Flare vs. combustor vs. enclosed combustor: what's the difference?

Flare, combustor, enclosed combustor — operators use these words loosely, and the salesman's brochure doesn't always help. They all do the same basic thing: burn off gas you can't sell, reinject, or capture. The differences are in how completely they burn it, how visible the flame is, and what your jurisdiction will sign off on.

Flare (open flame)

The classic candlestick or utility flare — an open flame at the tip of a stack. Simple, high-capacity, and proven. The downside is that an open flame's combustion efficiency depends on wind, gas composition, and assist, and it's harder to prove a specific destruction efficiency. It's also visible for miles, which isn't always welcome near roads or homes.

Combustor / enclosed combustor

A combustor burns the gas inside a refractory-lined enclosure (sometimes called a ground flare). The flame isn't visible, the combustion happens in a controlled environment, and these units are designed to hit high, consistent combustion efficiency — typically 98%+, which is what most modern emissions rules are written around. For a lot of Permian sites near anything populated, an enclosed combustor is the practical choice.

So which one do you need?

• Volume. Big, variable volumes often still go to a flare; steady tank-battery or low-pressure volumes suit a combustor.
• Location.Near homes, roads, or sensitive sites, an enclosed combustor's hidden flame and provable efficiency usually wins.
• Compliance. If you need to document a specific combustion efficiency, an enclosed unit is far easier to prove than an open flame.

Whichever you run, it needs a burner management system that lights it reliably and proves the flame — here's how a BMS does that. We service both: flare service and combustor service, plus combustion design and burner sizing if you're speccing a new unit.