Ignition risks

As a guide, because of convection that occurs from hot surfaces, ignition by a hot surface in open air should not be assumed unless the surface temperature is at least 200°C above the published minimum autoignition temperature (American Petroleum Institute, Ignition Risk of Hot Sui faces, API PSD 2216, Washington, 1980). 

In view of the above adverse effects a safety factor should be applied where flammability is assessed using flash point. For pure liquids in containers the vapor should be considered potentially flammable if the liquid temperature is upward of at least 5°C below the reported flash point. For mixtures whose composition is less certain, such as petroleum mixtures, the safety factor should be about 15°C relative to the flash point [55]. Where combinations of adverse effects are identified the safety factors should be increased accordingly. A simple but very conservative approach is to assume that all liquids having a flash point <141°F may produce a flammable atmosphere under some ambient conditions, even where no mist or froth production is involved. A more practical approach is to assume that liquids handled in air at least 5-15°C below their closed cup flash points will not present ignition risks unless... 

It was not nndl the 1950s that detonation flame arresters made of crimped metal ribbon elements were developed and began to be used more freqnendy (Binks 1999). The major impetus for die use of crimped metal ribbon detonation flame arresters in the US was the enactment of clean air legislation (Clean Air Act of 1990) which inadvertently created a safety problem by requiring reductions in volatile organic compound (VOC) emissions. To do this, manifolded vent systems (vapor collection systems) were increasingly installed in many chemical process industry plants which captured VOC vapors and transported them to suitable recovery, recycle, or destruction systems. This emission control requirement has led to the introdnction of ignition risks, for example, from a flare or via spontaneous combustion of an activated carbon adsorber bed. Multiple... 

Selected aspects of safe practice in solids handling are covered below. For additional information, refer to the rules for plant safety prepared by the Expert Commission for Safety in the Swiss Chemical Industry (ESCIS, 1988). While making no mention of fluidization, this source provides many practical suggestions for the avoidance of electrostatic ignition risks in powder handling operations. 

In the production of wet process hardboards and serai-hardboards the press-dried boards are usually tempered or "cured" in hot air to increase their water resistance, dimensional stability, strenght and stiffness. A curing for 5 hours or more in hot air of 165°C is common. Higher curing temperatures reduce the period needed for each batch and thus increase the capacity of the heat treatment chamber, but they increase the auto-ignition risks. 

American Petroleum Institute (API), Publication 2216, Ignition Risk of Hydrocarbon Vapors bv Hot Surfaces in the Open Air. Second Edition, API, Washington, D.C., 1991. 

Nevertheless, as discussed in Section 3.7.3, where potentially flammable atmospheres exist, users must always consider the electrostatic ignition risks. 

Gibson, N., Effect of electrification in ball valves on ignition risk in liquid pipeline systems, J. Electrostatics 1, 339-350, 1975. 

Lessen ignition risks by selective wetting fuels present at the incision including gauze, sponges, and towel. 

Implement all general procedures established to minimize ignition risks. 

Specific procedures to minimize ignition risks in oropharyngeal surgery include gas scavenging and using... 

Water-containing hydraulic fluids have evolved since the late 1940s in response to the fire ignition risks of oil systems. The safety concerns of the steel, mining, and offshore users have played a 10 major part here. 

API Data Sheet 2216 Ignition Risk of Hot Surfaces in Open Air. 

American Petroleum Institute (API). RP 2216, Ignition risk of hydrocarbon liquids and vapors by hot surfaces in the open air. 3rd ed.Washington, DC API 2010 [Reaffirmed]. 

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