehem’s figure and the picture changes in steps:
| Oxygen supply | Flow against the Bravo’s 30 LPM full-flame figure | What it means in practice |
|---|---|---|
| One 10 LPM concentrator | About one third | Center fire plus a soft outer fire; a smaller Bravo |
| Two 10 LPM in parallel | About two thirds | More outer fire; pressure still one machine’s |
| Three 10 LPM in parallel | Equal on paper | Flow meets the figure; pressure and purity at the ceiling still limit it |
| Tanked oxygen at 8 to 20 psi | Bethlehem’s own full-flame condition | The flame the 30 LPM describes |
The ratios in the middle column are our arithmetic on Bethlehem’s number and the concentrators’ rated flow. The third row is the one to be careful with. Three machines match 30 LPM only if each delivers its full rating, which is exactly where purity is lowest, and parallel plumbing never lifts the pressure above what the machines produce. It is a real option for more flame without cylinders, but “matches on paper” is not the tanked full flame.
When tanks make sense for a Bravo
Bethlehem’s 30 LPM figure is written for tanked oxygen, so cylinders are the supply that reproduces the flame Bethlehem is describing. If your work regularly calls for both stages opened up, larger boro within the Bravo’s small-to-medium range, or long sessions at a big flame, tanks are the straightforward answer, and a concentrator stack becomes a compromise you are paying for in machines, power and noise.
If your work mostly lives in the center fire, a concentrator is a reasonable way to run a Bravo, and plenty of buyers choose the Bravo precisely because it scales: small on one machine now, bigger on more oxygen later. The trade-offs between the two supplies (refills, handling, power, running cost) are laid out in oxygen concentrator vs tanks for lampworking. If you are still choosing between the Bravo and a smaller detail torch, the GTT Lynx vs Bethlehem Bravo comparison covers how differently those two torches draw oxygen.
Fuels, and what they change
Bethlehem’s operating instructions list natural gas, hydrogen, propane and butane for the Bravo, and the product page’s full-flame line pairs 6 LPM of gas with 30 LPM of oxygen. Different fuels burn with different amounts of oxygen for the same flame, so your fuel moves the oxygen side of the equation, and that single full-flame pair is the only Bravo consumption figure in our sources. If you size a concentrator setup around a particular fuel, ask Bethlehem what oxygen it calls for on the Bravo first, and light and adjust the torch the way the operating instructions describe.
Flashback protection on a concentrator setup
Bethlehem’s stated position, in its Alpha operating instructions, is that its surface-mix burners do not require a flashback arrestor while premix torches do, subject to local regulation. The Bravo is surface mix, like every Bethlehem burner. That is the maker’s position about its own torches, not a blanket rule for every setup, and your local code can require more.
Concentrators add one wrinkle worth knowing before you buy hardware: GTT, for its own torches, advises against putting a conventional arrestor on a concentrator’s output, because the device restricts a low-pressure flow you are already short on. That is another maker’s guidance, not Bethlehem’s, but the physics of a low-pressure line is the same. The right framing is always the flashback protection your torch and gas supply call for, and flashback arrestors explained sets out what the makers say and where each device goes.
Editor’s note: every Bravo figure here (30 LPM tanked oxygen at 8 to 20 psi, 6 LPM gas at full flame, concentrator operation at 7 psi) comes from Bethlehem’s own product page and operating instructions as captured in our catalog in 2026. The fractions and the parallel-concentrator math are our arithmetic on those figures and on a concentrator’s rated flow, not Bethlehem’s statements. Concentrator output and purity vary by machine. Confirm the current spec and your setup with Bethlehem before you buy.
Related guides
- How many LPM does my torch need
- Oxygen concentrator LPM guide
- Oxygen concentrator vs tanks for lampworking
- GTT Lynx vs Bethlehem Bravo
- Flashback arrestors explained
Sources
- Bethlehem Burners, “Bravo”: https://www.bethlehemburners.com/torches/bravo/
- Bethlehem Burners, “Bravo Operating Instructions”: https://www.bethlehemburners.com/resources/operating-instructions/bravo-operating-instructions/
- Bethlehem Burners, “Alpha”: https://www.bethlehemburners.com/torches/alpha/
- Bethlehem Burners, “Alpha Operating Instructions”: https://www.bethlehemburners.com/resources/operating-instructions/alpha-operating-instructions/
- Glass Torch Technologies, “Flashback arrestors”: https://www.glasstorchtech.com/flashback-arrestors