1、Designation: E 1067 07Standard Practice forAcoustic Emission Examination of Fiberglass ReinforcedPlastic Resin (FRP) Tanks/Vessels1This standard is issued under the fixed designation E 1067; the number immediately following the designation indicates the year oforiginal adoption or, in the case of re
2、vision, 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 practice covers acoustic emission (AE) examina-tion or monitoring of fiberglass-reinforced p
3、lastic (FRP) tanks-vessels (equipment) under pressure or vacuum to determinestructural integrity.1.2 This practice is limited to tanks-vessels designed tooperate at an internal pressure no greater than 0.44 MPaabsolute (65 psia) above the static pressure due to the internalcontents. It is also appli
4、cable for tanks-vessels designed forvacuum service with differential pressure levels between 0 and0.06 MPa (0 and 9 psi).1.3 This practice is limited to tanks-vessels with glasscontents greater than 15 % by weight.1.4 This practice applies to examinations of new and in-service equipment.1.5 The valu
5、es stated in SI units are to be regarded asstandard. The inch-pound units in parentheses may be approxi-mate.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
6、 and health practices and determine the applica-bility of regulatory limitations prior to use. (For more specificsafety precautionary information see 8.1.)2. Referenced Documents2.1 ASTM Standards:2D 883 Terminology Relating to PlasticsE 543 Specification for Agencies Performing Nondestruc-tive Test
7、ingE 650 Guide for Mounting Piezoelectric Acoustic EmissionSensorsE 750 Practice for CharacterizingAcoustic Emission Instru-mentationE 1316 Terminology for Nondestructive ExaminationsE 2374 Guide for Acoustic Emission System PerformanceVerification2.2 ANSI/ASNT Standards:SNT-TC-1A Recommended Practi
8、ce for NondestructiveTesting Personnel Qualification and Certification3ANSI/ASNT CP-189 Standard for Qualification and Certi-fication of Nondestructive Testing Personnel32.3 AIA Standard:NAS-410 Certification and Qualification of NondestructivePersonnel (Quality Assurance Committee)43. Terminology3.
9、1 Complete definitions of terms related to plastics andacoustic emission will be found in Terminology D 883 andE 1316.3.2 Definitions of Terms Specific to This Standard:3.2.1 count value Ncan evaluation criterion based on thetotal number of AE counts. (See A2.4 of Annex A2.)3.2.2 FRPfiberglass reinf
10、orced plastic, a glass-fiber poly-mer composite with certain mechanical properties superior tothose of the base resin.3.2.3 high-amplitude thresholda threshold for large am-plitude AE events. (See A2.3 of Annex A2.)3.2.4 low-amplitude thresholdthe threshold above whichAE counts (N) are measured. (Se
11、e A2.2 of Annex A2.)3.2.5 operating pressurethe pressure at the top of a vesselat which it normally operates. It shall not exceed the designpressure and it is usually kept at a suitable level below thesetting of the pressure-relieving devices to prevent theirfrequent opening.3.2.6 pressure, designth
12、e pressure used in design todetermine the required minimum thicknesses and minimummechanical properties.1This 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 approve
13、d Feb. 15, 2007. Published March 2007. Originallyapproved in 1985. Last previous edition approved in 2001 as E 1067 - 01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refe
14、r to the standards Document Summary page onthe ASTM website.3Available fromAmerican Society for NondestructiveTesting (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., Suit
15、e 1700,Arlington, VA22209-3928, http:/www.aia-aerospace.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.7 processora circuit that analyzes AE waveforms.(See Section 7 and A1.8.)3.2.8 summing amplifier (summer, mixer)an operat
16、ionalamplifier that produces an output signal equal to a weightedsum of the input signals.3.2.9 zonethe area surrounding a sensor from which AEcan be detected by that sensor.4. Summary of Practice4.1 This practice consists of subjecting equipment to in-creasing pressure or vacuum while monitoring wi
17、th sensorsthat are sensitive to acoustic emission (transient stress waves)caused by growing flaws. The instrumentation and techniquesfor sensing and analyzing AE data are described.4.2 This practice provides guidelines to determine the loca-tion and severity of structural flaws in FRP equipment.4.3
18、This practice provides guidelines forAE examination ofFRP equipment within the pressure range stated in 1.2.Maximum test pressure (or vacuum) for an FRP vessel will bedetermined upon agreement among user, manufacturer, or testagency, or a combination thereof. Pressure vessels having aninternal opera
19、ting pressure exceeding 0.2 MPa absolute (30psia), will normally be tested to 1.5 3 operating pressure.Atmospheric storage vessels will normally be tested undermaximum operating conditions. Pressure vessels having aninternal pressure between 0.1 and 0.2 MPa absolute (15 and 30psia), and vacuum vesse
20、ls having an external differentialpressure between 0 and 0.06 MPa (0 and 9 psi), will normallybe tested to pressures in the range from 1.0 to 1.5 3 operatingpressure.5. Significance and Use5.1 The AE examination method detects damage in FRPequipment. The damage mechanisms that are detected in FRPare
21、 as follows: resin cracking, fiber debonding, fiber pullout,fiber breakage, delamination, and bond failure in assembledjoints (for example, nozzles, manways, etc.). Flaws in un-stressed areas and flaws that are structurally insignificant willnot generate AE.5.2 This practice is convenient for on-lin
22、e use under oper-ating stress to determine structural integrity of in-serviceequipment usually with minimal process disruption.5.3 Indications located with AE should be examined byother techniques; for example, visual, ultrasound, dye pen-etrant, etc., and may be repaired and tested as appropriate.R
23、epair procedure recommendations are outside the scope ofthis practice.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 Qualification:6.2.1 If specified in the contractual agreement, personnelperf
24、orming examinations to this standard 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 similardocument and certified by the employer or certifying agency,as applicable. The
25、 practice or standard used and its applicablerevision shall be specified in the contractual agreement be-tween the using parties.6.3 Qualification of Nondestructive AgenciesIf specifiedin the contractual agreement, NDT agencies shall be qualifiedand evaluated as described in Practice E 543. The appl
26、icableedition of Practice E 543 shall be specified in the contractualagreement.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 surfacepreparation criteria shall be in accordance wi
27、th 9.2 unlessotherwise specified.6.6 Reporting Criteria/Acceptance CriteriaReporting cri-teria for the examination results shall be in accordance withSection 13 unless otherwise specified. Since acceptance criteriaare not specified in this practice, they shall be specified in thecontractual agreemen
28、t.7. Instrumentation7.1 The AE instrumentation consists of sensors, signalprocessors, and recording equipment. Additional informationon AE instrumentation can be found in Practice E 750.7.2 Instrumentation shall be capable of recordingAE countsand AE hits above the low-amplitude threshold, AE hits a
29、bovethe high-amplitude threshold within specific frequency ranges,and having sufficient channels to localize AE sources in realtime. It may incorporate (as an option) peak-amplitude detec-tion for each input channel or for groups of channels. Hitdetection is required for each channel. An AE hit ampl
30、itudemeasurement is recommended for sensitivity verification (seeAnnexA2).Amplitude distributions are recommended for flawcharacterization. It is preferred thatAE instrumentation acquireand record count, hit, and amplitude information on a perchannel basis. The AE instrumentation is further describe
31、d inAnnex A1.7.3 Capability for measuring parameters such as time andpressure shall be provided. The pressure-vacuum in the vesselshould be continuously monitored to an accuracy of 62%ofthe maximum test value.8. Examination Preparations8.1 SafetyAll plant safety requirements unique to theexamination
32、 location shall be met.8.1.1 Protective clothing and equipment that is normallyrequired in the area in which the examination is beingconducted shall be worn.8.1.2 A fire permit may be needed to use the electronicinstrumentation.8.1.3 Precautions shall be taken to protect against theconsequences of c
33、atastrophic failure when pressure testing, forexample, flying debris and impact of escaping liquid. Pressur-izing under pneumatic conditions is not recommended exceptwhen normal service loads include either a superposed gaspressure or gas pressure only. Care shall be taken to avoidoverstressing the
34、lower section of the vessel when liquid testloads are used to simulate operating gas pressures.E10670728.1.4 Special safety precautions shall be taken when pneu-matic testing is required; for example, safety valves, etc.8.2 Vessel ConditioningThe operating conditions for ves-sels that have been stre
35、ssed previously shall be reduced prior toexamining in accordance with the schedule shown in Table 1.The maximum operating pressure or load in the vessel duringthe past year must be known in order to conduct the AEexamination properly.8.3 Vessel StressingArrangements should be made tostress the vesse
36、l to the operating pressure-load where possible.The stress rate shall be sufficient to expedite the examinationwith minimum extraneous noise. Holding stress levels is a keyaspect of an acoustic emission examination. Accordingly,provision must be made for holding the pressure-load atdesignated check
37、points.8.3.1 Atmospheric TanksProcess liquid is the preferred fillmedium for atmospheric tanks. If water must replace theprocess liquid, the designer and user shall be in agreement onthe procedure to achieve acceptable stress levels.8.3.2 Vacuum-Tank StressingA controllable vacuum-pump system is req
38、uired for vacuum tanks.8.3.3 Pressure-Vessel StressingWater is the preferred me-dium for pressure tanks. Safe means for hydraulically increas-ing the pressure under controlled conditions shall be provided.8.4 Tank SupportThe tank shall be examined in its oper-ating position and supported in a manner
39、 consistent with goodinstallation practice. Flat-bottomed tanks examined in otherthan the intended location shall be mounted on a pad (forexample, rubber on a concrete base or equivalent) to reducestructure-borne noise between the tank and base.8.5 EnvironmentalThe normal minimum acceptable ves-sel
40、wall temperature is 4C (40F).8.6 Noise ReductionNoise sources in the examinationfrequency and amplitude range, such as rain, spargers, andforeign objects contacting the tank, must be minimized sincethey mask the AE signals emanating from the structure. Theinlet should be at the lowest nozzle or as n
41、ear to the bottom ofthe vessel as possible, that is, below the liquid level. Liquidfalling, swirling, or splashing can invalidate data obtainedduring the filling phase.8.7 Power SupplyA stable grounded power supply, meet-ing the specification of the instrumentation, is required at theexamination sit
42、e.8.8 Instrumentation SettingsSettings will be determinedas described in Annex A2.9. Sensors9.1 Sensor MountingRefer to Practice E 650 for addi-tional information on sensor mounting. Location and spacingof the sensors are discussed in 9.5. Sensors shall be placed indesignated locations with a coupla
43、nt between the sensor andexamination article. One recommended couplant is silicone-stopcock grease. Care must be exercised to assure that ad-equate couplant is applied. Sensors shall be held in placeutilizing methods of attachment which do not create extraneoussignals. Methods of attachment using cr
44、ossed strips ofpressure-sensitive tape or suitable adhesive systems, may beconsidered. Suitable adhesive systems are those whose bond-ing and acoustic coupling effectiveness have been demon-strated. The attachment method should provide support for thesignal cable (and preamplifier) to prevent the ca
45、ble(s) fromstressing the sensor or pulling the sensor away from theexamination article causing loss of coupling.9.2 Surface ContactReliable coupling between the sensorand tank surface shall be assured and the surface of the vesselin contact with the sensor shall be clean and free of particulatematte
46、r. Sensors should be mounted directly on the tank surfaceunless integral waveguides shown by test to be satisfactory areused. Preparation of the contact surface shall be compatiblewith both sensor and structure modification requirements.Possible causes of signal loss are coatings such as paint anden
47、capsulants, surface curvature, and surface roughness at thecontact area.9.3 High-Frequency Sensor(See Annex A1.) Severalhigh-frequency channels are used for zone location of emissionsources. Greater attenuation of stress waves at higher frequen-cies result in smaller zones of sensitivity for high-fr
48、equencysensors.9.4 Low-Frequency Sensor(See Annex A1.) Low-frequency channels are less affected by attenuation; therefore,they can be used to identify flaws in a large zone. If significantactivity is detected on the low-frequency channels, and not onhigh-frequency channels, consideration should be g
49、iven torelocating high-frequency sensors. It should be noted, however,that low-frequency channels are more susceptible to back-ground noise.9.5 Locations and SpacingsLocations on the vessel shellare determined by the need to detect structural flaws at criticalsections; for example, high-stress areas, geometric discontinui-ties, nozzles, manways, repaired regions, support rings, andvisible flaws. Spacings are governed by the attenuation of theFRP material.9.5.1 Attenuation CharacterizationTypical signal propa-gation losses shall be determined according t
