ASTM D3483-2005 Standard Test Methods for Accumulated Deposition in a Steam Generator Tube《蒸汽发生器管中累积沉积物的标准试验方法》.pdf

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1、Designation: D 3483 05Standard Test Methods forAccumulated Deposition in a Steam Generator Tube1This standard is issued under the fixed designation D 3483; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.

2、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 These test methods cover the determination of theweight per unit area of waterside deposits on heat-transfersurfaces of steam genera

3、tor tubes. The following test methodsare included:SectionsTest Method AMechanical removal by scraper or vibratingtool-removed deposit weight method7to16Test Method BChemical removal by solvent-tube weight lossmethod17 to 27Test Method CMechanical removal by glass-bead blasting-tube weight loss metho

4、d28 to 371.2 Test Method A is a procedure applicable to depositsranging from 16 to 76 g/ft2. This method allows the discre-tionary selection of the area on the tube to be sampled. Theremoved deposit allows for further chemical analysis.1.3 Test Method B is a method applicable to depositsranging from

5、 28 to 73 g/ft2. The method averages out theheavier and lighter deposited areas. The solvent solutionproduced allows for further chemical analysis.1.4 Test Method C is a procedure applicable to depositsranging from 17 to 88 g/ft2. The method averages out theheavier and lighter deposited areas. The r

6、emoved deposit doesnot allow for further chemical analysis.1.5 These test methods have been generally evaluated on thetypes of waterside deposits generally found on heat-transfersurfaces of steam generator tubes. It is the users responsibilityto ensure the validity of these test methods for other ty

7、pes ofdeposits or high temperature scale.1.6 These methods are sometimes used for accumulateddeposition in rifled steam generator tubes. Experience hasshown that there is a significant difference in the deposition inthe grooves and on the lands on some rifled steam generatortubes. The grooves have b

8、een shown to hold more deposit. TestMethod B and Test Method C will average out this difference.In Method A the choice exists, either to choose to remove thedeposition from the groove if it is visually determined to bemore heavily deposited, or to remove equally over the groovesand lands. It is impo

9、rtant that it be understood what choiceswere made and that the report reflect the choices made whenusing Test Method A on rifled steam generator tubes.1.7 There are some steam generator tubes where it isapparent that half of the tube is exposed to the flame from theexternal appearance, this side is

10、typically called the fireside orhot side. The other half of the tube is not exposed to the flamefrom the external appearance is typically called the casing sideor cold side. These test methods also require that the tube besplit in half, so the tube is generally split along these lines. Onthese tubes

11、 it is generally found that more internal depositionexists on the fireside or hot side. Some users of these methodswill determine the deposition only on side where it appearsvisually that more deposition exists. Some users will determinethe deposition on both sides and report the results separatelya

12、nd some will average the two results. It is important that theuser of the data be aware of the choices made and that thereport of the results be specific.1.8 The values stated in either SI or inch-pound units are tobe regarded as the standard. The values given in parenthesesare for information only.

13、1.9 This standard does not purport to address the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1

14、 ASTM Standards:2D 887 Practices for Sampling Water-Formed DepositsD 1129 Terminology Relating to WaterD 1193 Specification for Reagent WaterG1 Practice for Preparing, Cleaning, and Evaluating Cor-rosion Test Specimens2.2 Other Documents:NACE Standard TM0199-99, Item No. 21236, StandardTest Method f

15、or Measuring Deposit Mass Loading (“De-posit Weight Density”) Values for Boiler Tubes by theGlass-Bead-Blasting TechniqueNACE International Publication 7H100, Item No.1These test methods are under the jurisdiction of ASTM Committee D19 onWater and are the direct responsibility of Subcommittee D19.03

16、 on Sampling ofWater and Water-Formed Deposits, Analysis of Water for Power Generation andProcess Use, On-Line Water Analysis, and Surveillance of Water.Current edition approved June 1, 2005. Published July 2005. Originally approvedin 1975. Last previous edition approved in 2005 as D 348383 (2005).2

17、For 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 Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C

18、700, West Conshohocken, PA 19428-2959, United States.24206, Evaluation of Boiler Tube Deposit Mass Loading(Deposit Weight Density) Methodology3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology D 1129.4. Significance and Use4.1 The weight per unit area

19、 measurement is an indicationof the relative cleanliness or dirtiness of the boiler. It is used todetermine the effectiveness of the boiler chemical treatmentprogram and to determine the need for chemically cleaning theboiler systems. Allowing the internal deposition to accumulateunchecked will like

20、ly lead to boiler tube failures by mecha-nisms of under deposit corrosion and tube metal overheating.5. Reagents and Materials5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall regents shall conform to the specifications of the

21、 Committeeon Analytical Reagents of the American Chemical Society.3Other grades may be used, provided it is first ascertained thatthe reagent is of sufficiently high purity to permit its usewithout lessening the accuracy of the determination.5.2 Purity of WaterUnless otherwise indicated, referencest

22、o water shall be understood to mean reagent water conformingto Specification D 1193, Type 4.6. Sampling6.1 Select a tube section likely to have the heaviest deposit.Experience has shown that deposit accumulation is usuallyheaviest on tube surfaces that receive the highest heat transfer.Representativ

23、e areas of especially high heat transfer are:6.1.1 The center of the division wall at the top burnerelevation in a boiler with a division panel wall where firingoccurs on opposite sides.6.1.2 The side wall near the top burner elevation, at about13furnace depth from the burner wall, in a boiler witho

24、ut adivision wall.6.1.3 Other high heat transfer areas in a more complexboiler design as indicated by the boiler manufacturer.6.2 Areas in the boiler where impaired circulation is sus-pected may also be sampled.6.3 The optimal tube removal method is by dry cutting. Nooil or water is to be used in th

25、e tube cutting process. The lengthof sample should be 24 to 36 in., but allow an extra 12 in. oneach end if the sample is cut out by torch.6.4 After the tube sample is removed, provide suitableidentification, showing location in the boiler, orientation oftube, and the hot and cold sides of the tube

26、in accordance withPractices D 887.TEST METHOD AMECHANICAL REMOVAL BYSCRAPER OR VIBRATING TOOL7. Scope7.1 This test method covers the determination of accumu-lated deposition in a steam generator tube by the mechanicalremoval of the deposit by scraper or vibrating tool, thecollection and weighing of

27、the dry deposit. This collecteddeposit is then available for further chemical analysis, ifdesired. The method also allows for discretionary removal ofthe deposit from the tube in areas of the most interest.8. Summary of Test Method8.1 The tube is split and the area to be tested is determinedafter ex

28、amination; usually the area judged to be most heavilydeposited. The deposits are removed mechanically by scrapingor vibrating from a measured area. The collected deposit isweighed and the result is usually reported as grams of depositper square foot of boiler tube surface.9. Interferences9.1 There a

29、re no interferences, only errors in collecting thedeposit, removing sufficient deposit, not removing base metal,determination of the sample weight and the sampled area.10. Apparatus10.1 Cutting Tool or Torch, for removing a suitable portionof the boiler tube.10.2 Tube Cutter.10.3 Tube End Sealers, t

30、o protect the sample until thedetermination can be made.10.4 Milling Machine or Band Saw, to separate the tube intohalves by longitudinal sectioning (dry cut).10.5 Magnet, to remove cutting metal chips from thedeposited material.10.6 Scraping Tool, for removal of less adherent deposits.Scraper mater

31、ial of construction needs to be of sufficienthardness as not to contaminate the deposit sample.10.7 Vise, sometimes is used to crimp tube to remove brittledeposits.10.8 Vibrating Tool, to remove more adherent deposits. Asmall head should be available for use within pits.10.9 Oven, for drying deposit

32、s.10.10 Analytical Balance, for weighing deposits.11. Procedure11.1 Split the tube sample taken in Section 6 in halveslongitudinally, separating the hot side from the cold side if thedistinction is apparent from the external surface or fromlabeling. Be careful to disturb the internal deposit as litt

33、le aspossible. Carefully remove all cutting fragments from thedeposit with the magnet.11.2 Examine and photograph the internal surfaces, if de-sired. Determine the area to be tested and mark off theboundaries. This will usually be the area of heaviest depositand will be on the hot side section of th

34、e tube. A similar areacan be marked off and tested on the cold side section forcomparison, if desired.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Ana

35、lar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.D348305211.3 Carefully, scrape the surface to dislodge and individu-ally collect the more easily removable deposit

36、s from theselected area. Complete the deposit removal by brushing orapplying an electric vibrating tool, or both. Dry the removedmaterial in an oven at 105C for 1 hour if it appears to behydrated. It is optional to grind the removed deposit suffi-ciently to pass through a No. 325 (45-m) stainless st

37、eel sieveand weigh the screened portion. Record the weight in milli-grams.11.4 Determine the area from which the deposit was re-moved, measuring each dimension to the nearest 1 mm. If thearea has a regular shape, direct measurement can be used. If thearea has an irregular shape, one technique used t

38、o determinethe area is to trim paper to the pattern of the actual surface thathad deposit removed. Then determine the area by comparingthe weight of the irregular paper pattern to the weight of apaper of known area.12. Calculation12.1 Determine the weight of accumulated deposits per unitarea, by div

39、iding the removed deposit weight by the measuredarea.13. Report13.1 The results are usually reported as g/ft2.14. Precision and Bias14.1 Practice D 2777 is not applicable to this Standard TestMethod because a known and repeatable standard referencedeposit contained within a steam generator tube cann

40、ot beproduced.14.2 Factors that produce errors in mass loss measurementinclude improper balance calibration, loss of removed deposi-tion prior to weighing, incomplete deposition removal, andremoval of base metal. Generally, modern analytical balancesif calibrated and used correctly are not considere

41、d to be asignificant source of error. The other factors are consideredmore significant.14.3 The determination of the sample area is likely the leastprecise step with this method, particularly for riffled tubes.14.4 This method was tested by five laboratories. Thesecollaborative test data were obtain

42、ed on sections of boiler tubesamples from two specific boilers. For other boiler tubesamples, these data may not apply.14.4.1 PrecisionAn example of the precision obtained onthese specific boiler tubes is shown in Fig. 1.14.4.2 BiasBias data could not be determined because ofthe lack of a boiler tub

43、e containing a known and consistentdeposit.FIG. 1 Interlaboratory Precision of Accumulated Deposition in a Steam Generator TubeD348305314.5 Data for this estimated procedure variance is fromNACE International Publication 7H100, Item No. 24206,“Evaluation of Boiler Tube Deposit Mass Loading (DepositW

44、eight Density) Methodology.”15. Quality Control (QC)15.1 In order to be certain that analytical values obtainedusing this test method are valid and accurate within theconfidence limits of the test, the following QC procedures mustbe followed when running the test:15.2 A method has been shown to dete

45、rmine the optimumlength of time or other variable factors concerning the cleaningprocedure, which indicates the optimum point where deposi-tion has been removed but base metal has not been removed, asshown in ASTM Standard G1Standard Practices for Prepar-ing, Cleaning, and Evaluating Corrosion Test

46、Specimens.15.3 Calibration and Calibration Verification:15.3.1 Analytical BalanceFollow the balance manufactur-ers recommendations for calibration procedure and frequency.Check the balance with a class S weight in the range of theexpected deposit sample weight on the day of use. Recalibrate,as neede

47、d.16. Keywords16.1 boiler; deposit; deposition; rifled; steam generator tubeTEST METHOD BCHEMICAL REMOVAL BYSOLVENT17. Scope17.1 This test method covers the determination of accumu-lated deposition in a steam generator tube by chemical removalof the deposit and measuring the weight change in the dep

48、osit.This solvent containing the deposit is then available for furtherchemical analysis, if desired. The method does not allow fordiscretionary removal of the deposit from the tube in areas ofthe most interest.18. Summary of Test Method18.1 The deposit that has accumulated in the selected boilertube

49、 specimen is determined by measuring the weight loss ofthe tube sample after deposit removal with inhibited hydro-chloric acid. In the event copper plates out on the tube sampleduring the cleaning operation, an ammonium persulfate solu-tion is used to remove the copper prior to final weighing. Therequired machining of the outside surface of the selected tubesample to a wall thickness of approximately 1 mm (116 in.) willincrease the sensitivity of the measurement and eliminateinterference from external deposits.19. Interferences19.1 Loss of base metal by the solvent, i