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GTT Phantom Oxygen Requirements: LPM, PSI, and Supply

GTT Phantom oxygen requirements from GTT's own flow chart: LPM and psi at full flame, center-fire work on a concentrator, and when tanks are the answer.

By Joe Blanchard, sixteen years on the distribution side of the glass industry · Updated

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Short answer: GTT’s own flow rate chart puts the GTT Phantom at 35 CFH of oxygen at 35 psi at its largest usable flame on propane, which converts to ~16.5 LPM. That is a ceiling, not a working average, and GTT publishes no minimum oxygen figure for the Phantom. The practical reading: one 10 LPM concentrator cannot feed the Phantom’s full two-stage flame, and the chart’s oxygen pressure sits above concentrator territory, so running the whole torch wide open is a job for tanks or bulk oxygen. Running the center fire alone is a different story. The Phantom’s center is the Lynx head, and the Lynx’s own full-flame figure, ~9.5 LPM, is within reach of a single capable concentrator.

This page is about one torch. For the general method of sizing oxygen to any torch, start with how many LPM does my torch need; for the supply decision itself, see oxygen concentrator vs tanks for lampworking.

What GTT’s chart says about the Phantom

Glass Torch Technologies publishes a flow rate chart covering its torch line. For each model it lists fuel and oxygen consumption, in cubic feet per hour (CFH), at the largest usable flame on propane, along with the fuel and oxygen pressures that go with that flame. The Phantom’s row reads as follows.

Chart item (propane, largest usable flame)GTT’s figureIn liters per minute
Oxygen flow35 CFH~16.5 LPM
Oxygen pressure35 psi(pressure, not flow)
Fuel flow12 CFH5.5 LPM as GTT prints it
Fuel pressure10 psi(pressure, not flow)

The chart prints both units. CFH multiplied by 0.4719 gives LPM, so 35 CFH of oxygen is about 16.5 LPM, matching the chart; 12 CFH of propane works out nearer 5.7 LPM than the 5.5 GTT prints, because GTT rounds its figures. Our catalog carries the oxygen number as the Phantom’s estimate and labels it that way on the torch page.

Three things about these figures matter more than the figures themselves.

  • They describe the biggest flame the torch makes, with both stages lit and opened up. They are the top of the range, not what the torch draws on a typical bead of work.
  • They are propane figures. Natural gas changes the picture (see below).
  • There is no bottom number. GTT publishes no minimum oxygen figure for the Phantom, so we do not print one, and you should be skeptical of anyone who quotes a precise “idle” LPM for it.

Why the Phantom wants more than the Lynx: the second stage

The Phantom has 22 jets across 2 stages. GTT’s Phantom page describes it as the Lynx 7-jet head used as the center fire, with a ring of 15 jets around it as the outer fire. Seven plus fifteen is the whole count; there is no hidden third ring.

That structure is the key to its oxygen behavior. With only the center lit, you are running a GTT Lynx head. With the outer ring lit as well, you are feeding fifteen more jets on top of it, and the chart figure for the Phantom reflects everything open at once. Stated side by side:

  • Lynx full flame: ~9.5 LPM, from the Lynx’s own row in GTT’s chart.
  • Phantom full flame: ~16.5 LPM, from the Phantom’s row.

Be careful with the first number. It is the Lynx’s own chart value; GTT’s chart has no separate row for the Phantom running its center alone. The center hardware is the same design, which makes it the most honest planning figure available for center-only work, but it is an inference from the Lynx, not a Phantom spec. The full family comparison lives in GTT Lynx vs GTT Phantom.

GTT also sells a Phantom hand torch with a thumb switch for the outer flame, which makes the two modes explicit: the center burns on its own, and the thumb brings the ring in when the work needs it. The bench Phantom lists at $1,425 on GTT’s store; the hand torch, the variable-switch and the compressed-air configurations are priced separately, so check GTT for the version you want.

Center fire versus full flame, in supply terms

Most buyers asking about Phantom oxygen are really asking one question: can I run this on what I have? The answer splits cleanly by how you intend to use the torch.

Center fire only. If most of your time is detail and small work on the center, and you light the outer ring rarely, your oxygen demand looks like a Lynx. A single capable concentrator is a realistic supply for that use. Keep some headroom: a concentrator pushed to its rated ceiling tends to deliver lower purity and a less steady flame, which the concentrator vs tanks guide covers in detail.

Outer ring lit and opened up. This is the reason people buy a Phantom, and it is where one concentrator runs out. ~16.5 LPM is more than a 10 LPM unit’s rating before you account for any purity sag near the top. The flame does not simply get smaller when it is short of oxygen; it gets lazy and unstable, and the torch gets blamed for a supply problem.

Somewhere in between. Plenty of work lives here: ring lit, but not wide open. The chart cannot tell you where your flame sits on that range, because GTT publishes only the top. The safe way to plan is to size for the flame you expect to run at its biggest, not the flame you run most often.

Concentrators versus tanks for this torch

Flow is only half of it. The chart pairs the Phantom’s largest flame with 35 psi of oxygen, and that is above concentrator territory. Concentrators are low-pressure machines, and plumbing several together in parallel adds their flow, not their pressure (how many LPM does my torch need walks through why). So a bank of concentrators can close the flow gap for a lot of Phantom work, but it does not reproduce the pressure GTT lists for the full flame.

That gives a plain rule of thumb for this model:

  • Center-fire work, occasional ring: one capable concentrator, with headroom.
  • Regular two-stage work below full flame: multiple concentrators in parallel can serve, with the pressure caveat above. Watch the flame, not the gauge; a soft, fluttering ring is the sign the supply is behind.
  • Full flame, wide open, for long sessions: compressed tanks or bulk oxygen, which deliver both the flow and the pressure the chart describes.

If tanks are the answer, the logistics (leasing, exchange programs, cylinder sizes, what fills cost) are in oxygen for lampworking: tanks, suppliers, and real costs. Budget for the oxygen system along with the torch; for many buyers it is the larger decision.

Pressure, regulators, and flashback protection

On tanks, the regulator sets the pressure the torch sees, and GTT’s chart gives you the pressures that pair with the largest flame: 10 psi fuel and 35 psi oxygen on propane. GTT’s instruction sheet for the Delta, Mirage and Phantom gives the same 10 and 35, and adds that a minimum of 5 psi fuel and 10 psi oxygen gives reduced results. That second line is the closest GTT comes to describing a Phantom run below its full-flame pressures. Follow GTT’s manual for your setup; the manufacturer’s instructions take precedence over any figure on this page.

Flashback protection depends on the torch and on the supply, so fit what those two call for rather than a blanket rule. The Phantom is a surface-mix torch, and GTT’s flashback arrestor page makes two points that matter directly for a Phantom owner:

  • GTT’s arrestors need roughly 5 to 7 psi to open. On a low-pressure supply they may not open properly, and they restrict flow.
  • An arrestor does not belong on an oxygen concentrator’s output. GTT’s instruction for a concentrator setup is an arrestor on the fuel source, with a flame arrestor as the low-pressure device.

That second point is worth checking if you run the Phantom’s center on a concentrator and the flame seems starved: a conventional arrestor in the oxygen line is one of the first things to question. The fuller picture, including where arrestors sit and what each position protects, is in flashback arrestors explained.

Natural gas changes the numbers

The Phantom runs on propane or natural gas, and GTT’s chart is written for propane. GTT notes that natural gas consumption runs about 2.5 times the propane figure, so the propane numbers above do not transfer directly to a natural gas studio. We do not publish a natural gas conversion of the Phantom’s chart row, because GTT does not give one per model; if you are plumbing the Phantom to natural gas, ask GTT for the figures that apply to your setup before you size the supply.

Editor’s note: the oxygen and pressure figures here come from GTT’s own flow rate chart at the largest usable flame on propane, converted to LPM by us (CFH x 0.4719). They are a ceiling, not a working requirement, and GTT publishes no minimum for the Phantom. The center-fire figure is the Lynx’s own chart value, used as a planning estimate, not a Phantom measurement. Confirm the current spec and setup pressures with GTT before you buy a torch or an oxygen system around them.

Sources

About the author

Written and edited by Joe Blanchard, who spent 2007 to 2023 on the distribution side of the glass industry in Asheville, North Carolina. GlassTorches.com is his independent, manufacturer-first buyer's guide. More about the editor.

How this guide was sourced: figures come from the manufacturer's own pages and manuals where we have them and are labelled as estimates where they are ours; the catalog on this site is the source of truth, and where sources disagree the guide says so. Confirm the current spec with the maker before you buy. How we work.