1、Designation: F118 13Standard 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. A number in parentheses indic
2、ates the year of last reapproval. A superscriptepsilon () 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 m
3、aterials,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 kn
4、own 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. The
5、internal 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 mater
6、ial 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
7、total load, divided by thethickness under preload, expressed as a percent. F36, F806compressive strength/crush extrusion resistancemaximum compressive stress before crush occurs at aspecified temperature without regard for leakage. F1574compressive yieldthe point which the slope of the relation-ship
8、 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 cree
9、p 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 elongat
10、ion.) 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, caus
11、ing 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 wh
12、ich 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, mechanicalprope
13、rties, 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 f
14、luid 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
15、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 States1extrusionthe measurable amount of permanent movement ofa gasket material to unconstrained areas (that is, open flangeedges) when excessive
16、 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” fo
17、rces 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 degrees around without cracking to
18、the thickness ofsaid gasket material. F147fluida gas or liquid used for immersion and sealabilitytesting of gasket materials. F37, F146gasketa material that may be clamped between faces andacts as a static or dynamic seal. Gaskets are cut, formed, ormolded into the desired configuration. They may co
19、nsist ofany of the following constructions:(a) One or more plies of a sheet material;(b) Composites of dissimilar materials; and(c) Materials applied as a bead or other form to one or bothmating faces prior to assembly.gasketed jointthe collective total of all members used toeffect a gasketed seal b
20、etween two or more separate items.leakthe passage of matter through interfacial openings orpassageways, or both, in or around the gasket.leak ratethe rate at which fluid escapes from a gasketedjoint.leakagethe amount of loss or escape of any media (fluid orgas) intended to be contained by the gasket
21、ed system.linear dimensional stabilitythe degree to which a gasketmaterial maintains its original size in the x-y plane afterexposure to specific conditions.maintenance factor, mthe factor that provides the addi-tional preload capability in the flange fasteners to maintainsealing pressure on a gaske
22、t after internal pressure is appliedto the joint.manometera device used to measure pressure in a closedsystem. It may be used to measure leakage of fluids throughgasketed joints.peak loadthe highest stress a gasket material can resistbefore tensile failure. F152platensrigid circular test plates dril
23、led with a hole for thecenter bolt, used to compress the test specimen underspecified load.recoveryin compressibility/recovery testing of gasketmaterials, the difference between the specimen recoveredthickness and thickness under total load, divided by thedifference between the thickness under prelo
24、ad and thicknessunder total load, expressed as a percent.relaxometerassembly used in creep relaxation tests whichconsists of two platens, special drilled and calibrated bolt,washer and nut. F38, F1276resiliencyin compressibility/recovery testing of gasketmaterials, the difference between the specime
25、n recoveredthickness and thickness under total load, divided by thethickness under total load, expressed as a percent.sealabilitythe measure of leak rate a gasket material has fora given gasket geometry, fluid with applied internal pressure,and applied flange pressure. Typically reported as a volume
26、or mass of fluid loss for a given time period and used asmeans of comparison. F37strainthe deformation of a gasket specimen under the actionof applied force or stress.stressThe force per unit area applied to a gasket material.stress relaxationa transient stress-strain condition in whichthe stress de
27、cays as the strain remains constant. (Thiscondition is encountered in grooved-face gasketing joints inwhich metal-to-metal contact occurs. This condition is alsoapproached in flat-face gasketing joints when the bolt ispractically infinitely rigid.)tensile strengththe maximum tensile stress applied d
28、uringstretching a specimen to rupture. F152tensile stressthe applied force per unit on original cross-sectional area of a specimen. F152torque bolta calibrated bolt (also called a drilled and pinnedbolt) made of a defined alloy that contains a pin mechanismwhich allows the user to measure bolt stret
29、ch. The bolt ispart of a relaxometer. F38, F1276yield factor (minimum design seating stress, y)the factorthat represents the pressure in megapascals (or pounds-forceper square inch) over the contact area of the gasket that isrequired to provide a sealed joint, with no internal pressurein the joint.F
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