ASTM_F_1574_-_03a_2009.pdf

Designation:F157403a(Reapproved 2009)Standard Test Method forCompressive Strength of Gaskets at ElevatedTemperatures1This standard is issued under the fixed designation F1574;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 test method covers the determination of compres-sive strength characteristics(crush-extrusion resistance)ofgasket materials at elevated temperature.1.2 The values stated in SI units are to be regarded as thestandard.The values in parentheses are for information only.1.3 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2F104 Classification System for Nonmetallic Gasket Materi-alsF1315 Test Method for Density of a Sheet Gasket Material3.Summary of the Test Method3.1 Specimens cut from gasket material are subjected tovarious stresses perpendicular to the flat surface of the speci-mens for a specified time at 150C(302F).Dimensionalchanges to the thickness and in the plane of the specimen aredetermined while it is under stress and after the stress has beenremoved.A graphical display of percent deformation plottedagainst the applied stress will enable determination of acompressive yield stress point beyond which the material willno longer decrease in thickness without also extruding in theplanar dimensions.This condition is also revealed by physicalmeasurements of the change in size of the specimens in theplanar dimensions.Tests may be performed at various tempera-tures,as agreed upon between the producer and the user,todetermine the relationship between temperature and compres-sive behavior.4.Significance and Use4.1 The compressive strength or crush-extrusion resistanceof a gasket material is a major factor with regard to theselection of a given material for use in a particular sealingapplication.The significance of the test method is based,inpart,on the assumption that a material,once it has beencrushed or extruded,will no longer function as effectively as aseal.This assumption can only be used as a guide,however,since exact yield or failure points are difficult to define forgasket materials(which are usually viscoelastic in nature).Twoor more materials can be compared to determine differences intheir resistance to compressive stress.Asample of material canbe compared to an established standard or previously deter-mined characteristics on original lots of the same material,forquality assurance purposes.See 6.2 for discussion of specimenarea and geometry effects.5.Apparatus5.1 Testing Machine3,for applying a known value of com-pressive stresses to specimens.The machine should be capableof applying a stress of up to 520 MPa(75 400 psi)(toleranceof 65%),depending on the indent resistance of the steelplatens and the means of reading the applied load.5.2 Hardened Steel Platens,Two(Rockwell of C35 to 40 orequivalent),circular shape,larger than the specimen diameter.A suitable size is a diameter of approximately 100 mm(3.94in.).The surface finish shall be RMS 0.25 to 0.50 m(10 to 20m).Fig.1 shows a suitable arrangement of steel platens andtest specimen.5.3 Device for Applying Heat to Platens sufficient to achievea desired temperature at interface with gasket material speci-mens.An example of this device is also shown in Fig.1,wherea resistance heater surrounds the hardened platens.In somecases,the loading device itself may be heated,such as with a1This test method is under the jurisdiction of ASTM Committee F03 on Gasketsand is the direct responsibility of Subcommittee F03.20 on Mechanical TestMethods.Current edition approved Oct.1,2009.Published April 2010.Originallyapproved in 1995.Last previous edition approved in 2003 as F1574 03a.DOI:10.1520/F1574-03AR09.2For 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.3Examples of such equipment include Baldwin-Southwark,Instron,Tinius-Olsen,MTS,or any type of pressing device which has been properly calibrated toapply a known force.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 hot press.Any appropriate means is acceptable.The recom-mended elevated temperature is 150 6 5C(302 6 9F).Othertemperatures may be employed as desired,or as agreed uponbetween the producer and the user.5.4 Temperature Measuring Device for use at interface,suchas a thermocouple assembly and a means for recording thevoltage.