Definition(s)
LFL
Lower flammable limit.
Source: API RP 14F, Design, Installation, and Maintenance of Electrical Systems for Fixed and Floating Offshore Petroleum Facilities for Unclassified and Class 1, Division 1 and Division 2 Locations, Fifth Edition, July 2008. Global Standards
Source: API RP 14G, Recommended Practice for Fire Prevention and Control on Fixed Open-type Offshore Production Platforms: Upstream Segment, Fourth Edition, April 2007. Global Standards
Source:API Standards 2217A, Guidelines for Safe Work in Inert Confined Spaces in the Petroleum and Petrochemical Industries, Fourth Edition, July 2009. Global Standards
LFL
The minimum concentration of a vapor in air (or other oxidant) below which propagation of flame does not occur on contact with an ignition source. The LFL is usually expressed as a volume percentage of the vapor in air. Sometimes called lower explosive limit (LEL). In popular terms, a mixture containing a percentage of flammable vapor below the LFL is too “lean” to burn.
Source:API Standards 2217A, Guidelines for Safe Work in Inert Confined Spaces in the Petroleum and Petrochemical Industries, Fourth Edition, July 2009. Global Standards
LFL
Volume fraction of flammable gas or vapour in air below, which an explosive gas atmosphere does not form, expressed as a percentage (see IEC 60079-20)
NOTE This is also known as lower explosive limit (LEL).
Source: IEC 60079-29-1, Explosive atmospheres – Part 29-1: Gas detectors – Performance requirements of detectors for flammable gases. Global Standards