1、Designation: D3483 05 (Reapproved 2009)D3483 14Standard Test Methods forAccumulated Deposition in a Steam Generator Tube1This standard is issued under the fixed designation D3483; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 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. Scope1.1 These test methods cover the determination of the weight per unit area of waterside deposits on heat-transfer
3、 surfaces ofsteam generator tubes. The following test methods are included:SectionsTest Method AMechanical removal by scraper or vibrating tool-removed deposit weight method 7 to 16Test Method BChemical removal by solvent-tube weight loss method 17 to 27Test Method CMechanical removal by glass-bead
4、blasting-tube weight loss method 28 to 371.2 Test Method A is a procedure generally applicable to deposits ranging from 1 to 100 g/ft2. The precision was determinedin the collaborative study over the range of 16 to 76 g/ft2. This methodprocedure allows the discretionary selection of the area onthe t
5、ube to be sampled. The removed deposit allows for further chemical analysis.1.3 Test Method B is a method procedure generally applicable to deposits ranging from 1 to 100 g/ft2. The precision wasdetermined in a collaborative study over the range of 28 to 73 g/ft2. The methodprocedure averages out th
6、e heavier and lighterdeposited areas. The solvent solution produced allows for further chemical analysis.1.4 Test Method C is a procedure generally applicable to deposits ranging from 1 to 100 g/ft2. The precision was determinedin a collaborative study over the range of 17 to 88 g/ft2. The methodpro
7、cedure averages out the heavier and lighter deposited areas.The removed deposit does not allow for further chemical analysis.1.5 These test methods have been generally evaluated on the types of waterside deposits generally found on heat-transfersurfaces of steam generator tubes. It is the users resp
8、onsibility to ensure the validity of these test methods for other types ofdeposits or high temperature scale.1.6 These methods are sometimes used for accumulated deposition in rifled steam generator tubes. Experience has shown thatthere is a significant difference in the deposition in the grooves an
9、d on the lands on some rifled steam generator tubes. The grooveshave been shown to hold more deposit. Test Method B and Test Method C will average out this difference. In MethodAthe choiceexists, either to choose to remove the deposition from the groove if it is visually determined to be more heavil
10、y deposited, or toremove equally over the grooves and lands. It is important that it be understood what choices were made and that the report reflectthe choices made when using Test Method A on rifled steam generator tubes.1.7 There are some steam generator tubes where it is apparent that half of th
11、e tube is exposed to the flame from the externalappearance, this side is typically called the fireside or hot side. The other half of the tube is not exposed to the flame from theexternal appearance is typically called the casing side or cold side. These test methods also require that the tube be sp
12、lit in half,so the tube is generally split along these lines. On these tubes it is generally found that more internal deposition exists on thefireside or hot side. Some users of these methods will determine the deposition only on side where it appears visually that moredeposition exists. Some users
13、will determine the deposition on both sides and report the results separately and some will averagethe two results. It is important that the user of the data be aware of the choices made and that the report of the results be specific.1.8 The values stated in either SI or inch-pound units are to be r
14、egarded as the standard. The values given in parentheses arefor information only.1.9 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of theuser of this standard to establish appropriate safety and health practices and determine
15、 the applicability of regulatory limitationsprior to use.1 These test methods are under the jurisdiction of ASTM Committee D19 on Water and are the direct responsibility of Subcommittee D19.03 on Sampling Water andWater-Formed Deposits, Analysis of Water for Power Generation and Process Use, On-Line
16、 Water Analysis, and Surveillance of Water.Current edition approved May 1, 2009Jan. 1, 2014. Published June 2009January 2014. Originally approved in 1975. Last previous edition approved in 20052009 asD348383 (2005). DOI: 10.1520/D3483-05R09. 83 (2009). DOI: 10.1520/D3483-14.This document is not an A
17、STM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In
18、all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12. Referenced Documents2.1 ASTM Standards:2D887 Practices for Sampling Wa
19、ter-Formed DepositsD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on WaterG1 Practice for Preparing, Cleaning, and Evaluating Corrosion Test Specimens2.2 Other Documents:NACE S
20、tandard TM0199-99, Item No. 21236, Standard Test Method for Measuring Deposit Mass Loading (“Deposit WeightDensity”) Values for Boiler Tubes by the Glass-Bead-Blasting TechniqueNACE International Publication 7H100, Item No. 24206,24206 Evaluation of Boiler Tube Deposit Mass Loading (DepositWeight De
21、nsity) Methodology3. Terminology3.1 DefinitionsFor definitions of terms used in thisthese test method,methods, refer to Terminology D1129.4. Significance and Use4.1 The weight per unit area measurement is an indication of the relative cleanliness or dirtiness of the boiler. It is used todetermine th
22、e effectiveness of the boiler chemical treatment program and to determine the need for chemically cleaning the boilersystems.Allowing the internal deposition to accumulate unchecked will likely lead to boiler tube failures by mechanisms of underdeposit corrosion and tube metal overheating.5. Reagent
23、s and Materials5.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that allregents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society.3 Othergrades may be used, provided it is f
24、irst ascertained that the reagent is of sufficiently high purity to permit its use without lesseningthe accuracy of the determination.5.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean reagent water conforming toSpecification D1193, Type 4.6. Sampling6.1 S
25、elect a tube section likely to have the heaviest deposit. Experience has shown that deposit accumulation is usually heavieston tube surfaces that receive the highest heat transfer. Representative areas of especially high heat transfer are:6.1.1 The center of the division wall at the top burner eleva
26、tion in a boiler with a division panel wall where firing occurs onopposite sides.6.1.2 The side wall near the top burner elevation, at about 13 furnace depth from the burner wall, in a boiler without a divisionwall.6.1.3 Other high heat transfer areas in a more complex boiler design as indicated by
27、the boiler manufacturer.6.2 Areas in the boiler where impaired circulation is suspected may also be sampled.6.3 The optimal tube removal method is by dry cutting. No oil or water is to be used in the tube cutting process. The lengthof sample should be 24 to 36 in., but allow an extra 12 in. on each
28、end if the sample is cut out by torch.6.4 After the tube sample is removed, provide suitable identification, showing location in the boiler, orientation of tube, and thehot and cold sides of the tube in accordance with Practices D887.TEST METHOD AMECHANICAL REMOVAL BY SCRAPER OR VIBRATING TOOL7. Sco
29、pe7.1 This test method covers the determination of accumulated deposition in a steam generator tube by the mechanical removalof the deposit by scraper or vibrating tool, the collection and weighing of the dry deposit. This collected deposit is then availablefor further chemical analysis, if desired.
30、 The method also allows for discretionary removal of the deposit from the tube in areasof the most interest.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the stand
31、ards Document Summary page on the ASTM website.3 Reagent Chemicals, American Chemical Society Specifications, , American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., P
32、oole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville, MD.D3483 1428. Summary of Test Method8.1 The tube is split and the area to be tested is determined after examination; usually the area judged to be most heavilydeposi
33、ted. The deposits are removed mechanically by scraping or vibrating from a measured area. The collected deposit is weighedand the result is usually reported as grams of deposit per square foot of boiler tube surface.9. Interferences9.1 There are no interferences, only errors in collecting the deposi
34、t, 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 portion of the boiler tube.10.2 Tube Cutter.10.3 Tube End Sealers, to protect the sample until the determination can be mad
35、e.10.4 Milling Machine or Band Saw, to separate the tube into halves by longitudinal sectioning (dry cut).10.5 Magnet, to remove cutting metal chips from the deposited material.10.6 Scraping Tool, for removal of less adherent deposits. Scraper material of construction needs to be of sufficient hardn
36、essas not to contaminate the deposit sample.10.7 Vise, sometimes is used to crimp tube to remove brittle deposits.10.8 Vibrating Tool, to remove more adherent deposits. A small head should be available for use within pits.10.9 Oven, for drying deposits.10.10 Analytical Balance, for weighing deposits
37、.11. Procedure11.1 Split the tube sample taken in Section 66 in halves longitudinally, separating the hot side from the cold side if thedistinction is apparent from the external surface or from labeling. Be careful to disturb the internal deposit as little as possible.Carefully remove all cutting fr
38、agments from the deposit with the magnet.11.2 Examine and photograph the internal surfaces, if desired. Determine the area to be tested and mark off the boundaries. Thiswill usually be the area of heaviest deposit and will be on the hot side section of the tube. A similar area can be marked off andt
39、ested on the cold side section for comparison, if desired.11.3 Carefully, scrape the surface to dislodge and individually collect the more easily removable deposits from the selected area.Complete the deposit removal by brushing or applying an electric vibrating tool, or both. Dry the removed materi
40、al in an oven at105C for 1 hour if it appears to be hydrated. It is optional to grind the removed deposit sufficiently to pass through a No. 325(45-m) stainless steel sieve and weigh the screened portion. Record the weight in milligrams.11.4 Determine the area from which the deposit was removed, mea
41、suring each dimension to the nearest 1 mm. If the area hasa regular shape, direct measurement can be used. If the area has an irregular shape, one technique used to determine the area isto trim paper to the pattern of the actual surface that had deposit removed. Then determine the area by comparing
42、the weight ofthe irregular paper pattern to the weight of a paper of known area.12. Calculation12.1 Determine the weight of accumulated deposits per unit area, by dividing the removed deposit weight by the measured area.13. Report13.1 The results are usually reported as g/ft2.14. Precision and Bias1
43、4.1 Practice D2777 is not applicable to this Standard Test Method test method because a known and repeatable standardreference deposit contained within a steam generator tube cannot be produced.14.2 Factors that produce errors in mass loss measurement include improper balance calibration, loss of re
44、moved depositionprior to weighing, incomplete deposition removal, and removal of base metal. Generally, modern analytical balances if calibratedand used correctly are not considered to be a significant source of error. The other factors are considered more significant.14.3 The determination of the s
45、ample area is likely the least precise step with this method, particularly for riffled tubes.14.4 This method was tested by five laboratories. These collaborative test data were obtained on sections of boiler tube samplesfrom two specific boilers. For other boiler tube samples, these data may not ap
46、ply.D3483 14314.4.1 PrecisionAn example of the precision obtained on these specific boiler tubes is shown in Fig. 1.14.4.2 BiasBias data could not be determined because of the lack of a boiler tube containing a known and consistent deposit.14.5 Data for this estimated procedure variance is from NACE
47、 International Publication 7H100, Item No. 24206, “Evaluationof Boiler Tube Deposit Mass Loading (Deposit Weight Density) Methodology.”24206.15. Quality Control (QC)15.1 In order to be certain that analytical values obtained using this test method are valid and accurate within the confidencelimits o
48、f the test, the following QC procedures must be followed when running the test:15.2 A method has been shown to determine the optimum length of time or other variable factors concerning the cleaningprocedure, which indicates the optimum point where deposition has been removed but base metal has not b
49、een removed, as shownin ASTM Standard Practice G1 Standard Practices for Preparing, Cleaning, and Evaluating Corrosion Test Specimens. .15.3 Calibration and Calibration Verification:15.3.1 Analytical BalanceFollow the balance manufacturers recommendations for calibration procedure and frequency.Check the balance with a class S weight in the range of the expected deposit sample weight on the day of use. Recalibrate, asneeded.16. Keywords16.1 boiler; deposit; deposition; rifled; steam generator tubeFIG. 1 Interlaboratory Precision of Accumulated Deposition in a Ste
