What does LFL stand for in flammability diagrams?

What does LFL stand for in flammability diagrams?

• A. Lower Flammable Limit
• B. Upper Flammable Limit
• C. Limiting Oxygen Concentration
• D. Flammability Zone

Answer: (A)

In flammability diagrams, there is a lean side and a rich side where flame can occur. The lower boundary is the minimum fuel concentration in air that can sustain a flame—that’s the Lower Flammable Limit. Below this level, the mixture is too lean to ignite even with a spark. Keeping within the range between the lower and upper limits means the mixture has just the right amount of fuel to burn if there’s an ignition source. The upper boundary, the upper limit, marks where the mixture becomes too rich to ignite. So the term described by LFL is the Lower Flammable Limit.

In flammability diagrams, there is a lean side and a rich side where flame can occur. The lower boundary is the minimum fuel concentration in air that can sustain a flame—that’s the Lower Flammable Limit. Below this level, the mixture is too lean to ignite even with a spark. Keeping within the range between the lower and upper limits means the mixture has just the right amount of fuel to burn if there’s an ignition source. The upper boundary, the upper limit, marks where the mixture becomes too rich to ignite. So the term described by LFL is the Lower Flammable Limit.