ASTM_F_1474_-_98.pdf

Designation:F 1474 98An American National StandardStandard Test Method forSlow Crack Growth Resistance of Notched PolyethylenePlastic Pipe1This standard is issued under the fixed designation F 1474;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method determines the resistance to slow crackgrowth2,3of polyethylene pipe expressed in terms of time tofailure of the pipe with machined axial notches in a hydrostaticstress rupture test.1.2 The values stated in inch-pound units are to be regardedas the standard.1.3 This standard does not purport to address all of thesafety problems,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.NOTE1A similiar test method is described in ISO 13479.2.Referenced Documents2.1 ASTM Standards:D 1598 Test Method for Time-to-Failure of Plastic PipeUnder Constant Internal Pressure4D 1600 Terminology for Abbreviated Terms Relating toPlastics5D 2122 Method for Determining Dimensions of Thermo-plastic Pipe and Fittings4F 412 Terminology Relating to Plastic Piping Systems42.2ISO Standards:ISO 1167 Plastics pipes for the transport of fluidsDetermination of resistance to Internal Pressure6ISO 3126 Plastics pipesMeasurement of dimensions6ISO 13479 Polyolefin Pipes for the Conveyance of Fluids-Determination of Resistance to Crack PropagationTestMethod for Slow Crack Growth on Notched Pipes(NotchTest)63.Terminology3.1 GeneralDefinitions are in accordance with Terminolo-gies in F 412,unless otherwise specified.Abbreviations are inaccordance with Terminology D 1600.4.Significance and Use4.1 Pipe test samples with four external axial machinednotches are subjected to a constant pressure hydrostatic stressrupture test while immersed in a water tank at 80C(176F).The time to failure is recorded.The test is applicable to pipe ofwall thickness 0.2 in.(5 mm).5.Apparatus5.1 Pipe Test Equipment,as described in ISO 1167 or TestMethod D 1598.5.2 Milling Machine,which has a horizontal mandrel rigidlyfixed to the bed to enable the pipe to be securely clamped togive a straight specimen.The mandrel shall support the pipebore beneath and along the full length of the notch to bemachined.The milling cutter mounted on a horizontal arborshall be a 60 included angle V cutter,0.5 in.(12.5 mm)widehaving a cutting rate of 0.00040 6 0.00008 in.(0.010+0.002mm)/rev/tooth.NOTE2For example a cutter with 20 teeth rotating at 700 rpm,traversed along at a speed of 6 in./min(150 mm/min)has a cutting rate asfollows:6/20 3 700!5 0.00042 in./rev!/tooth150/20 3 700!5 0.011 mm/rev!/tooth6.Procedure6.1 Specimen PreparationTake a pipe sample with aminimum free length between the end caps of 3 3 pipe outsidediameter 60.2 in.(5 mm).6.1.1 Pipe Measurement:6.1.1.1 The minimum pipe wall thickness shall be locatedand marked for machining the initial notch.6.1.1.2 The positions shall be marked for machining threeadditional notches equally spaced around the pipe circumfer-ence at the same axial position as the initial notch(see Fig.1).6.1.1.3 The average wall thickness shall be recorded frommeasurements taken at either end of the specimen in line withthe positions for each of the four notches.1This test method is under the jurisdiction of ASTM Committee F-17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.40 on TestMethods.Current edition approved December 10,1998.Published March 1999.Originallyoublished as F 1474-93.Last previous edition F 1474-93.2Denning,J.A.,Eleventh Plastic Fuel Gas Pipe Symposium,San Francisco,CA,1989,p.249.3Dickinson,A.and Ewing,L.,International Gas Research Conference,Toronto,Canada,Vol 1,1986,p.52.4Annual Book of ASTM Standards,Vol 08.04.5Annual Book of ASTM Standards,Vol 08.01.6Available from American National Standards Institute,11 West 42nd Street,13th Floor,New York,NY 10036.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTM6.1.2 Machining Notches:6.1.2.1 Machine a notch with a ligament thickness between0.78 and 0.82 times the measured minimum wall thickness ofthe specimen,as shown in Fig.2.NOTE3To achieve a remaining ligament within the required tolerancerange,it is advisable to aim for a remaining ligament at the top of thetolerance range.This is because the pipe wall can move due to release ofresidual stresses,resulting in a deeper than anticipated notch.6.1.2.2 The length of the notch,at full depth,shall be equalto the pipe outside diameter,60.04 in.(1 mm).6.1.2.3 The three other notches at the positions indicatedshall be machined to give a ligament thickness id