1、Designation: E2598/E2598M 13Standard Practice forAcoustic Emission Examination of Cast Iron Yankee andSteam Heated Paper Dryers1This standard is issued under the fixed designation E2598/E2598M; the number immediately following the designation indicates the yearof original adoption or, in the case of
2、 revision, the year of 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. Scope*1.1 This practice provides guidelines for carrying out acous-tic emission (AE) examinations of Yan
3、kee and Steam HeatedPaper Dryers (SHPD) of the type to make tissue, paper, andpaperboard products.1.2 This practice requires pressurization to levels usedduring normal operation. The pressurization medium may behigh temperature steam, air, or gas. The dryer is also subjectedto significant stresses d
4、uring the heating up and cooling downperiods of operation. Acoustic Emission data maybe collectedduring these time periods but this testing is beyond the scopeof this document.1.3 The AE measurements are used to detect, as well as,localize emission sources. Other methods of nondestructivetesting (ND
5、T) may be used to further evaluate the significanceof acoustic emission sources.1.4 UnitsThe values stated in either SI units or inch-pound units are to be regarded as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the oth
6、er. Combiningvalues from the two systems may result in non-conformancewith the standards.1.5 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 practice
7、s and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A278/A278M Specification for Gray Iron Castings forPressure-Containing Parts for Temperatures Up to 650F(350C)E543 Specification for Agencies Performing NondestructiveTestingE569 Prac
8、tice for Acoustic Emission Monitoring of Struc-tures During Controlled StimulationE650 Guide for Mounting Piezoelectric Acoustic EmissionSensorsE976 Guide for Determining the Reproducibility of AcousticEmission Sensor ResponseE1316 Terminology for Nondestructive ExaminationsE2374 Guide for Acoustic
9、Emission System PerformanceVerification2.2 ASNT Standards:3SNT-TC-1A Recommended Practice for NondestructiveTesting PersonnelANSI/ASNT CP-189 Standard for Qualification and Certifi-cation of Nondestructive Testing Personnel3. Terminology3.1 DefinitionsSee Terminology E1316 for general termi-nology a
10、pplicable to this practice.4. Summary of Practice4.1 Each mounted sensor, on the cast iron vessel, monitorswhile the vessel is stationary and pressurized to normaloperating pressure. The vessel may be at ambient, or operating120C-230C 250F-450F temperature.4.2 Each mounted AE sensor is connected to
11、an acousticemission signal processor. After a monitoring period (up to 10minutes) and pre-examination sensor sensitivity checks, pres-surization can begin.4.3 Location4.3.1 Zone LocationEach channel shall have the samesystem examination threshold. A simulated AE source gener-ated anywhere on the ves
12、sel shall be detected by at least onesensor.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 approved Jan. 1, 2013. Published January 2013. Originallyapproved i
13、n 2007. Last previous edition approved in 2007 as E2598 - 07. DOI:10.1520/E2598_E2598-13.2For 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 to the standards Document Summ
14、ary page onthe ASTM website.3Available from American Society for Nondestructive Testing (ASNT), P.O. Box28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http:/www.asnt.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box
15、C700, West Conshohocken, PA 19428-2959. United States14.3.2 Source LocationAll location data resulting fromanalysis shall be presented in a manner consistent with thepreviously established calibration accuracy. The simulated AEsource generated in each structure mounted sensor array shallbe detected
16、by the minimum number of sensors required tolocate the source within 65 % of sensor spacing.4.4 Due to the potential for gasketed interfaces (at theheads/manway), multiple metal combinations (metalspray, caststeel-cast iron combinations), high vessel temperature, orrandom variations in the material
17、velocity of cast iron, accuratesource location (65 % sensor spacing) may not always bepossible.4.5 Once the AE sensor source is localized, further evalua-tion is begun by observing a “history” of events involving thearea Head tilt (corrosion induced head strain), leak repair,objects through the nip
18、(working contact with another roll),etc. This may give further direction to the selection of theNDE method to use for follow-up examination of the AEindication area.4.6 Secondary examination establishes presence of flawsand measures flaw dimensions.4.7 Cast iron Yankee dryers can be up to 6.7 m 22 f
19、t indiameter, 7.3 m 24 ft long, and weigh 90,000 Kg 200,000lb, or more. Vessel thickness measurements are available fromthe paper/tissue machine operator. Cast iron is a brittle metaland has no specific yield point. Yankee dryers must maintainspecific dimensional tolerances. When a pressurized Yanke
20、e orsteam heated paper dryer (SHPD) remains stationary, it fillswith condensate at a rapid rate. In an hour, a steam pressurizedYankee or SHPD can fill half way with condensate, doublingthe weight on the frame, and the floor. Some Yankee ownershave corporate requirements that a cast iron Yankee drye
21、rremain stationary for12 hour, then rotation is required.Permission is required, if the Yankee is to remain stationary formore time. This issue should be discussed with the responsibleperson prior to the examination.4.8 Yankee dryers operate under a heated hood. The hood isin close proximity to the
22、Yankee shell and allows only inchesof clearance for the top half of the vessel.4.9 Cast iron steam heated paper machine dryers are 1.8 m6 ft in diameter, or more, and may be 9 m 30 ft long.4.10 Gray cast iron experiences a continuing reduction inelastic modulus as it is stressed to increasing higher
23、 levels. It isprudent not to stress grey cast iron material beyond itsoperating stress level.4.11 Flaws to be found are the same as those in any cast andmachined product. Attempts have been made to characterizestrength properties of cast irons in compact tension tests. In aTAPPI sponsored laboratory
24、 study, two out of three cast ironcompact tension specimens experienced unplanned failures.From that experience it was cautioned that “cracks initiated andgrew faster than expected resulting in brittle fracture before theprocess could be halted. The failure of these two couponsdemonstrated the rate
25、in which cracks can grow in thesematerials and the materials inability to stop a crack once itbegins to grow. In each case, crack advance was extremelyrapid and without warning.44.12 Maximum Examination PressureMaximum Allow-able Working Pressure for cast iron vessels is set based onASME (Section VI
26、II) pressure calculations based on thickness,radius, and material strength values, and will not exceed 11 bar160 psi and 230C 450F (A278/A278M). When vessels arepressurized, anomalies produce emission at pressures less thannormal fill pressure. Historically, if there is damage in a castiron pressure
27、 boundary, AE activity will begin at load/stresslevels less than 50 % of operating. Defects as small as 3 mm18 in. have been found using AE, during steam pressurizationto operating pressure.4.13 Pressure increments should not exceed 350 millibar/minute 5 psi/minute. If pressurization medium is to be
28、 steam,the Yankee should have been through the warm-up process.4.14 Yankee dryers may receive a subsequent examination,if necessary, after the Yankee is rotated to remove anycondensate present.4.15 Pressurization SchedulePressurization should pro-ceed at rates that allow achieving maximum examinatio
29、npressure within a 30 minute period. During pressurization,pressure holds are not necessary; however, they may be usefulfor reasons other than measurement of AE. Pressure hold uponachieving maximum examination pressure may be up to 30minutes.4.16 Excess background noise may distort AE data or render
30、the AE measurements useless. Users must be aware of thefollowing common sources of background noise: (measurablefilling or flow noise); mechanical contact with the vessel byobjects; electromagnetic interference (EMI) from cranes, andradio frequency interference (RFI) from nearby broadcastingfaciliti
31、es and from other sources; leaks at pipe or hoseconnections, or rain drops. This practice should not be used ifbackground noise cannot be eliminated or controlled.4.17 Other nondestructive test methods may be used toevaluate the significance of AE sources. Magnetic particle,ultrasonic, and radiograp
32、hic examinations have been used toestablish circumferential position, depth, and dimensions offlaws that produce AE. Procedures for using other NDTmethods are beyond the scope of this practice.5. Significance and Use5.1 Cast iron Yankee dryers can be up to 6.7 m 22 ft indiameter, 7.3 m 24 ft long, a
33、nd weigh 91,000 Kg 100 tons,or more (refer to Fig. 1). Vessel thickness measurements areavailable from the paper/tissue machine operator. Cast iron is abrittle metal and has no specific yield point. Yankee dryersmust maintain specific dimensional tolerances. When a pres-surized Yankee or steam heate
34、d paper dryer (SHPD) remainsstationary, it fills with condensate at a rapid rate. In an hour, asteam pressurized Yankee or SHPD can fill half way withcondensate, doubling the weight on the frame, and the floor.4Alleveto, C., and Williams D., Acoustic Emission Evaluation of Yankee DryerShell Material
35、, 1991 TAPPI Engineering Conference Proceedings, pages 475-480.E2598/E2598M 132Some Yankee owners have corporate requirements that a castiron Yankee dryer remain stationary for12 hour, then rotationis required. Permission is required, if the Yankee is to remainstationary for more time. This issue sh
36、ould be discussed withthe responsible person prior to the examination.5.2 Yankee dryers operate under a heated hood. The hood isin close proximity to the Yankee shell and allows only inchesof clearance for the top half of the vessel.5.3 Cast iron steam heated paper machine dryers are2m6ft in diamete
37、r, or more, and may be 9 m 30 ft long.5.4 Grey cast iron experiences a continuing reduction inelastic modulus as it is stressed to increasing higher levels. It isprudent not to stress grey cast iron material beyond itsoperating stress level.5.5 Flaws to be found are the same as those in any cast and
38、machined product. Attempts have been made to characterizestrength properties of cast irons in compact tension tests. In aTAPPI sponsored laboratory study, two out of three cast ironcompact tension specimens experienced unplanned failures.From that experience it was cautioned that cracks initiated an
39、dgrew faster than expected resulting in brittle fracture before theprocess could be halted. The failure of these two couponsdemonstrated the rate in which cracks can grow in thesematerials and the materials inability to stop a crack once itbegins to grow. In each case, crack advance was extremelyrap
40、id and without warning. (See Note 1.)NOTE 1Alleveto, C., and Williams D., Acoustic Emission Evaluationof Yankee Dryer Shell Material, 1991 TAPPI Engineering ConferenceProceedings, pages 475-480.5.6 Maximum Examination PressureMaximum AllowableWorking Pressure for cast iron vessels is set based on AS
41、ME(Section VIII) pressure calculations based on thickness, radius,and material strength values, and will not exceed 10 bar 160psi and 230C 450F (ASTM A278). When vessels arepressurized, anomalies produce emission at pressures less thannormal fill pressure. Historically, if there is damage in a casti
42、ron pressure boundary, AE activity will begin at load/stresslevels less than 50 % of operating. Defects as small as 3 mm18 in. have been found using AE, during steam pressurizationto operating pressure.5.7 Pressure increments should not exceed 0.35 bar 5 psiper minute. If pressurization medium is to
43、 be steam, the Yankeeshould have been through the warm-up process.5.8 Yankee dryers may receive a subsequent examination, ifnecessary, after the Yankee is rotated to remove any condensatepresent.5.9 Pressurization SchedulePressurization should proceedat rates that allow achieving maximum examination
44、 pressurewithin a 30 minute period. During pressurization, pressureholds are not necessary; however, they may be useful forreasons other than measurement of AE. Pressure hold uponachieving maximum examination pressure may be up to 30minutes.5.10 Excess background noise may distort AE data or rendert
45、he AE measurements useless. Users must be aware of thefollowing common sources of background noise: (measurableflow noise); mechanical contact with the vessel by objects;electromagnetic interference (EMI) from cranes, and radiofrequency inter ference (RFI) from nearby broadcasting facili-ties and fr
46、om other sources; leaks at pipe or hose connections,or rain drops. This practice should not be used if backgroundnoise cannot be eliminated or controlled.5.11 Other Non-destructive test methods may be used toevaluate the significance of AE sources. Magnetic particle,ultrasonic, and radiographic exam
47、inations have been used toestablish circumferential position, depth, and dimensions offlaws that produce AE. Procedures for using other NDTnethods are beyond the scope of this practice.FIG. 1 Yankee Dryer DrumE2598/E2598M 1336. Basis of Application6.1 The following items are subject to contractual a
48、gree-ment between the parties using or referencing this standard.6.2 Personnel Qualification6.2.1 If specified in the contractual agreement, personnelperforming examinations to this standard shall be qualified inaccordance with a nationally or internationally recognizedNDT personnel qualification pr
49、actice 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 practice or standard used and its applicablerevision shall be identified 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 E543. The applicableedition of Practice E543 shall be specified in the contractua
