LFL – Definition and Pronunciation
What is LFL?
LFL stands for Lower Flammable Limit, also known as Lower Explosive Limit (LEL). It denotes the minimum concentration of a combustible gas or vapor in air below which combustion cannot occur due to insufficient fuel. LFL is critical in assessing fire and explosion hazards in industrial environments.
Examples of LFL
At the flammable concentration boundary, typically close to the Lower Flammable Limit (LFL) of the vapour air mixture, the gas cloud can ignite and, if unobstructed, burn back to the source pool as a «flash-fire».
From Safety Liquefied Gas of Marine Transportation“Safety Transportation of LNG-LPG and Possible Risks”.
An issue with some gas detectors is that they automatically switch from percent volume to percent lower flammable limit (LFL) at low concentrations. Be sure you know what your meter is reading when you use it!
Aeration will usually continue until the oxygen content of the tank atmosphere is at 20,9 % by volume and hydrocarbon levels are less than 1 % of the LFL.
From Features of cargo delivery LNG/LPG carriers“Gas Transportation Operations for LNG and LPG Carriers”.