Example 7-13 Calculation of LEL for Flammable Mixture

Assume mixture analysis (combustible with air) Methane, 3.0%, LEL = 5.3% 

For each component v, combustible only on air-free basis. Methane % (100) = 37.5% 

The UEL for a composite is determined in the same manner, using the respective component UEL values. For the overall mixture, the above can be used to calculate the composition. Also see Ref [52]. 

Extreme care must be exercised in designing potentially flammable systems to use reliable flammability limits data and to recognize the effects of pressure/temperature on the data and its implications to the safety of the system in question. Unless otherwise indicated, most published data is at atmospheric pressure and ambient temperature and should be corrected for other conditions. 

If hot water and water vapor at 175°F are used to flush mixture A from the tank, the mixture composition can only shift along AC to E. Mixtures between A and E are flushed from the tank, mixed with air to give a mixture between parts AE and B. After examining several other 

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