1、Designation:F314915Standard Practice forDetermining the Maintenance Factor(m)and Yield Factor(y)Loading Constants Applicable to Gasket Materials andDesigns1This standard is issued under the fixed designation F3149;the number immediately following the designation indicates the year oforiginal adoptio
2、n 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 will establish criteria for determiningloading constants that are re
3、ferenced in the American Societyof Mechanical Engineers(ASME)pressure vessel design(Boiler and Pressure Vessel Code,Section VIII,Divs.1 and 2).These constants are specific to this design criterion formetallic,semi-metallic,and nonmetallic gaskets.1.2 UnitsThe values stated in inch-pound units are to
4、 beregarded as the standard.The values given in parentheses aremathematical conversions to SI units that are provided forinformation only and are not considered standard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of
5、the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D2000 Classification System for Rubber Products in Auto-motive ApplicationsF104 Classification System for
6、Nonmetallic Gasket Materi-alsF868 Classification for Laminated Composite Gasket Mate-rials2.2 ASME Standards:3B16.5 Pipe Flanges and Flanged Fittings:NPS 1/2 throughNPS 24 Metric/Inch Standard Boiler and Pressure VesselCode Section VIII,Divs.1 and 2PCC-1 Guidelines for Pressure Boundary Bolted Flang
7、eJoint Assembly2.3 DIN Standard:DIN 3535 Gaskets for Gas Supply42.4 FSA Standard:FSA G 605:11 Standard Test Method for Determining(m)and(y)Loading Constants Applicable to Gasket Materialsand Designs53.Terminology3.1 Definitions:3.1.1 gasket contact area,A1,ngasket area in contact withthe flange surf
8、aces and under load.3.1.1.1 DiscussionThe gasket contact area described inthis practice can deviate from the effective area described in theASME pressure vessel design.3.1.2 leak rate,nvolumetric leak rate per inch gasketoutside diameter.3.1.3 maintenance factor,m,nfactor that is required tocalculat
9、e the additional flange fastener preload needed tomaintain a seal after internal pressure is applied to a joint.3.1.4 surface stress,nstress applied to the gasket contactarea and equal to the applied load divided by gasket contactarea.3.1.5 yield factor,y,nfactor that provides the gasketminimum desi
10、gn seating stress required to seal a joint uponassembly.3.1.5.1 DiscussionThisassumesnopressureand,therefore,a lack of hydrostatic end load effect on the assembly.Reported in psi.4.Significance and Use4.1 The gasket factors are a function of leak rate;therefore,this practice generates curves.Constan
11、ts for use in the ASMEBoiler and Pressure Vessel Code,Section VIII,Appendix 21This practice is under the jurisdiction ofASTM Committee F03 on Gaskets andis the direct responsibility of Subcommittee F03.40 on Chemical Test Methods.Current edition approved June 1,2015.Published August 2015.DOI:10.1520
12、/F3149-15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from American Society of Mechanical Engineers
13、(ASME),ASMEInternational Headquarters,Two Park Ave.,New York,NY 10016-5990,http:/www.asme.org.4Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.5Available from the Fluid Sealing Association,994 Old Eagle School Rd.,#1019,Wayne,PA
14、 19087-1866.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 code calculations are selected from these data.Specific m andy values can be selected based on a maximum desired leak rateor derived from these data as described in this procedur
15、e.Thispractice addresses the influence of leak rate and gasketthickness on a gaskets ability to provide a seal initially and inoperation.This practice is performed at room temperature;therefore,this practice does not account for all conditions,suchas high temperature or thermal cycling or both,that
16、boltedflange connections may be subject to in field application.4.2 This practice determines two general characteristics thatare specific to the ASME design criteria.Caution should beexercised when comparing yield and maintenance factorsbetween gasket materials,and it is recommended that the mand y curves be compared.Selecting a gasket material for usein an application should not be based exclusively on these twogeneral characteristics.Gasket material selection for a givenapplication should cons
