ASTM_F_1589_-_95.pdf

Designation:F 1589 95An American National StandardStandard Test Method forDetermination of the Critical Pressure for Rapid CrackPropagation in Plastic Pipe1This standard is issued under the fixed designation F 1589;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 minimum internal airpressure at which rapid crack propagation(RCP)can besustained along a section of plastic pipe.This is termed thecritical pressure.1.2 This technique achieves steady state RCP in a smallspecimen by restraining the decompression which normallyaccompanies fracture,and therefore indicates a lower criticalpressure than that measured on the same pipe using full-scaletests.This test method has been called“Small Scale SteadyState”or S4.1.3 This test method was developed for polyethylene pipe,and has been shown to correlate with the full-scale RCP testmethod.The user should determine if it is applicable to otherplastic piping methods.1.4 The values stated in inch-pound units are to be regardedas the standard.1.5 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:D 1600 Terminology for Abbreviated Terms Relating toPlastics2D 2122 Test Method for Determining Dimensions of Ther-moplastic Pipe and Fittings3F 412 Terminology Relating to Plastic Piping Systems32.2ISO Standard:ISO 3126 Plastic pipesMeasurement of dimensions43.Terminology3.1 DefinitionsDefinitions are in accordance with Termi-nology F 412,unless otherwise specified.3.1.1 axial pitchthe center to center distance of theretaining rings that surround the outside diameter.3.1.2 baffle pitchcenter to center distance of baffles.3.1.3 chisel-ended strikerthe knife-edged projectile(striker)that is used to initiate crack.3.1.4 gage lengthnominally 7D less initiation section andsealing sections;at least 4.5D.3.2 SymbolsThe following symbols are used in this testmethod for outside diameter controlled pressure pipe:3.2.1 aaxial crack length into the gage length of the pipetest piece.3.2.2 Dminimum outside diameter of pipe,which is theaverage outside diameter less the minus tolerance.3.2.3 pinternal pressure within the gage length of the pipetest piece.3.2.4 PcS4critical pressure for rapid crack propagation,measured using the S4 method.3.2.5 dminminimum inside diameter of pipe,calculated asfollows:dmin5 DF1 22.24SDRG3.3 Other abbreviations are in accordance with TerminologyD 1600.4.Significance and Use4.1 A specified length of pipe,subject to constant internalair pressure,is penetrated near one end by a chisel-endedstriker to result in a fast-running axial crack,under conditionswhere the crack initiation process itself disturbs the pipe aslittle as possible.4.2 Aseries of tests at various measured pressures is used toidentify the critical pressure,at which there is a sharp transitionfrom abrupt arrest of this initial crack to continued steadypropagation.The crack is said to propagate if the crack lengtha is greater than 4D.The critical pressure,PcS4,is themaximum arrest pressure below the lowest propagationpressure.Rapid decompression due to propagation of the crackis retarded by internal baffles and by an external cage whichrestricts flaring of the pipe at the edges of the fracture.TheRCP critical pressure becomes more significant for plastic pipeas the pipe size increases or the internal pressure increases,orboth.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 March 15,1995.Published May 1995.2Annual Book of ASTM Standards,Vol 08.01.3Annual Book of ASTM Standards,Vol 08.04.4Available from American National Standards Institute,11 W.42nd St.,13thFloor,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 ASTM5.Apparatus5.1 The apparatus should generally conform with Fig.1.5.2 The containment cage shall allow free expansion of thepipe during pressurization,but must restrict radial expansionduring fracture to within a maximum diameter of 1.1D at allpoints around the circumference.All pipe dimensionalmeasurements shall be made using Test Method D 2122 or ISO3126.5.3 The axial pitch of containment rings shall be less than0.4D,and their axial separation shall be(0.256 0.05)D,between the initiation impact point and the end of the gagelength.5.4 The internal gage length shall be greater than 4.5D.Atleast 70