1、Designation: E2929 13Standard Practice forGuided Wave Testing of Above Ground Steel Piping withMagnetostrictive Transduction1This standard is issued under the fixed designation E2929; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、 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 provides a guide for the use of wavesgenerated using magnetostrictive transduction technolo
3、gy forguided wave testing (GWT) welded tubulars. Magnetostrictivematerials transduce or convert time varying magnetic fieldsinto mechanical energy. As a magnetostrictive material ismagnetized, it strains. Conversely, if an external force pro-duces a strain in a magnetostrictive material, the materia
4、lsmagnetic state will change. This bi-directional coupling be-tween the magnetic and mechanical states of a magnetostrictivematerial provides a transduction capability that can be used forboth actuation and sensing devices.1.2 GWT utilizes ultrasonic guided waves in the 10 toapproximately 250 kHz ra
5、nge, sent in the axial direction of thepipe, to non-destructively test pipes for discontinuities or otherfeatures by detecting changes in the cross-section or stiffness ofthe pipe, or both.1.3 GWT is a screening tool. The method does not providea direct measurement of wall thickness or the exact dim
6、ensionsof discontinuities. However, an estimate of the severity of thediscontinuity can be obtained.1.4 This practice is intended for use with tubular carbonsteel products having nominal pipe size (NPS) 2 to 48corresponding to 60.3 to 1219.2 mm (2.375 to 48 in.) outerdiameter, and wall thickness bet
7、ween 3.81 and 25.4 mm (0.15and 1 in.).1.5 This practice only applies to GWT of basic pipeconfiguration. This includes pipes that are straight, constructedof a single pipe size and schedules, fully accessible at the testlocation, jointed by girth welds, supported by simple contactsupports and free of
8、 internal, or external coatings, or both; thepipe may be insulated or painted.1.6 This practice provides a general practice for performingthe examination. The interpretation of the guided wave dataobtained is complex and training is required to properlyperform data interpretation.1.7 This practice d
9、oes not establish an acceptance criterion.Specific acceptance criteria shall be specified in the contractualagreement by the cognizant engineer.1.8 UnitsThe values stated in SI units are to be regardedas standard. No other units of measurement are included in thisstandard.1.9 This standard does not
10、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:
11、2E543 Specification for Agencies Performing NondestructiveTestingE1065 Guide for Evaluating Characteristics of UltrasonicSearch UnitsE1316 Terminology for Nondestructive ExaminationsE1324 Guide for Measuring Some Electronic Characteristicsof Ultrasonic Testing InstrumentsE2775 Practice for Guided Wa
12、ve Testing of Above GroundSteel Pipework Using Piezoelectric Effect TransductionIEEE/SI-10 American National Standard for Metric Practice2.2 Other Standards:3SNT-TC-1A Personnel Qualification and Certification inNon-Destructive Testing3. Terminology3.1 Definitions of terms specific to this standard
13、are pro-vided in this section. Some common terms such as defect maybe referenced to Terminology E1316.3.2 Definitions of Terms Specific to This Standard:1This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.10 o
14、nSpecialized NDT Methods.Current edition approved June 1, 2013. Published June 2013. DOI: 10.1520/E2929-132For 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 standa
15、rds Document Summary page onthe ASTM website.3Available fromAmerican Society for Nondestructive Testing (ASNT), P.O. Box28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http:/www.asnt.orgCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United Sta
16、tes13.2.1 circumferential extentthe length of a discontinuity inthe circumferential direction, usually given as a percentage ofthe pipe circumference.3.2.2 circumferential orientationthe circumferential posi-tion of a localized indication on the pipe, usually given as theclock position or degrees fr
17、om the top circumferential positionof the pipe.3.2.3 coherent noiseindications caused by real disconti-nuities causing a background noise, which exponentially de-cays with distance (see Terminology E1316).3.2.4 cross-sectional area change (CSC)the change in thecircumferential cross-section of pipe f
18、rom its nominal totalcross-section, usually given in percentage.3.2.5 dead zonethis is an area that can be up to1m(3ft)long on either side of the transducer ring that is not inspectedduring the testing. The area of the dead zone is a function of theexcitation frequency and the number of cycles trans
19、mitted. Thearea is inversely related to frequency and directly related to thenumber of cycles.3.2.6 estimated cross-sectional loss (ECL)this is some-times used instead of Cross-Sectional Area Change, where thefeature is related to a defect.3.2.7 flexural wavewave propagation mode that producesbendin
20、g motion in the pipe.3.2.8 guided wave (GW)stress waves travelling in a struc-ture bounded in the geometry and configuration of the struc-ture.3.2.9 guided wave testing (GWT)non-destructive testmethod that utilizes guided waves.3.2.10 incoherent noiserandom signals caused by electri-cal and ambient
21、radio frequency signal pollution, giving rise toa constant average noise floor. The terms “Ambient Noise” and“Random Noise” are also used.3.2.11 pipe featurepipe components including but notlimited to weld, support, flange, bend, and flaw (defect) causereflections of a guided wave due to a change in
22、 geometry.3.2.12 reflection amplitudethe amplitude of the reflectionsignal typically reported as CSC or reflection coefficient.3.2.13 reflection coeffcienta parameter that represents theamplitude of reflected signal from a pipe feature with respect tothe incident wave amplitude, usually expressed in
23、 percentageand called “% reflection.” Used in lieu of CSC to characterizethe severity of indications.3.2.14 reflector orientationthe circumferential position ofthe feature on the pipe. This is reported as the clock position ordegrees with regards to the orientation of the transductiondevice.3.2.15 s
24、hear wave couplantcouplant designed specificallyto effectively couple directly generated shear waves (waves notgenerated through refraction of longitudinal waves).3.2.16 signal to noise ratio (SNR)ratio of the amplitude ofany signal of interest to the amplitude of the average back-ground noise which
25、 includes both coherent and non-coherenttypes of noise.3.2.17 test locationlocation where the transduction deviceis placed on the pipe for inspection.3.2.18 time controlled gain (TCG)gain applied to thesignal as a function of time or distance from the initial pulseused to compensate wave attenuation
26、 in the pipeline. The TCGnormalizes the amplitude over the entire time scale displayed.For example, using TCG, a 5 % reflector near the probe has thesame amplitude as a 5 % reflector at the end of the time display.The TCG plot can be used in lieu of DAC curve plot.3.2.19 torsional wavewave propagati
27、on mode that pro-duces twisting motion in the pipe.3.2.20 transduction devicea device used to produce anddetect guided waves. It is commonly called “guided waveprobe.”3.2.21 wave modea particular form of propagating wavemotion generated into a pipe, such as flexural, torsional orlongitudinal.4. Summ
28、ary of Practice4.1 GWT evaluates the condition of metal pipes to primarilyestablish the severity classification of defects by applying GWover a typical test frequency range from 10 to approximately250 kHz which travels along the pipe. Reflections are gener-ated by the change in cross-sectional area
29、or local stiffness ofthe pipe, or both.4.2 The transduction device attached around the pipe gen-erates guided waves that travel in the pipe wall. The directionof wave propagation is controlled or can be in both directionssimultaneously. These guided waves can evaluate long lengthsof pipe and are esp
30、ecially useful when access to the pipe islimited.4.3 This examination locates areas of thickness reduction(s)and provides a severity classification as to the extent of thatdamage. The results are used to assess the condition of thepipe, to determine where damaged areas are located along thelength of
31、 the pipe, and their circumferential position on thepipe (when segmented transmitters or receivers, or both, areused). The information can be used to program and prioritizeadditional inspection work and repairs.4.4 Reflections produced by pipe features (such as circum-ferential welds, elbows, welded
32、 supports, vents, drainage,insulation lugs, and other welded attachments) and that are notassociated with areas containing possible defects are consid-ered as relevant signals and can be used for setting GW systemdefect detection sensitivity levels and time calibration.4.5 Other sources of reflectio
33、n may include changes insurface impedance of the pipe (such as pipe supports andclamps). These reflections are normally not relevant, butshould be analyzed and classified in an interpretation process.In the advanced applications which are not covered by thispractice, these changes may also include v
34、arious types ofexternal/internal coatings, entrance of the pipe to ground, orconcrete wall.4.6 Inspection of the pipe section immediately connecting tobranch connections, bends or flanges are considered advanceapplications which are not covered by this practice.E2929 1324.7 False indications are pro
35、duced by phenomena such asreverberations, incomplete control of wave propagationdirection, distortion at elbows, and others. These signals shouldbe analyzed and classified as false echoes in the interpretationprocess.5. Significance and Use5.1 The purpose of this practice is to outline a procedure f
36、orusing GWT to locate areas in metal pipes in which wall losshas occurred due to corrosion or erosion.5.2 GWT does not provide a direct measurement of wallthickness, but is sensitive to a combination of the CSC (orreflection coeffcient) and circumferential extent and axialextent of any metal loss. B
37、ased on this information, a classi-fication of the severity can be assigned.5.3 The GWT method provides a screening tool to quicklyidentify any discontinuity along the pipe. Where a possibledefect is found, a follow-up inspection of suspected areas withultrasonic testing or other NDT methods is norm
38、ally requiredto obtain detailed thickness information, nature, and extent ofdamage.5.4 GWT also provides some information on the axiallength of a discontinuity, provided that the axial length islonger than roughly a quarter of the wavelength.5.5 The identification and severity assessment of any pos-
39、sible defects is qualitative only. An interpretation process todifferentiate between relevant and non-relevant signals isnecessary.5.6 This practice only covers the application specified in thescope. The GWT method has the capability and can be used forapplications where the pipe is insulated, burie
40、d, in roadcrossings, and where access is limited.5.7 GWT shall be performed by qualified and certifiedpersonnel, as specified in the contract or purchase order.Qualifications shall include training specific to the use of theequipment employed, interpretation of the test results, andguided wave techn
41、ology.5.8 A documented program which includes training,examination, and experience for the GWT personnel certifica-tion shall be maintained by the supplying party.6. Basis of Application6.1 The following items are subject to contractual agree-ment between the parties using or referencing this practi
42、ce.6.2 Personnel QualificationsUnless otherwise specified inthe contractual agreement, personnel performing examinationsto this practice shall be qualified in accordance with one of thefollowing:6.2.1 Personnel performing examinations to this practiceshall be qualified in accordance with SNT-TC-1A a
43、nd certifiedby the employer or certifying agency, as applicable. Otherequivalent qualification documents may be used when speci-fied in the contract or purchase order. The applicable revisionshall be the latest unless otherwise specified in the contractualagreement between parties.6.2.2 Personnel qu
44、alification accredited by the GWT equip-ment manufacturers.6.3 This practice or standard used and its applicable revisionshall be identified in the contractual agreement between theusing parties.6.4 Qualifications of Non-destructive Testing AgenciesUnless otherwise specified in the contractual agree
45、ment, NDTagencies shall be qualified and evaluated as described inSpecification E543, and the applicable edition of SpecificationE543 shall be specified in the contractual agreement.6.5 Procedure and TechniquesThe procedures and tech-niques to be utilized shall be specified in the contractualagreeme
46、nt. It should include the scope of the inspection, that is,the overall NDT examination intended to identify and estimatethe size of any indications detected by the examination, orsimply locate and provide a relative severity classification.6.6 Surface PreparationThe pre-examination site prepa-ration
47、 criteria shall be in accordance with 8.3 unless otherwisespecified.6.7 Required Interval of ExaminationThe required inter-val or the system time in service of the examination shall bespecified in the contractual agreement.6.8 Extent of the ExaminationThe extent of the examina-tion shall be in accor
48、dance with 6.5 above unless otherwisespecified. The extent should include but is not limited to:6.8.1 The sizes and length(s) of pipes to be inspected.6.8.2 Limitations of the method in the areas of application.6.8.3 Drawings of pipe circuits, pipe nomenclature andidentification of examination locat
49、ions.6.8.4 Pipe access method(s).6.8.5 Safety requirements.6.9 Reporting CriteriaThe test results of the examinationshall be documented in accordance with the contractual agree-ment. This may include requirements for permanent records ofthe collected data and test reports. The report documentationshould include:6.9.1 Equipment inspector and test results reviewed by (ifapplicable).6.9.2 Date and time of the examination performed.6.9.3 Equipment used.6.9.4 Test procedure/specification used.6.9.5 Acceptance criteria.6.9.6 Inspection location.6.9.7 Identif
