API RP 2216:2003(R2010) pdf download.Ignition Risk of Hydrocarbon Liquids and Vapors by Hot Surfaces in the Open Air
1.1 SCOPE
This recommended practice provides information concern- ing the potential for ignition of hydrocarbons that are exposed to hot surfaces in the open air. Hydrocarbon liquids, when heated sufficiently, can ignite without the application of a flame or spark. The ignition of hydrocarbons by hot surfaces may occur when oil is released under pressure and sprays on a hot surface or is spilled and lies on a hot surface for a period of time. Understanding the mechanism and dynamics of auto- ignition is an important step in preventing or controlling the ignition of hydrocarbons by hot surfaces in the open air. In addition to the information provided herein, appropriate industry standards and other information may assist users to understand the potential hazards of hydrocarbon auto-ignition (such as spontaneous combustion) not specifically covered by this publication and implement appropriate prevention and control measures.
1.2 APPLICABILITY
Hot surfaces, in areas where hydrocarbon liquids or vapors are present and may be released, are often presumed to be the sources of ignition should fires occur. However, it is generally recognized by the petroleum industry that hot surfaces, even at temperatures considerably above the auto-ignition temper- atures (AIT) of the hydrocarbons involved, are not always capable of igniting flammable vapor-in-air mixtures. This publication provides information applicable to the better understanding and controlling of hot surface ignition hazards.
1.3 NON-APPLICABILITY
This recommended practice does not cover every possible hazard or situation that may involve ignition of hydrocarbon liquids and vapors from hot surfaces. This publication does not apply to the ignition of hydrocarbons when certain condi- tions occur, such as spontaneous combustion (see 2.2). The mechanism for spontaneous combustion is entirely different from that required for ignition of hydrocarbon vapors from contact with hot surfaces in open air. This publication also does not apply to the ignition of hydrocarbon vapors when contacted by heated or glowing metal such as welding slag or by direct impact of super-hot exhaust fumes or gases. In addi- tion, this publication does not cover ignitions arising from hydrocarbon liquids trapped behind rust or oil soaked or satu- rated insulation or rust covering hot surfaces.