Flash Point, Fire Point, and Auto-ignition Temperature

Describe the differences between flash point, fire point, and auto-ignition temperature. Which are more stable, combustible liquids or flammable liquids? Why?

Flash point refers to the temperature where in the vapors developed from fluid will catch fire in the ignition source presence. It refers to the least temperature in which a liquid fuel produces enough vapors to create an ignitable combination with air close to the surface. At this particular temperature, the vapors which is ignite will flash, but without continuous burn.  Although some applications may need a high flash point fluid, is normally ordinary to operate systems at temperature more than the fluid flash point. Fire point on the other hand refers to the temperature where in the fluid will maintain a fire in case ignited by external source of ignition. It is the temperature where in a liquid fuel will create vapors enough to maintain combustion in case ignited. This point is normally a few degrees past the flash point. The systems of heat transfer are usually run at a temperature higher than fire point fluid as the fluid is confined in the system, far separate from ignition source. Auto ignition is the least temperature where in a fluid will impulsively ignite with no external source of ignition that includes a spark or flame. One is not allowed to operate a system beyond its fluid auto ignition temperature. According to the provided variations, fluids are required to be utilized above their fire and flash point. However, they are not required to be utilized past their auto ignition temperatures (Ishida & Iwama, n.d.).

Flammable liquids contain flash points below 100oC, while combustion liquids contain their flash point above or at100oC. This means flammable liquids can be ignited at room temperature and thus they are more hazardous compared to combustible liquids. Thus combustible liquids can be regarded to be more stable. However, combustible liquids pose severe fire or/and explosion dangers when heated (Tkolb.net, n.d.).

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