Le Chatelier Flammability Limits Calculator
Process safety engineering & explosion prevention: Determine Lower and Upper Flammability Limits ($LFL$ and $UFL$) of multi-component combustible gas blends.
Gas Mixture Composition (% by volume)
LFL: 5.0%, UFL: 15.0%
LFL: 3.0%, UFL: 12.4%
LFL: 2.1%, UFL: 9.5%
LFL: 4.0%, UFL: 75.0%
LFL: 12.5%, UFL: 74.2%
Non-combustible diluents
Le Chatelier's Law
For a mixture of combustible gases, the flammability limit is given by:
$$LFL_{\text{mix}} = \frac{100}{\sum_{i=1}^n \frac{y_i}{LFL_i}}$$
Where $y_i$ is the volume fraction of combustible gas $i$ on an inert-free combustible basis ($100\%$ total).
Flammability Envelope in Air
Lower Flammability Limit (LFL)
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Upper Flammability Limit (UFL)
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Safety Margins & Thresholds
NFPA Alarm Threshold (25% LFL)
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Warning beacon / ventilation trigger
NFPA Trip Threshold (60% LFL)
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Emergency shutdown / isolation
Gas Stream Characteristics
Combustible Fraction:
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Explosive Flammable Range:
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Composition Sum:
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