Running a Glass Torch on Natural Gas: Conversion, House Pressure, and Boosters

Short answer: Yes, many bench torches run on household natural gas, but the deciding factor is pressure, not the torch’s willingness to burn the fuel. A house line delivers roughly 7-8 inches of water column, which is only about 1/4 PSI, while many torches publish propane pressures of 2-5 PSI. Torches that run happily at 1/4 PSI (GTT states its torches can, and Bethlehem publishes 1/4 PSI natural-gas specs for the Alpha) can work straight off a properly plumbed house line. Torches that want more fuel pressure need a booster. And the line itself is real gas plumbing: in most jurisdictions that means a permit and a licensed gas fitter, not a weekend tee-in.

This guide covers the fuel-side conversion question specifically. For the full plumbing-to-flame walkthrough, see the lampworking torch setup guide, and for the propane-or-natural-gas decision itself, see propane vs natural gas for torchwork.

Why run a torch on natural gas?

The appeal is simple: no fuel cylinders. Natural gas arrives by pipe, so there is nothing to refill, nothing to store, and no propane tank sitting outside (or worse, indoors, which fire codes and insurers generally prohibit; see home studio insurance and fire code). The fuel supply is effectively endless for a home studio, and you never lose a session to an empty tank. Scientific glassblowing shops have run on piped natural gas for generations for exactly these reasons.

The trade-offs are equally real: house-line pressure is low, the energy content per cubic foot is lower than propane, and once your torch is plumbed to the house, your studio stops being portable. The rest of this article works through each of those.

Natural gas vs propane: pressure, BTU, and orifice basics

Three differences matter at the torch:

Because natural gas carries roughly 1,030 BTU per cubic foot against about 2,516 BTU per cubic foot for propane, a torch must flow more than twice the volume of natural gas to deliver the same heat. On premix designs, that means the orifice or tip drilled for propane is too small for natural gas: the correct natural-gas tip is substantially larger. This is why premix makers sell fuel-specific tips rather than telling you to open a valve further.

The practical rules that fall out of this:

• Surface-mix torches (GTT, Carlisle CC family, Nortel surface-mix models) generally tolerate fuel switching with valve adjustment, since the gases mix at the torch face.
• Premix torches and tipped burners (National blowpipes, Carlisle premix-tipped burners, Nortel premix tops, Bethlehem premix models) need the correct tip or orifice for the fuel. Never plumb a propane-jetted premix torch to natural gas and hope the valves make up the difference.
• In every case, the manufacturer’s manual for your exact torch takes precedence over anything in this article, including which fuels are supported at all and at what pressures.

What your house line actually delivers: inches of water column, not PSI

Here is where most conversion plans hit reality. Residential natural gas piping between the meter and the appliance regulator typically runs about 7-8 inches of water column (WC), and most utilities set the meter regulator around 7” WC. Since about 28 inches of water column equals 1 pound of pressure, household natural gas arrives at roughly 1/4 PSI.

Household pressure is not a single universal number, though. Published figures for typical delivery range from about 3.5” to 8” WC, appliance regulators are variously specified at 4”-12” WC (Bethlehem’s stated range for its lever-type natural-gas regulators) or 7”-11” WC, and some homes have elevated 2 PSI systems with step-down regulators at each appliance. You will not know what your line delivers until someone measures it.

Compare that 1/4 PSI to published torch pressures:

• Bethlehem specifies the Alpha on natural gas at 1/4 PSI and 8 cubic feet per hour (8,120 BTU/hr) with oxygen at 4 PSI, and recommends a lever-type regulator controlling 4”-12” WC, which it calls standard residential pressure. On propane, the Alpha and Bravo run around 2 PSI and the Champion and Grand around 5 PSI, and Bethlehem warns never to exceed 25 PSI on any feed.
• Carlisle recommends roughly 2 PSI fuel and 5 PSI oxygen for the Mini CC and Wildcat, and 2-3 PSI fuel for the Hellcat. Those pressures are above what an unboosted house line provides.
• GTT states its torches’ fuel pressures can run as low as 1/4 PSI on natural gas or propane, which is why GTT bench torches like the Lynx and Bobcat are the usual recommendation for unboosted household lines.
• The Nortel Minor’s commonly cited operating range is about 0.25-5 PSI fuel and 5-15 PSI oxygen. That figure circulates via a hackerspace wiki mirror of the manual, so confirm it against Nortel’s printed documentation before building around it.

If a torch’s published fuel pressure is above roughly 1/4 PSI, an unboosted house line will either fail to run it or run it well below its rated output.

Which torch makers support natural gas

Natural-gas support is broad across the major bench-torch makers. The load-bearing question is almost always pressure, covered above, plus the correct tip on premix designs.

• GTT (Glass Torch Technologies). Surface-mix line, and the maker that explicitly states 1/4 PSI operation. The strongest fit for a straight house-line hookup, from the Cricket up through larger torches, with the caveat below about big torches and output.
• Bethlehem Burners. The Alpha is designed to burn natural gas, hydrogen, propane, or butane, and Bethlehem publishes actual natural-gas pressure and flow specs plus a WC-range regulator recommendation. That published data makes Bethlehem unusually easy to plan around.
• Carlisle Machine Works. The CC runs on oxygen with natural gas, propane, or hydrogen, with different tips suggested depending on the gas. On Carlisle’s premix-tipped burners, the natural-gas conversion is a tip/orifice change, not a valve tweak. Published fuel pressures around 2 PSI mean Carlisle burners typically want a booster on household lines.
• Nortel. Surface-mix torches accept natural gas, propane, or hydrogen. The Minor’s cited 0.25 PSI floor suggests house-line operation is possible at reduced output, with full range available under higher pressure.
• National (Premier Industries). The 3A-B and 3B-B premix hand torches are a decades-old scientific-glassblowing standard and run natural gas, propane, or butane with oxygen or compressed air by selecting the proper torch tip. The 3A-B and 3B-B differ only in hose fitting.

One catalog honesty note: natural-gas support is common but not universal. Herbert Arnold’s hand-torch entries in our catalog, for example, list propane only. Check the maker’s documentation for your specific model rather than assuming.

When you need a booster (and when house pressure is enough)

A torch booster is a purpose-built appliance that mechanically compresses utility natural gas to torch-friendly pressures. G-TEC, the main manufacturer in this niche, states that most lampworking artists prefer fuel gas at 5-10 PSI while utility pressure is often under 1 PSI, and its Torch Boosters raise utility gas to 5-25 PSI. Sizing is by flow: the TB-15 (15 cubic feet per hour) is sized for Minor-class torches, the TB-30 for mid-range torches, and the TB-60 and TB-125 for major torches and classrooms.

Keep two caveats in mind. First, the “most artists prefer 5-10 PSI” framing comes from a company that sells boosters. It is broadly consistent with Carlisle’s and Nortel’s published pressures, but GTT torches demonstrably run at 1/4 PSI, so “you need a booster” is torch-dependent, not universal. Second, G-TEC’s marketing claims about natural gas being far cheaper than propane and giving cleaner flames vary by region and utility rate; treat them as claims, not facts.

A rough decision guide:

Two things never to do: do not improvise a booster from an air compressor or any device not built for fuel gas, and never tamper with the utility’s meter regulator. Booster installation may itself need utility or local-authority sign-off, so fold it into the permit conversation below. If your flame behaves oddly after a natural-gas hookup, low supply pressure and regulator mismatch are prime suspects; see regulator troubleshooting.

Plumbing, permits, and who is allowed to run the line

This is the part of the conversion people most want to skip, so here is the honest version. Fuel-gas piping in the US is governed by NFPA 54 / ANSI Z223.1, the National Fuel Gas Code, which covers design and installation of natural-gas piping up to 125 PSI. Under it, and under the local codes that adopt and amend it:

• Most jurisdictions require a permit before gas piping work.
• The work generally must be done by a “qualified agency”, meaning a gas fitter licensed or registered with your local authority having jurisdiction (AHJ).
• Piping is sized from code tables based on total demand in cubic feet per hour and run length, upsizing at branches as needed. A torch branch line is a sized, permitted appliance drop, not an ad-hoc tee off the nearest pipe.

Requirements vary by jurisdiction, and NFPA 54 picks up local amendments (Massachusetts’ 248 CMR is a well-known example), so the practical advice is: call a licensed gas fitter, and let them pull the permit. Beyond legality, this ties directly into insurance. Unpermitted gas work is exactly the kind of thing that can void a homeowner’s policy after an incident; the home studio insurance and fire code guide covers that conversation in detail.

Pros and cons: endless fuel vs a fixed, lower-pressure studio

Key takeaways

• Pressure is the whole game. House lines deliver about 7-8” WC, roughly 1/4 PSI. Torches specified at 1/4 PSI (GTT’s stated floor, Bethlehem’s Alpha NG spec) can run unboosted; torches published at 2-5 PSI (Carlisle, Bethlehem’s larger burners on propane) need a booster for rated performance.
• Premix means new tips. Natural gas carries ~1,030 BTU per cubic foot vs ~2,516 for propane, so premix and tipped burners need the correct, larger natural-gas orifice. Surface-mix torches tolerate fuel switching with valve adjustment.
• Boosters are sized by flow (G-TEC’s TB-15 through TB-125), and the need for one is torch-dependent, not universal.
• The line is real gas plumbing. NFPA 54 applies, most jurisdictions require a permit and a licensed fitter, and unpermitted work can haunt your insurance.
• Your manufacturer’s manual wins. Every pressure figure here is a published range for planning; confirm fuels, pressures, and tips for your exact torch with the maker before connecting anything.

Sources

• Bethlehem Burners, “Technical Information” (NG/propane pressures, regulator ranges): https://www.bethlehemburners.com/resources/technical-information/
• Carlisle Machine Works, “CC Bench Burner” (fuels and tip selection): http://carlislemachine.com/as_benchburners/cc.php
• Glass Torch Technologies, FAQ (1/4 PSI fuel operation): https://www.glasstorchtech.com/faq
• G-TEC, “Torch Boosters” (booster pressures and sizing): https://www.gas-tec.com/torch-boosters
• NFPA, “NFPA 54: National Fuel Gas Code”: https://www.nfpa.org/codes-and-standards/5/4/nfpa-54
• InspectApedia, “Gas Pressures” (residential WC figures): https://inspectapedia.com/plumbing/Gas_Pressures.php
• Hive13 wiki, “Nortel Minor Torch” (manual mirror; confirm against printed manual): https://wiki.hive13.org/view/Nortel_Minor_Torch
• National Torch (Premier Industries), 3A-B/3B-B blowpipes: https://nationaltorch.com/?page_id=301

Editor’s note: pressure and flow figures above are published manufacturer and reference values as of 2026, and sources disagree on “typical” household delivery (3.5”-8” WC) and appliance-regulator ranges (4”-12” WC per Bethlehem, 7”-11” WC elsewhere). The Nortel Minor figures come from a community mirror of the manual. Always follow your torch manufacturer’s instructions, your gas utility, and your local code and fitter over anything here.