1、Designation: E 1419 02bStandard Test Method forExamination of Seamless, Gas-Filled, Pressure VesselsUsing Acoustic Emission1This standard is issued under the fixed designation E 1419; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method provides guidelines for acoustic emis-sion (AE) examinations of seamless pressure vesse
3、ls (tubes) ofthe type used for distribution or storage of industrial gases.1.2 This test method requires pressurization to a levelgreater than normal use. Pressurization medium may be gas orliquid.1.3 This test method does not apply to vessels in cryogenicservice.1.4 The AE measurements are used to
4、detect and locateemission sources. Other nondestructive test (NDT) methodsmust be used to evaluate the significance of AE sources.Procedures for other NDT techniques are beyond the scope ofthis test method. See Note 1.NOTE 1Shear wave, angle beam ultrasonic examination is commonlyused to establish c
5、ircumferential position and dimensions of flaws thatproduce AE.1.5 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use
6、. 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. Specific precau-tionary statements are given in Section 7.2. Referenced Documents2.1 ASTM Standards:E 543 Practice for
7、 Agencies Performing NondestructiveTesting2E 650 Guide for Mounting Piezoelectric Acoustic EmissionSensors2E 976 Guide for Determining the Reproducibility of Acous-tic Emission Sensor Response2E 1316 Terminology for Nondestructive Examinations2E 2223 Practice for Examination of Seamless, Gas-filled,
8、Steel Pressure Vessels Using Angle Beam Ultrasonics22.2 ASNT Standards:3Recommended Practice SNT-TC-1A for NondestructiveTesting Personnel Qualification and CertificationANSI/ASNT CP-189 Standard for Qualification and Certi-fication of Nondestructive Testing Personnel2.3 Code of Federal Regulations:
9、Section 49, Code of Federal Regulations, Hazardous Mate-rials Regulations of the Department of Transportation,Paragraphs 173.34, 173.301, 178.36, 178.37, and 178.4542.5 Compressed Gas Association Standard:Pamphlet C-5 Service Life, Seamless High Pressure Cylin-ders52.4 AIA Document:NAS-410 Certifica
10、tion and Qualification of NondestructiveTesting Personnel63. Terminology3.1 DefinitionsSee Terminology E 1316 for general ter-minology applicable to this test method.3.2 Definitions of Terms Specific to This Standard:3.2.1 fracture critical flawa flaw that is large enough toexhibit unstable growth a
11、t service conditions.3.2.2 marked service pressurepressure for which a vesselis rated. Normally this value is stamped on the vessel.3.2.3 normal fill pressurelevel to which a vessel is pres-surized. This may be greater, or may be less, than markedservice pressure.1This test method is under the juris
12、diction of ASTM Committee E07 onNondestructive Testing and is the direct responsibility of Subcommittee E07.04 onAcoustic Emission Method.Current edition approved December 10, 2002. Published February 2003. Origi-nally approved in 1991. Last previous edition approved in 2002 as E 1419 02a.2Annual Bo
13、ok of ASTM Standards, Vol 03.03.3Available from American Society for Nondestructive Testing, 1711 ArlingatePlaza, P.O. Box 28518, Columbus, OH 43228-0518.4Available from Superintendent of Documents, U.S. Government PrintingOffice, Washington, DC 20402.5Available from Compressed Gas Association, Inc.
14、, 1235 Jefferson DavisHighway, Arlington, VA 22202.6Available from Aerospace Industries Association of America, Inc., 1250 EyeSt., NW, Washington, DC 200051Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Summary of Test Method4.1 T
15、he AE sensors are mounted on a vessel, and emissionis monitored while the vessel is pressurized above normal fillpressure.4.2 Sensors are mounted at each end of the vessel and areconnected to an acoustic emission signal processor. The signalprocessor uses measured times of arrival of emission bursts
16、 todetermine linear location of emission sources. If measuredemission exceeds a prescribed level (that is, specific locationsproduce enough events), then such locations receive secondary(for example, ultrasonic) examination.4.3 Secondary examination establishes presence of flawsand measures flaw dim
17、ensions.4.4 If flaw depth exceeds a prescribed limit (that is, aconservative limit that is based on construction material, wallthickness, fatigue crack growth estimates, and fracture criticalflaw depth calculations), then the vessel must be removed fromservice.5. Significance and Use5.1 Because of s
18、afety considerations, regulatory agencies(for example, U.S. Department of Transportation) requireperiodic examinations of vessels used in transportation ofindustrial gases (see Section 49, Code of Federal Regulations).The AE examination has become accepted as an alternative tothe common hydrostatic
19、proof examination. In the commonhydrostatic examination, volumetric expansion of vessels ismeasured.5.2 An AE examination should not be used for a period ofone year after a common hydrostatic examination. See Note 2.NOTE 2The Kaiser effect relates to decreased emission that isexpected during a secon
20、d pressurization. Common hydrostatic examina-tions use a relatively high test pressure (167 % of normal servicepressure). (See Section 49, Code of Federal Regulations.) If an AEexamination is performed too soon after such a pressurization, the AEresults will be insensitive to a lower test pressure (
21、that is, the lowerpressure that is associated with an AE examination).5.3 Pressurization:5.3.1 General practice in the gas industry is to use lowpressurization rates. This practice promotes safety and reducesequipment investment. The AE examinations should be per-formed with pressurization rates tha
22、t allow vessel deformationto be in equilibrium with the applied load. Typical currentpractice is to use rates that approximate 500 psi/h (3.45MPa/h).5.3.2 Gas compressors heat the pressurizing medium. Afterpressurization, vessel pressure may decay as gas temperatureequilibrates with ambient conditio
23、ns.5.3.3 Emission from flaws is caused by flaw growth andsecondary sources (for example, crack surface contact andcontained mill scale). Secondary sources can produce emissionthroughout vessel pressurization.5.3.4 When pressure within a vessel is low, and gas is thepressurizing medium, flow velociti
24、es are relatively high. Flow-ing gas (turbulence) and impact by entrained particles canproduce measurable emission. Considering this, acquisition ofAE data may commence at some pressure greater than startingpressure (for example,13 of maximum examination pressure).5.3.5 Maximum Test PressureSerious
25、flaws usually pro-duce more acoustic emission (that is, more events, events withhigher peak amplitude) from secondary sources than from flawgrowth. When vessels are pressurized, flaws produce emissionat pressures less than normal fill pressure. A maximum exami-nation pressure that is 10 % greater th
26、an normal fill pressureallows measurement of emission from secondary sources inflaws and from flaw growth.5.3.6 Pressurization SchedulePressurization should pro-ceed at rates that do not produce noise from the pressurizingmedium and that allow vessel deformation to be in equilibriumwith applied load
27、. Pressure holds are not necessary; however,they may be useful for reasons other than measurement of AE.5.4 Excess background noise may distort AE data or renderthem useless. Users must be aware of the following commonsources of background noise: high gas-fill rate (measurableflow noise); mechanical
28、 contact with the vessel by objects;electromagnetic interference (EMI) and radio frequency inter-ference (RFI) from nearby broadcasting facilities and fromother sources; leaks at pipe or hose connections; and airbornesand particles, insects, or rain drops. This test method shouldnot be used if backg
29、round noise cannot be eliminated orcontrolled.6. Basis of Application6.1 Personnel Qualification6.1.1 If specified in the contractual agreement, personnelperforming examinations to this standard shall be qualified inaccordance with a nationally recognized NDT personnel quali-fication practice or sta
30、ndard such as ANSI/ASNT-CP-189,SNT-TC-1A, NAS-410, or a similar document and certified bythe employer or certifying agency, as applicable. The practiceor standard used and its applicable revision shall be identifiedin the contractual agreement between the using parties.6.2 Qualification of Nondestru
31、ctive Agencies6.2.1 If specified in the contractual agreement, NDT agen-cies shall be qualified and evaluated as described in PracticeE 543. The applicable edition of Practice E 543 shall bespecified in the contractual agreement.6.3 Time of Examination6.3.1 The timing of examination shall be in acco
32、rdance with5.2 unless otherwise specified.6.4 Extent of Examination6.4.1 The extent of examination includes the entire pressurevessel unless otherwise specified.6.5 Reporting Criteria/Acceptance Criteria6.5.1 Reporting criteria for the examination results shall bein accordance with Section 11 unless
33、 otherwise specified.6.5.2 Since acceptance criteria (for example, reference ra-diographs) are not specified in this standard, they shall bespecified in the contractual agreement.6.6 Reexamination of Repaired/Reworked Items6.6.1 Reexamination of repaired/reworked items is not ad-dressed in this stan
34、dard and if required shall be specified in thecontractual agreement.E 1419 02b27. Apparatus7.1 Essential features of the apparatus required for this testmethod are provided in Fig. 1. Full specifications are in AnnexA1.7.2 Couplant must be used to acoustically connect sensorsto the vessel surface. A
35、dhesives that have acceptable acousticproperties, and adhesives used in combination with traditionalcouplants, are acceptable.7.3 Sensors may be held in place with magnets, adhesivetape, or other mechanical means.7.4 The AE sensors are used to detect strain-induced stresswaves produced by flaws. Sen
36、sors must be held in contact withthe vessel wall to ensure adequate acoustic coupling.7.5 A preamplifier may be enclosed in the sensor housing orin a separate enclosure. If a separate preamplifier is used, cablelength, between sensor and preamp, must not exceed 6 ft (1.83m).7.6 Power/signal cable le
37、ngth (that is, cable betweenpreamp and signal processor) shall not exceed 500 ft (152.4 m).See A1.5.7.7 Signal processors are computerized instruments withindependent channels that filter, measure, and convert analoginformation into digital form for display and permanent stor-age. A signal processor
38、 must have sufficient speed and capacityto independently process data from all sensors simultaneously.The signal processor should provide capability to filter data forreplay. A printer should be used to provide hard copies ofexamination results.7.7.1 A video monitor should display processed examina-
39、tion data in various formats. Display format may be selected bythe equipment operator.7.7.2 A data storage device, such as a floppy disk, may beused to provide data for replay or for archives.7.7.3 Hard copy capability should be available from agraphics/line printer or equivalent device.8. Safety Pr
40、ecautions8.1 As in any pressurization of metal vessels, ambienttemperature should not be below the ductile-brittle transitiontemperature of the pressure vessel construction material.9. Calibration and Standardization9.1 Annual calibration and verification of pressure trans-ducer, AE sensors, preampl
41、ifiers (if applicable), signal proces-sor (particularly the signal processor time reference), and AEelectronic waveform generator should be performed. Equip-ment should be adjusted so that it conforms to equipmentmanufacturers specifications. Instruments used for calibra-tions must have current accu
42、racy certification that is traceableto the National Institute for Standards and Technology (NIST).9.2 Routine electronic evaluations must be performed anytime there is concern about signal processor performance. AnAE electronic waveform generator should be used in makingevaluations. Each signal proc
43、essor channel must respond withpeak amplitude reading within 62 dBV of the electronicwaveform generator output.9.3 A system performance verification must be conductedimmediately before, and immediately after, each examination.A performance verification uses a mechanical device to inducestress waves
44、into the vessel wall at a specified distance fromeach sensor. Induced stress waves stimulate a sensor in thesame way as emission from a flaw. Performance verificationsverify performance of the entire system (including couplant).9.3.1 The preferred technique for conducting a performanceverification i
45、s a pencil lead break (PLB). Lead should bebroken on the vessel surface no less than 4 in. (10.16 cm) fromthe sensor. The 2H lead, 0.3-mm diameter, 3-mm long shouldbe used (see Fig. 4 of Guide E 976).9.3.2 Auto Sensor Test (AST). An electromechanical devicesuch as a piezoelectric pulser (and sensor
46、which contains thisfunction) can be used in conjunction with pencil lead break(9.3.1) as a means to assure system performance. This devicecan be used to replace the PLB post examination, systemperformance verification (9.3).10. Procedure10.1 Visually examine accessible exterior surfaces of thevessel
47、. Note observations in examination report.10.2 Isolate vessel to prevent contact with other vessels,hardware, and so forth. When the vessel cannot be completelyisolated, indicate, in the examination report, external sourceswhich could have produced emission.10.3 Connect fill hose and pressure transd
48、ucer. Eliminateany leaks at connections.10.4 Mount an AE sensor at each end of each tube. Useprocedures specified in Guide E 650. Sensors must be at thesame angular position and should be located at each end of thevessel so that the AE system can determine axial locations ofsources in as much of the
49、 vessel as possible.10.5 Adjust signal processor settings. See Appendix X1 forexample.10.6 Perform a system performance verification at eachsensor (see 9.3). Verify that peak amplitude is greater than aspecified value (see Table X1.2). Verify that the AE systemdisplays a correct location (see Note 3) for the mechanicaldevice that is used to produce stress waves (see 9.4 and TableX1.2). Prior to pressurization, verify that there is no back-ground noise above the signal processor threshold setting.NOTE 3If desired location accuracy cannot be attained with sensors atFIG. 1 Esse
