1、Designation: E2906/E2906M 18Standard Practice forAcoustic Pulse Reflectometry Examination of Tube Bundles1This standard is issued under the fixed designation E2906/E2906M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, the year of
2、 last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes use of Acoustic Pulse Reflecto-metry (APR) technology for examination of the internalsurface
3、of typical tube bundles found in heat exchangers,boilers, tubular air heaters and reactors, during shutdownperiods.1.2 The purpose of APR examination is to detect, locate andidentify flaws such as through-wall holes, ID wall loss due topitting and/or erosion as well as full or partial tube blockages
4、.APR may not be effective in detecting cracks with tightboundaries.1.3 APR technology utilizes generation of sound wavesthrough the air in the examined tube, then detecting reflectionscreated by discontinuities and/or blockages. Analysis of theinitial phase (positive or negative) and the shape of th
5、ereflected acoustic wave are used to identify the type of flawcausing the reflection.1.4 When proper methods of signal and data analysis aredeveloped, APR technology can be applied for sizing offlaw/blockage indications.1.5 The values stated in either SI units or inch-pound unitsare to be regarded s
6、eparately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standards.1.6 This standard does not purport to address all of thesafety con
7、cerns, 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 applicability of regulatory limitations prior to use.1.7 This international standard was developed in accor-dance with
8、 internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:
9、2E543 Specification for Agencies Performing NondestructiveTestingE1316 Terminology for Nondestructive Examinations2.2 Other Documents:SNT-TC-1A Recommended Practice for NondestructiveTesting Personnel Qualification and Certification3ANSI/ASNT CP-189 ASNT Standard for Qualification andCertification o
10、f Nondestructive Testing Personnel3NAS-410 Certification and Qualification of NondestructiveTest Personnel4ISO 9712 Non-Destructive Testing Qualification and Cer-tification of NDT Personnel.3. Terminology3.1 DefinitionsSee Terminology E1316 for general termi-nology applicable to this practice.3.2 De
11、finitions of Terms Specific to This Standard:3.2.1 acoustic pulse reflectometrya technology fordetecting, locating and analyzing sound reflections caused bydiscontinuities and abrupt changes on the internal surface oftubes and pipes as a response to an induced acoustic signalwithin the examined stru
12、cture.3.2.2 reference signala measured signal from a typicaltube in the examined bundle without flaws or blockages.Reflections in the reference signal indicate structural featuresof the tube, probe or adaptor.3.2.3 signal-to-noise ratio (SNR)the ratio of the signalsRoot Mean Square (RMS) to RMS of t
13、he noise signal.3.2.4 output gainthe gain of the sound-source amplifier.1This test method is under the jurisdiction of ASTM Committee E07 onNondestructive Testing and is the direct responsibility of Subcommittee E07.10 onSpecialized NDT Methods.Current edition approved June 1, 2018. Published June 2
14、018. Originallyapproved in 2013. Last previous edition approved in 2013 as E2906/E2906M13.DOI: 10.1520/E2906_E2906M-18.2For 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
15、to the standards 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.org.4Available from Aerospace Industries Association of America, Inc. (AIA), 1000Wilson Blvd., Suite
16、 1700,Arlington, VA22209-3928, http:/www.aia-aerospace.org.Copyright 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 establishe
17、d 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.14. Summary of Practice4.1 This practice describes the use of APR technology todetect, locate and identify flaw
18、s and blockages in tube bundles.4.2 The practice describes typical APR apparatus and pro-vides guidelines for:4.2.1 APR system setup and performance verification.4.2.2 APR examination and evaluation of examination re-sults including signal analysis, indication detection, location,identification and
19、sizing.4.2.3 Preparation of examination report.5. Significance and Use5.1 APR technology is used for detection, location andidentification of internal diameter (ID) flaws-indications andblockages in tube bundles.5.2 Reliable and accurate examination of tube bundles is ofgreat importance in different
20、 industries. On-time detection offlaws reduces a risk of catastrophic failure and minimizesunplanned shutdowns of plant equipment. Fast examinationcapability is of great importance due to reduction of mainte-nance time.5.3 APR examinations are performed for quality control ofnewly manufactured tube
21、bundles as well as for in-serviceinspection.5.4 Performing an APR examination requires access to anopen end of each tube to be examined.5.5 Flaws that can be readily detected and identified includebut are not limited to through-wall holes, ID pitting, erosion,blockages, bulging due to creep and plas
22、tic deformation due tobending.5.6 APR can be applied to tube bundles made of metal,graphite, plastic or other solid materials with straight andcurved sections. The APR technology has been found effectiveon tubes with diameters between 12.7 mm 12 in. to 101.6 mm4 in. and lengths up to 18 metres 60 fe
23、et.5.7 Closed cracks on ID surface, without significant geo-metrical alternation on ID surface, may not be detected byAPR.5.8 APR technology can be used for flaw sizing whenspecial signal and data analysis methods are developed andapplied.5.9 In addition to detection of flaws and blockages, APRtechn
24、ology can be applied for assessing tube ID surfacecleanliness, providing valuable information for equipmentmaintenance and improving its performance.5.10 Other nondestructive test methods may be used toverify and evaluate the significance of APR indications, theirexact position, depth, dimension and
25、 orientation. These includeremote visual inspection, eddy current and ultrasonic testing.5.11 Procedures for using other NDT methods are beyondthe scope of this practice.5.12 Acceptable flaw size can be calculated using methodsof fracture mechanics, numerical modeling, or both. Thesecalculations are
26、 beyond the scope of this document.6. Basis of Application6.1 The following items are subject to contractual agree-ment between the parties using or referencing this practice.6.2 Personnel QualificationIf specified in the contractualagreement, personnel performing examinations to this standardshall
27、be qualified in accordance with a nationally and interna-tionally recognized NDT personnel qualification practice orstandard such asANSI/ASNT CP-189, SNT-TC-1A, NAS-410,ISO 9712, or a similar document and certified by the employeror certifying agency, as applicable. The practice or standardused and
28、its applicable revision shall be identified in thecontractual agreement between the using parties.6.3 Qualification of Nondestructive Testing AgenciesIfspecified in the contractual agreement, NDT agencies shall bequalified and evaluated as described in Specification E543. Theapplicable edition of Sp
29、ecification E543 shall be specified inthe contractual agreement.6.4 Extent of ExaminationThe extent of examination in-cludes the entire tube bundle unless otherwise specified.6.5 Reexamination of Repaired/Re-cleaned Worked TubesReexamination of repaired/re-cleaned items is not addressed inthis pract
30、ice and if required shall be specified in the contractualagreement.7. Apparatus7.1 Acoustic Pulse Reflectometry equipment includes:7.1.1 An APR probe with:7.1.1.1 A wideband sound source, usually a loudspeaker,capable of producing frequencies typically in the range of 0 to8 kHz. Pulse width should b
31、e short enough to distinguishbetween reflections generated by flaws located at a mutualdistance defined by practical requirements of the test. Thesound source level should be high enough to ensure that theweakest reflected signal of interest is above the backgroundnoise level.7.1.1.2 A probe-to-tube
32、 adaptor for matching between theprobe diameter and the ID of the tube under inspection.7.1.1.3 A microphone for measuring reflected sound waves.7.1.2 A main unit that:7.1.2.1 Generates and amplifies electric signals, typicallyperformed by a processor, Digital-to-Analog Converter (DAC)and amplifier.
33、7.1.2.2 Sends the generated electric signals to the probessound source.7.1.2.3 Records signals produced by reflected waves andcaptured by the microphone in a format suitable for evaluation,typically performed by a preamplifier, Analog-to-Digital Con-verter (ADC) and a processor.7.1.2.4 Stores and di
34、splays measured data.7.1.2.5 Optionally analyzes and interprets the measureddata.8. Calibration8.1 System calibration shall include the complete APRexamination system and performed annually or prior to the firstuse.E2906/E2906M 1828.2 Any change of the probe, extension cables, acousticpulse reflecto
35、metry instrument, computer, or other recordinginstruments shall require recalibration of the system, andrecalibration shall be noted on the report.8.3 Should the system be found to be out of calibrationduring the examination, it shall be recalibrated. The recalibra-tion shall be noted on the report.
36、 All tubes examined since thelast valid calibration shall be reexamined.9. System Setup and Performance Verification9.1 System setup and performance verification shall beperformed prior to conducting APR examination.9.1.1 After setup a hardware test shall be conducted to makesure that all components
37、 are working.Atest measurement shallbe performed on a sample tube, and basic properties of thesignal verified, such as signal amplitude and shape, to be withinthe specifications of the manufacturer.9.1.2 APR system setup performed by adjustment of outputgain to achieve the best SNR for the particula
38、r tube geometryand noise level. This is done by increasing output gain in steps.The output gain level is considered optimal when the noisecreated by a nonlinear distortion becomes larger than thebackground noise.9.1.3 Performance verification of the system shall be con-ducted to ensure detection and
39、 sizing of flaws or blockages ofinterest prior to every APR examination. Performance verifi-cation can be done by examination of reference tube bundles.Atypical reference tube bundle will include both flawless tubesand tubes with flaws including blockages, pits, holes andend-of-tube erosions. Perfor
40、mance verification is done byexamination of the tubes in the bundle and identification of allflaws.An example of a reference tube bundle is provided in theNon-Mandatory Appendix.10. Procedure10.1 Preparation for Examination:10.1.1 Verify that tube surfaces are sufficiently clean forconducting APR ex
41、amination so possible discontinuities aresurface open.10.1.2 Blow out residual water.10.2 Perform measurements on each tube of the bundle byinserting the APR probes adaptor into the tube end, triggeringthe sound source, measuring reflections and storing measuredsignals into memory. Good sealing betw
42、een the adaptor and thetube end should be ensured.10.3 Signal Analysis:10.3.1 Perform high pass signal filtering in the case of lowfrequency drift in the signal caused by elevated low frequencynoise.10.3.2 Perform low pass signal filtering in the case of highfrequency signal oscillations caused by e
43、levated high fre-quency noise.10.3.3 It is recommended to subtract the reference signalfrom all the measured signals to eliminate reflections caused bystructural features, the probe or the adaptor, that are not flaw orblockage related.10.3.4 Indication DetectionDetect indications of flaws orblockage
44、s by considering recorded signals in the time domainand selecting positive and negative deviations of the signalwhich are above the noise level.10.3.5 Indication LocationEvaluate location of detectedindications by considering time-of-flight of the wave, speed ofsound, adjusted for temperature from t
45、he probe to the source ofreflection and back. Data shall be recorded as each tube ismeasured.10.4 Indication IdentificationIt is possible to identify thetype of the detected indication (through-wall holes, partial wallloss, tube blockages) by considering the form of the reflectedsignal (see Appendix
46、 X1).10.5 Indication Size CharacterizationWhen special meth-ods of signal analysis are developed, it is possible to evaluatesize of the detected indication by considering amplitude of thepositive and negative deviations of the signal and time durationof the signal deviation. Particularly, in the cas
47、e of blockage,APR can provide information about cross-section reduction. Inthe case of through-wall hole, it is possible to determine holediameter and in the case of wall thickness reduction as a resultof pitting or erosion, it is possible to evaluate overall, integralwall loss in the tube cross-sec
48、tion.11. Report11.1 A report of the examination shall be generated. Thereport shall include, at a minimum, the following information:11.1.1 Owner, location, type, serial number, and identifica-tion of component examined,11.1.2 Size, wall thickness, material type, and configurationof installed tubes,
49、11.1.3 Tube numbering system,11.1.4 Extent of examination or tubes examined and lengthof tubes scanned,11.1.5 Personnel performing the examination, and11.1.6 Date of examination.11.1.7 Models, types, and serial numbers of components ofthe acoustic pulse reflectometry system:11.1.7.1 Probe-to-tube adapter model/type and extensionlength,11.1.7.2 All instrument settings,11.1.7.3 Signal-to-noise ratio,11.1.7.4 Output gain,11.1.7.5 Serial number(s) of reference tube(s),11.1.7.6 Procedure usedidentification and revision, and11.1.8 Acceptance criteria used.11.1.9
