ASTM_F_118_-_13.pdf

Designation:F11813Standard Definitions of Terms Relating toGaskets1This standard is issued under the fixed designation F118;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This standard is a compilation of terminology,relateddefinitions,and descriptions of terms used in the gasketindustry.Included terms are those used to define materials,testing technology,and testing results related to gaskets.2.Terminologyadhesionthe measurable attraction or bonding of a gasketmaterial to a surface after the application of temperature,orcompressive stress,or both.F607annulusa cut gasket shape consisting of two concentriccircles of known geometry.bindera component of certain gasket materials,which so-lidifies the structure,imparts uniform adhesion to surfaces,and has an impact on the pore structure and resiliency.blowout,gasketthe sudden release of internal pressure by agasket sealing a flange with a given stress applied.Theinternal pressure needed to create a blowout is also known asthe blowout pressure.F434classificationa means of specifying categories of gasketmaterials according to composition,method of manufacture,mechanical characteristics,and physical characteristics.F104combustiblescomponents of gasket material which are loston ignition at a given temperature.F495compressed thicknessthe measured thickness of a gasketmaterial with a known compressive stress pressibilityin compressibility/recovery testing of gasketmaterials,the difference between the specimen thicknessunder preload and thickness under total load,divided by thethickness under preload,expressed as a percent.F36,F806compressivestrength/crushextrusionresistancemaximum compressive stress before crush occurs at aspecified temperature without regard for leakage.F1574compressive yieldthe point which the slope of the relation-ship between applied stress and deformation of a gasketmaterial changes.F1574creepa transient stress-strain condition in which the strainincreases as the stress remains constant.(This condition isapproached in flat-face gasketing joints in which the boltundergoes a high elongation relative to any creep that mighttake place in the gasket.)F38creep relaxationa transient stress-strain condition in whichthe strain increases concurrently with the decay of stress.(This is the most common condition existing in flat-facegasketing assemblies in which the bolt exhibits a relativelylarge amount of elongation.)Strain is related to materialcreep under the flange and stress is related to boltstretch/elongation.F38cross-sectional areathe area of a gasket specimen defined asthe width times the thickness.crushmaximum load capability of a gasket material has beenexceeded by excessive external force,causing permanentdeformation of the material matrix.This permanent defor-mation is normally exhibited as splits in the gasket materialupon disassembly of the joint.deflectiongasket material deformation in the“thicknessdirection”caused by the application of stress.F1276deformationthe percentage by which a gasket material isdeformed under stress or after the application of stress.F1574densitythe mass per unit volume for a given gasket materialmeasured under defined conditions.F1315description/line call outan alphanumeric term used todefine the composition,method of manufacture,mechanicalproperties,and physical properties of a gasket material.F104,F868disintegrationthe process by which a gasket material breaksup into components or fragments after exposure to a givenfluid and/or environment.F148durabilitythe resistance to disintegration of a gasket mate-rial after exposure to a given fluid and/or environment.F1481These definitions are under the jurisdiction of ASTM Committee F03 onGaskets and are the direct responsibility of Subcommittee F03.94 on Terminology.Current edition approved July 1,2013.Published August 2013.Originallyapproved in 1970.Last previous edition approved in 2012 as F118 04(2012).DOI:10.1520/F0118-13.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 extrusionthe measurable amount of permanent movement ofa gasket material to unconstrained areas(that is,open flangeedges)when excessive external forces are applied to all orpart of the gasket matrix.flangethe members of a gasketed joint that compress thegasket.flange distortiondeviation of a contact surface from aperfect plane.flange misalignmentan off-set between gasket flanges thatcan induce additional external“per unit area”forces upon agasket due to less than design intent area under compression.flanged jointsee gasketed joint,which is a preferred term.flat faced jointa joint or flange with no raised contactsurface.flexibilitythe ratio of mandrel size a gasket material can bebent 180 degre