How many BTUs can a 3/4-inch gas line supply?
It depends on the run length and gas type, but a 3/4-inch natural-gas line typically carries on the order of 150,000 to 200,000 BTU on a short run and falls toward 100,000 or less as the run stretches out. That's plenty for one or several fireplaces near the source — the exact number comes from a sizing table, not a rule of thumb.
The honest range
There's no single answer because capacity slides with distance. Close to the meter, a 3/4-inch schedule-40 natural-gas line moves somewhere around 200,000 BTU; stretch it out fifty to a hundred feet and that falls toward 100,000 or less. Propane changes the numbers again — it packs far more energy per cubic foot and usually runs at higher pressure, so a 3/4-inch LP line often carries more BTU than the same pipe on natural gas.
Enough for a fireplace, and then some
Since a single gas fireplace draws roughly 20,000 to 40,000 BTU, 3/4-inch is comfortable for one fireplace on almost any reasonable run — and often for a fireplace plus another appliance. That's exactly why we frequently run a 3/4-inch trunk and branch off it: headroom now, and room to add a second hearth or an outdoor line later without re-piping the whole house.
The number that matters is yours
National capacity charts are a starting point, not a spec for your home. The real figure depends on your run length, fittings, pressure, and whether the line is natural gas or propane — plus what the meter or regulator can supply upstream. We run the sizing calc for your layout, size accordingly, permit it, and pressure-test. Sizing and running gas pipe is licensed work in North Carolina, and it's ours. Call (828) 545-0525.
How we can help
Related questions
- Is a 1/2-inch gas line big enough for a gas fireplace?
- Does the length of the gas line run change what pipe size I need?
- How do I know if my existing gas line can handle a new fireplace?
- What size gas line does an outdoor fire pit or outdoor fireplace need?
- What size gas line does a gas fireplace need?
- How many BTUs per square foot do I need to heat a room with a fireplace?
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