1、Designation: E2863 12Standard Practice forAcoustic Emission Examination of Welded Steel SpherePressure Vessels Using Thermal Pressurization1This standard is issued under the fixed designation E2863; the number immediately following the designation indicates the year oforiginal adoption or, in the ca
2、se of revision, 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. Scope*1.1 This practice is commonly used for periodic inspectionand testing of welded steel gaseous
3、 spheres (bottles) is theacoustic emission (AE) method. AE is used in place ofhydrostatic volumetric expansion testing. The periodic inspec-tion and testing of bottles by AE testing is achieved withoutdepressurization or contamination as is required for hydrostaticvolumetric expansion testing.1.2 Th
4、e required test pressurization is achieved by heatingthe bottle in an industrial oven designed for this purpose. Themaximum temperature needed to achieve the AE test pressureis #250F (121C).1.3 AE monitoring of the bottle is performed with multiplesensors during the thermal pressurization.1.4 This p
5、ractice was developed for periodic inspection andtesting of pressure vessels containing Halon (UN 1044), whichis commonly used aboard commercial aircraft for fire suppres-sion. In commercial aircraft, these bottles are hermeticallysealed by welding in the fill port. Exit ports are opened byexplosive
6、ly activated burst disks. The usage of these pressurevessels in transportation is regulated under US Department ofTransportation (DOT), Code of Federal Regulations CFR 49.ADOT special permit authorizes the use of AE testing forperiodic inspection and testing in place of volumetric expan-sion and vis
7、ual inspection. These bottles are spherical withdiameters ranging from 5 to 16 in. (127 to 406 mm).1.5 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are mathemati-cal conversions to SI units that are provided for informationonly and are not
8、considered standard.1.6 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
9、 use. Specific precau-tionary statements are given in Section 8.2. Referenced Documents2.1 ASTM Standards:2E543 Specification for Agencies Performing Nondestruc-tive TestingE650 Guide for Mounting Piezoelectric Acoustic EmissionSensorsE976 Guide for Determining the Reproducibility of Acous-tic Emiss
10、ion Sensor ResponseE1316 Terminology for Nondestructive ExaminationsE2075 Practice for Verifying the Consistency of AE-SensorResponse Using an Acrylic RodE2374 Guide for Acoustic Emission System PerformanceVerification2.2 ASNT Standards:3SNT-TC-1A Recommended Practice for NondestructiveTesting Perso
11、nnel Qualification and CertificationANSI/ASNT CP-189 Standard for Qualification and Certi-fication of Nondestructive Testing Personnel2.3 Code of Federal Regulations:Section 49 Code of Federal Regulations, Hazardous Mate-rials Regulations of the Department of Transportation,Paragraphs 173.34, 173.30
12、1, 178.36, 178.37, and 178.4542.4 Compressed Gas Association Standard:Pamphlet C-5 Service Life, Seamless High Pressure Cylin-ders53. Terminology3.1 DefinitionsSee Terminology E1316 for general termi-nology applicable to this test method.3.2 Definitions of Terms Specific to This Standard:3.2.1 marke
13、d service pressurepressure for which a vesselis rated. Normally, this value is stamped on the vessel1This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.04 onAcoustic Emission Method.Current edition approved Ju
14、ne 15, 2012. Published July 2012. Originallyapproved in 2011. Last previous edition approved in 2011 as E2863 - 11.DOI:10.1520/E2863-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume in
15、formation, refer 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 U.S. Government Printing Office Superintendent of Documents,732
16、 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.5Available from Compressed Gas Association (CGA), 4221 Walney Rd., 5thFloor, Chantilly, VA 20151-2923, http:/.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr
17、Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Summary of Practice4.1 Acoustic emission (AE) sensors are mounted on apressure vessel, and emission is monitored while the pressurevessel is heated to a pre-determined temperature for achievingthe desired AE test pressure.
18、 The elevated temperature resultsin expansion of the gaseous component and causes the increaseof the internal pressure. This increasing pressure applies stressin the pressure vessel wall. The ultimate pressure is calculatedbased on the contents of the pressure vessel (bottle) andmaximum operating te
19、mperature that bottle has been exposed(for example, during fast filling).4.2 Sensors are mounted in at least six positions on thevessel and are connected to an acoustic emission signalprocessor. The signal processor uses measured times of arrivalof emission bursts to determine the location of emissi
20、onsources on the vessels surface. The locations are continuallychecked for clustering. If a cluster grows large enough (refer toAppendix X1), and/or its behavior with increasing temperature(pressure) departs significantly from a linear increase (refer toAppendix X1), the vessel is declared unsatisfa
21、ctory for con-tinued service.4.3 Bottles that fail this AE examination procedure cannotbe subjected to a secondary examination (for example, hydro-static volumetric expansion test) because the AE test is themore sensitive test. When a bottle has been rejected by an AEtest, it should be rendered unse
22、rviceable.4.4 Once a bottle has reached a temperature of 110F(43.3C) during anAE examination, it may not be re-examinedfor a period of six months unless the physical state of the bottlehas been changed by refilling or external damage.5. Significance and Use5.1 Because of safety considerations, regul
23、atory agencies(for example, U.S. Department of Transportation) requireperiodic tests of pressurized vessels used in commercialaviation. (see Section 49, Code of Federal Regulations). AEesting has become accepted as an alternative to the commonhydrostatic proof test.5.2 An AE test should not be condu
24、cted for a period of oneyear after a common hydrostatic test. See Note 1.NOTE 1The Kaiser effect relates to the irreversibility of acousticemission which results in decreased emission during a second pressuriza-tion. Common hydrostatic tests use a relatively high test pressure (200 %of normal servic
25、e pressure). (See Section 49, Code of Federal Regula-tions.) If an AE test is performed too soon after such a hydrostaticpressurization, the AE results will be insensitive below the previousmaximum test pressure.5.3 Acoustic Emission is produced when an increasingstress level in a material causes cr
26、ack growth in the material orstress related effects in a corroded surface (for example, crackgrowth in or between metal crystallites or spalling and crackingof oxides and other corrosion products).5.4 While background noise may distort AE data or renderit useless, heating the vessels inside an indus
27、trial oven is analmost noise free method of pressurization. Further, sourcelocation algorithms using over-determined data sets will oftenallow valid tests in the presence of otherwise interfering noisesources. Background noise should be reduced or controlled butthe sudden occurrence of such noise do
28、es not necessarilyinvalidate a test.6. Basis of Application6.1 The following items are subject to contractual agree-ment between the parties using or referencing this standard.6.2 Personnel Qualification:6.2.1 If specified in the contractual agreement, personnelperforming examinations to this standa
29、rd shall be qualified inaccordance with a nationally or internationally recognizedNDT personnel qualification practice or standard such asANSI/ASNT-CP-189, SNT-TC-1A, NAS-410, or a similardocumented and certified by the employer or certifying agency,as applicable. The practice or standard used and i
30、ts applicablerevision shall be identified in the contractual agreement be-tween the using parties.6.2.2 The NDT personnel shall be qualified in accordancewith a nationally recognized NDT personnel qualificationpractice or standard such as ANSI/ASNT CP-189, SNT-TC-1A, or a similar document. The pract
31、ice or standard used andits applicable revision shall be specified in the contractualagreement 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. Thea
32、pplicable edition of Specification E543 shall be specified inthe contractual agreement.6.4 Procedures and TechniquesThe procedures and tech-niques to be utilized shall be as specified in the contractualagreement.6.5 Surface PreparationThe pre-examination surfacereparation criteria shall be in accord
33、ance with 10.2.1, unlessotherwise specified.6.6 Reporting Criteria/Acceptance CriteriaReporting cri-teria for the examination results shall be in accordance withAppendix X1 unless otherwise specified.7. Apparatus7.1 Essential features of the apparatus required for thispractice are provided in Fig. 1
34、. Full specifications are in AnnexA1.7.2 A couplant can be used between the sensors and vesselwall. The small diameter of the sensor and significant contactpressure reduces the requirement for a couplant, but it is oftenuseful when positioning a vessel in the test frame to avoidinterfering features
35、on its surface or when the first ASTcoupling test has failed.7.3 AE Sensors are held in place by means of spring-loadedrods mounted to the test frame.7.4 The AE sensors are continuously monitored throughoutthe pressurization.7.5 A preamplifier for each sensor is located outside theoven. The sensor c
36、able length must not exceed 6 ft (2 m).7.6 The signal processor is a computerized instrument withindependent channels that filter, measure, and convert analoginformation into digital form for analysis, display and perma-nent storage. A signal processor must have sufficient speed andE2863 122capacity
37、 to independently process data from all sensors simul-taneously. The signal processor must be programed to locatethe sources on the surfaces of the vessel and to detect clusteringof the sources. The instrument must be capable of reading thevessel temperature and controlling the industrial oven. It m
38、ustalso conduct and interpret AST tests both before and after thethermal pressurization.7.6.1 Hard copy capability should be available from aprinter or equivalent device.8. Safety Precautions8.1 This examination involves pressurization of sealed ves-sels by heating. When a significant defect is dete
39、cted, there isno method of decreasing the internal pressure except cooling ofthe vessel. It is imperative that the heating cease as soon as asignificant defect is identified. This requires that theAE systemhave complete control over the examination, including the preand post-examination system perfo
40、rmance verification; theoven heaters; detecting, identifying and classifying defects andthe determination of when the defect behavior requires the testto be stopped, decreasing the possibility of an explosion. Theoperator has no control over the carrying out of the test,including analysis and gradin
41、g of defects or when to stop thetest for safety reasons.8.2 Maximum temperature of the ovens heating elementsurface must remain below 800F (427C). This will preventthermal decomposition of the HALON 1301 into toxic byprod-ucts in the event of an accidental release.8.3 HALON 1301, itself, has low tox
42、icity but a rapid releaseof pressure could rupture the oven and/or present an asphyxi-ation hazard in a small enclosed region.FIG. 1 AE System Block DiagramFIG. 2 AE Sensor Holding Fixture (sensors on the head of thespring loaded rods)E2863 1239. Calibration and Verification9.1 Annual calibration an
43、d verification of AE sensors,preamplifiers, signal processor (particularly the signal proces-sor time reference), and AE electronic waveform generator,should be performed. Equipment should be adjusted so that itconforms to equipment manufacturers specifications. Instru-ments used for calibrations mu
44、st have current accuracy certi-fication that is traceable to the National Institute for Standardsand Technology (NIST).9.2 Routine electronic evaluations must be performedwithin 30 days prior to a test or any time there is concern aboutsignal processor performance. An AE electronic waveformgenerator
45、 should be used in making evaluations. Each signalprocessor channel must respond with peak amplitude readingwithin 62 dB of the electronic waveform generator output.9.3 Routine sensor performance verification must be per-formed within 30 days prior to the test date and any time thereis concern for s
46、ensor performance. A procedure for sensorperformance verification is found in Practice E2075.9.4 A system performance check must be conducted as partof the AE test immediately before and after thermal pressur-ization. A performance check uses a feature of the AE systemknown as “Auto Sensor Test (AST
47、).” When initiated, the ASTfeature injects a voltage pulse into one sensor at a time. Theresulting stress wave travels from the pulsing sensor to theremaining sensors, through the vessel metal surface and thepeak amplitude of each is recorded. During pre-examinationAST, any sensor, in which the aver
48、age of the amplitudesdetected by a sensor falls outside +6 dB of the average of theentire set, will cause the AST test to fail. When the pre-examination AST is failed, the sensors must be checked andreseated. Only when all sensors are within +6 dB of theaverage can the examination begin. If the post
49、 examinationAST fails, the senior engineer in charge of the system mustexamine the stored data to determine whether the AE exami-nation is valid.10. Procedure10.1 The initiation and completion of the examinationprocedure involves several steps which must be completed bythe operator. The actual heating of the vessel is automated andunder the control of the AE system. The steps which must beconducted by the operator and the function of the automatedAE system follow:10.2 Pre-Examination Operator Procedure:10.2.1 Visually examine the exterior surfaces of
