ASTM_D_2155_-_18.pdf

Designation:D215518Standard Test Method forDetermination of Fire Resistance of Aircraft Hydraulic Fluidsby Autoignition Temperature1This standard is issued under the fixed designation D2155;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method is used for assessing the fire resistanceof hydraulic fluids used for aircraft applications by determina-tion of the autoignition temperature of the hydraulic fluid in airat one atmosphere pressure using hypodermic syringe injec-tion.1.2 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard is used to measure and describe theresponse of materials,products,or assemblies to heat andflame under controlled conditions,but does not by itselfincorporate all factors required for fire hazard or fire riskassessment of the materials,products,or assemblies underactual fire conditions.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Terminology2.1 Definitions:2.1.1 autoignition,nthe ignition of a material commonlyin air as the result of heat liberation due to the exothermicoxidation reaction in the absence of an external ignition sourcesuch as a spark or flame.2.1.2 autoignition temperature,nthe minimum tempera-ture at which autoignition occurs under the specified conditionsof the test.2.1.3 ignition,nthe initiation of combustion.2.1.4 ignition time lag,nthe time lapse between applica-tion of the heat to a material and its ignition;it is the time inseconds between the insertion of the sample into the flask andignition.3.Summary of Test Method3.1 A small metered sample of the fluid to be tested isinjected with a hypodermic syringe into a heated 200 mLErlenmeyer borosilicate glass flask containing air.The contentsof the flask are observed in a darkened room for 5 minfollowing injection of the sample or until autoignition occurs;autoignition is evidenced by the sudden appearance of a flameinside the flask.The lowest flask temperature at which autoi-gnition occurs for a series of prescribed sample volumes istaken to be the autoignition temperature of the fluid in air atone atmosphere pressure.4.Significance and Use4.1 Autoignition is dependent on the chemical and physicalproperties of the material and the method and apparatusemployed for its determination.The autoignition temperatureby a given method does not necessarily represent the minimumtemperature at which a given material will self-ignite in air.The volume of the vessel used is particularly important sincelower autoignition temperatures will be achieved in largervessels.Vessel material can also be an important factor.4.2 The temperatures determined by this test method arethose at which air oxidation leads to ignition.These tempera-tures can be expected to vary with the test pressure and oxygenconcentration.4.3 This test method is not designed for evaluating materialswhich are capable of exothermic decomposition.For suchmaterials,ignition is dependent upon the thermal and kineticproperties of the decomposition,the mass of the sample,andthe heat transfer characteristics of the system.4.4 This test method is not designed for evaluating for solidchemicals which melt and vaporize or which readily sublime atthe test temperature.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.N0 on Hydraulic Fluids.Current edition approved Dec.1,2018.Published February 2019.Originallyapproved in 1966.Last previous edition approved in 2012 as D2155 12.DOI:10.1520/D2155-18.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Comm