1、Designation: E2929 18Standard 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 for guid
3、ed wavetesting (GWT) welded tubulars. Magnetostrictive materialstransduce or convert time varying magnetic fields into me-chanical energy. As a magnetostrictive material is magnetized,it strains. Conversely, if an external force produces a strain ina magnetostrictive material, the materials magnetic
4、 state willchange. This bi-directional coupling between the magnetic andmechanical states of a magnetostrictive material provides atransduction capability that can be used for both actuation andsensing devices.1.2 GWT utilizes ultrasonic guided waves in the 10 toapproximately 250 kHz range, sent in
5、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 dimensionsof dis
6、continuities. 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 between 3.81 and
7、 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 internal, or
8、 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 does not estab
9、lish 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. The values given in parentheses are mathematicalconversions to SI units that are provided for infor
10、mation onlyand are not considered standard.1.9 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, health, and environmental practices and deter-mine the applicabi
11、lity of regulatory limitations prior to use.1.10 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the
12、World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2E543 Specification for Agencies Performing NondestructiveTestingE1316 Terminology for Nondestructive ExaminationsIEEE/SI-10 American National Standard for Metric Practice2.2 Other Standards
13、:3SNT-TC-1A Personnel Qualification and Certification inNon-Destructive Testing3. Terminology3.1 Definitions of terms specific to this standard are pro-vided in this section. Some common terms such as defect maybe referenced to Terminology E1316.1This practice is under the jurisdiction of ASTM Commi
14、ttee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.10 onSpecialized NDT Methods.Current edition approved June 1, 2018. Published June 2018. Originallyapproved in 2013. Last previous edition approved in 2013 as E292913. DOI:10.1520/E2929-18.2For referenced ASTM s
15、tandards, 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.3Available fromAmerican Society for Nondestructive Testing (ASNT), P.O. Box28518, 1
16、711 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization establi
17、shed in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.2 Definitions of Terms Specific to This Standard:3.2.1 circumferential extentthe length of a discontinuit
18、y 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 from the top circumferential positionof the pipe.3.2.3 coheren
19、t 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 from its nominal totalcross-section, usually given in percent
20、age.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 transmitted. Thearea is inversely related to frequency and direct
21、ly 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 producesbending motion in the pipe.3.2.8 guided wave (GW)stress waves trav
22、elling 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 radio frequency signal pollution, giving rise toa constant a
23、verage 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 geometry.3.2.12 reflection amplitudethe amplitude of the re
24、flectionsignal 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 percentageand called “% reflection.” Used in lieu of CSC to
25、 characterizethe severity of indications.3.2.14 shear wave couplantcouplant designed specificallyto effectively couple directly generated shear waves (waves notgenerated through refraction of longitudinal waves).3.2.15 signal to noise ratio (SNR)ratio of the amplitude ofany signal of interest to the
26、 amplitude of the average back-ground noise which includes both coherent and non-coherenttypes of noise.3.2.16 test locationlocation where the transduction deviceis placed on the pipe for inspection.3.2.17 time controlled gain (TCG)gain applied to thesignal as a function of time or distance from the
27、 initial pulseused to compensate wave attenuation 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 D
28、AC curve plot.3.2.18 torsional wavewave propagation mode that pro-duces twisting motion in the pipe.3.2.19 transduction devicea device used to produce anddetect guided waves. It is commonly called “guided waveprobe.”3.2.20 wave modea particular form of propagating wavemotion generated into a pipe, s
29、uch as flexural, torsional orlongitudinal.4. Summary 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
30、gener-ated by the change in cross-sectional area 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 w
31、aves can evaluate long lengthsof pipe and are especially 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 w
32、here damaged areas are located along thelength of 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 feature
33、s (such as circum-ferential welds, elbows, welded 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 an
34、d time calibration.4.5 Other sources of reflection 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
35、by thispractice, these changes may also include various 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 thi
36、s practice.4.7 False indications are produced by phenomena such asreverberations, incomplete control of wave propagationE2929 182direction, distortion at elbows, and others. These signals shouldbe analyzed and classified as false echoes in the interpretationprocess.5. Significance and Use5.1 The pur
37、pose of this practice is to outline a procedure forusing 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 circumfere
38、ntial extent and axialextent of any metal loss. Based 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 wi
39、thultrasonic testing or other NDT methods is normally 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 i
40、dentification and severity assessment of any pos-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 f
41、orapplications where the pipe is insulated, buried, 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, interpr
42、etation of the test results, andguided wave technology.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 bet
43、ween the parties using or referencing this practice.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 practice
44、shall be qualified in accordance with SNT-TC-1A and 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 contra
45、ctualagreement between parties.6.2.2 Personnel qualification 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 AgenciesUn
46、less otherwise specified in the contractual agreement, 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 util
47、ized shall be specified in the contractualagreement. 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
48、 PreparationThe pre-examination site prepa-ration 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 Examinatio
49、nThe extent of the examina-tion shall be in accordance 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 locations.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 requireme
