A flame arrester (also spelled arrestor), deflagration arrester, or flame trap are safety devices fitted to openings of enclosures or to pipe work, and are intended to allow flow but prevent flame transmission fuel combustion by extinguishing the flame. Usage and applications The uses of a flame arrester include: Stopping the spread of an open fire Limiting the spread of an already occurred explosion Preventing potentially explosive mixtures from igniting Confining fire within a controlled location Stopping the propagation of a flame traveling at subsonic velocities Some common objects that have flame arresters are: Fuel storage tank vents Fuel gas pipelines Safety storage cabinets for paint, aerosol cans, and other flammable mixtures The exhaust system of internal combustion engines The air intake of marine inboard engines Davy lamps in coal mining Overproof rum and other flammable liquors. Portable plastic gasoline containers Principles Flame arresters are safety devices fitted to openings of enclosures or to pipe work, and are intended to allow flow but prevent flame transmission. A flame arrester functions by absorbing the heat from a flame front thus dropping the burning gas/air mixture below its auto-ignition temperature; consequently, the flame cannot survive. The heat is absorbed through channels (passages) designed into an element. These channels are chosen and measured as the MESG (maximum experimental safe gap) of the gas for a particular installation. These passages can be regular, like crimped metal ribbon or wire mesh or a sheet metal plate with punched holes, or irregular, such as those in random packing. The required size of the channels needed to stop the flame front can vary significantly, depending on the flammability of the fuel mixture. The large openings on a chain link fence are capable of slowing the spread of a small, slow-burning grass fire, but fast-burning grass fires will penetrate the fence unless the holes are very small. In a coal mine containing highly explosive coal dust or methane, the wire mesh of a Davy lamp must be very tightly spaced. For flame arresters used as a safety device, the mesh must be protected from damage due to being dropped or struck by another object, and the mesh must be capable of rigidly retaining its shape during the propagation of a flame front. Any shifting of the individual wires that make up the mesh can create an opening large enough to allow the flame to penetrate and spread beyond