1、Designation:F 1248 96(Reapproved 2002)e1An American National StandardStandard Test Method forDetermination of Environmental Stress Crack Resistance(ESCR)of Polyethylene Pipe1This standard is issued under the fixed designation F 1248;the number immediately following the designation indicates the year
2、 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(e)indicates an editorial change since the last revision or reapproval.e1NOTESection 3.2.2 and Tables 1-3 were editorially revised in November 2
3、002.1.Scope1.1 This test method covers the determination of a polyeth-ylene pipe specimens resistance to stress cracking whensubjected to compression deformation in the presence of asurface active agent at elevated temperature.1.2 The values stated in inch-pound units are to be regardedas the standa
4、rd.The values given in parentheses mathematicalconversions to SI units,which are provided for informationonly 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 the user of this standard to
5、 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 1600 Terminology for Abbreviated Terms Relating toPlastics2D 1693 Test Method for Environmental Stress Cracking ofEthylene Plastics3F
6、 412 Terminology Relating to Plastic Piping Systems43.Terminology3.1 DefinitionsDefinitions of terms are in accordance withTerminology F 412 and abbreviations are in accordance withTerminology D 1600,unless otherwise indicated.3.2 Definitions of Terms Specific to This Standard:3.2.1 environmental st
7、ress crack resistance(ESCR)anumber in units of hours-to-failure indicating the resistance ofPE pipe to cracking at stresses below the short-term mechani-cal stress values of the pipe while immersed in a surface-activeliquid at elevated temperature.3.2.2 failure,na crack in the surface of the pipe sp
8、ecimen,visible with the unaided eye.3.2.2.1 DiscussionExtension of the controlled notch is nota failure.Appearance of more than one crack in a specimenshall be classified as a single failure.4.Summary of Test Method4.1 A ring specimen of the polyethylene pipe,having acontrolled imperfection at one l
9、ocation,is exposed at anelevated temperature to the action of a surface active agentwhile compressed to deformation between parallel plates.Theelapsed time in hours to observation of a stress crack failure inthe specimen is recorded.5.Significance and Use5.1 This test method may be used to determine
10、 the environ-mental stress-crack resistance properties of a polyethylene pipespecimen while under high stress in the presence of thesurface-active agent,and at an elevated temperature.6.Apparatus6.1 Specimen HolderThe test-specimen holder shall con-sist of two parallel plates having a width at least
11、 1.2 times thenominal outside diameter of the pipe.Fig.1 shows suggesteddimensions for a holder for 114-in.pipe.Construction shall beof corrosion-resistant metal such as Type 304 or 316 stainlesssteel.The plates shall have a series of appropriately spacedholes through which bolts or threaded rod can
12、 be inserted toeffect compression of the test specimen by the use of nuts.It isrequired that spacers having a thickness equal to the distancerequired for compression be used to minimize the time to effectcompression of the test specimen to ensure consistent anduniform compression and to prevent over
13、compression.Theplates shall remain parallel throughout the testing period.6.2 Notching JigThe blade used shall be a single-edgestainless blade5(Table 1).The blade shall be replaced after ithas been used to produce 20 notches.Additionally,the blade1This test method is under the jurisdiction of ASTM C
14、ommittee F17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.40 on TestMethods.Current edition approved March 10,1996.Published May 1996.Originallypublished as F 1248 89.Last previous edition F 1248 96.2Annual Book of ASTM Standards,Vol 08.01.3Annual Book of ASTM Standa
15、rds,Vol 08.03.4Annual Book of ASTM Standards,Vol 08.04.5A blade made by the American Safety Razor Co.,Industrial Products Division,Razor Blade Lane,Verona,VA24482,or equivalent,has been found satisfactory forthis purpose.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohock
16、en,PA 19428-2959,United States.shall be inspected before each use employing a 43 magnifyingglass,and shall be replaced whenever there is question of itshaving become dull or damaged.The required blade holderdesign and dimensions are shown in Fig.2 and Fig.3.6.3 Constant-Temperature BathA covered container filledwith the test reagent and maintained at 122 6 3.6F(50 62C).Add distilled water as necessary to maintain the specifiedconcentration of the test reagent in the bath.The bath and othercompon
