What is the typical flammable concentration range of natural gas in air?

What is the typical flammable concentration range of natural gas in air?

• A. 0-2%
• B. 2-4%
• C. 14-40%
• D. 4 - 14%

Answer: (D)

Natural gas ignites only when its concentration in air falls within a certain window — too lean and it won’t ignite, too rich and it won’t burn either. For methane, the main component of natural gas, this flammable range is about 5% to 15% by volume in air. So a concentration around 4% to 14% sits inside that window, where ignition is possible. That’s why this range is the best match: it captures the practical flammability limits. Concentrations well below are too lean to ignite, and concentrations well above are too rich to ignite.

Natural gas ignites only when its concentration in air falls within a certain window — too lean and it won’t ignite, too rich and it won’t burn either. For methane, the main component of natural gas, this flammable range is about 5% to 15% by volume in air. So a concentration around 4% to 14% sits inside that window, where ignition is possible. That’s why this range is the best match: it captures the practical flammability limits. Concentrations well below are too lean to ignite, and concentrations well above are too rich to ignite.