ASTM_F_2836_-_18.pdf

Designation:F283618Standard Practice forGasket Constants for Bolted Joint Design1This standard is issued under the fixed designation F2836;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.Scope1.1 This practice determines room temperature gasket tight-ness design constants for pressurized bolted flanged connec-tions such as those designed in accordance with the ASMEBoiler and Pressure Vessel Code.1.2 This practice applies mainly to all types of circulargasket products and facings typically used in process or powerplant pressure vessels,heat exchangers,and piping includingsolid metal,jacketed,spiral wound,and sheet-type gaskets.Asan optional extension of this practice,the maximum assemblystress for those gaskets may also be determined by thisprocedure.1.3 UnitsThe values stated in SI units are to be regardedas the standard,but other units may be included.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.Referenced Documents2.1 ASME Standards:2ASME B16.5 Steel Pipe Flanges and Flanged FittingsASME B16.20 Metallic Gaskets for Pipe FlangesRing-Joint,Spiral-Wound,and JacketedASME B16.21 Nonmetallic Flat Gaskets for Pipe FlangesASME Boiler and Pressure Vessel Code Section VIII Divi-sion 1,Appendix 23.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 ASME Class 150,nrefers to the dimensions andpressure rating of Class 150 of standard flanges in ASMEStandard B16.5.3.1.2 flange rotation,nrotation of the flange face surfacesso that the gasket outside diameter(OD)is compressed morethan the gasket inside diameter(ID)when the bolts aretightened to compress the gasket.3.1.3 gasket constants,nif a log-log plot of gasket stressversus tightness(Sg-Tp graph)is made and an analysis of thedata is performed in accord with this practice,then(see Fig.1):(1)The value,Gb,is the stress intercept(at Tp=1)associated with a regression of the Part A tightness data.(2)The value,a,is the slope associated with the PartAdataand combined values of Gb and a describe the seating orloading characteristic of a gasket and give an indication of thegasket capacity to develop tightness upon initial seating.(3)The value,Gs,is the stress intercept(at Tp=1)associated with Part B tightness data and values of Gs representthe gasket potential to maintain tightness after pressurizationand during operation and indicate the gaskets sensitivity tounloading excursions or susceptibility to crushing.(4)The combined effect of constants Gb and a is bestrepresented by the value of STp=Gb Tpacalculated fortypical values of Tp such as 100,1000,or 10 000 where STptells us what the minimum gasket stress shall be to maintain aspecified level of minimum tightness.(5)The value,Gs,is an independent constant that repre-sents operation and it characterizes the gasket tightness sensi-tivity to operating bolt load reductions that occur duringpressurization or gasket creep or thermal disturbances.3.1.4 gasket contact area,Ag,ninitial(nominal)area ofthe gasket that is considered to be loaded by the flangesurfaces.3.1.5 gasket stress,Sg,ngasket stress is the ratio of theapplied load by the fixture over the gasket contact area,Ag.3.1.6 gasket types,nfor this practice,it is convenient todifferentiate gasket styles as:(1)Sheet gasket materials typically from 0.5 to 5 mm thickcommonly in use and in which circular gasket samples are cut,1This practice is under the jurisdiction ofASTM Committee F03 on Gaskets andis the direct responsibility of Subcommittee F03.20 on Mechanical Test Methods.Current edition approved Aug.1,2018.Published November 2018.DOI:10.1520/F2836-18.2Available from American Society of Mechanical Engineers(ASME),ASMEInternational Headquarters,Two Park Ave.,New York,NY 10016-5990,http:/www.asme.org.Copyright 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)Committee.1 such as compressed or beater-added fib