ASTM D887-82(2003)e1
(Practice)Standard Practices for Sampling Water-Formed Deposits
Standard Practices for Sampling Water-Formed Deposits
SIGNIFICANCE AND USE
The goal of sampling is to obtain for analysis a portion of the whole that is representative. The most critical factors are the selection of sampling areas and number of samples, the method used for sampling, and the maintenance of the integrity of the sample prior to analysis. Analysis of water-formed deposits should give valuable information concerning cycle system chemistry, component corrosion, erosion, the failure mechanism, the need for chemical cleaning, the method of chemical cleaning, localized cycle corrosion, boiler carryover, flow patterns in a turbine, and the rate of radiation build-up. Some sources of water-formed deposits are cycle corrosion products, make-up water contaminants, and condenser cooling water contaminants.
SCOPE
1.1 These practices cover the sampling of water-formed deposits for chemical, physical, biological, or radiological analysis. The practices cover both field and laboratory sampling. It also defines the various types of deposits. The following practices are included: SectionsPractice A-Sampling Water-Formed Deposits From Tubing of Steam Generators and Heat Exchangers8 to 10Practice B-Sampling Water-Formed Deposits From Steam Turbines 11 to 14
1.2 The general procedures of selection and removal of deposits given here can be applied to a variety of surfaces that are subject to water-formed deposits. However, the investigator must resort to his individual experience and judgment in applying these procedures to his specific problem.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. See Section 7, 9.8, 9.8.4.6, and 9.14 for specific hazards statements.
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Designation:D 887–82(Reapproved2003)
Standard Practices for
Sampling Water-Formed Deposits
This standard is issued under the fixed designation D 887; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
e NOTE—Warning notes were editorially moved into the standard text in January 2004.
1. Scope D1193 Specification for Reagent Water
D1245 Practice for Examination of Water-Formed Deposits
1.1 These practices cover the sampling of water-formed
by Chemical Microscopy
deposits for chemical, physical, biological, or radiological
D1293 Test Methods for pH of Water
analysis. The practices cover both field and laboratory sam-
D1428 Test Methods for Sodium and Potassium in Water
pling. It also defines the various types of deposits. The
and Water-Formed Deposits by Flame Photometry
following practices are included:
D2331 Practices for Preparation and Preliminary Testing of
Sections
Water-Formed Deposits
Practice A—Sampling Water-Formed Deposits From Tubing 8to10
of Steam Generators and Heat Exchangers
D2332 Practice for Analysis of Water-Formed Deposits by
Practice B—Sampling Water-Formed Deposits From Steam 11 to 14
Wavelength-Dispersive X-Ray Fluorescence
Turbines
D2579 Test Methods for Total Organic Carbon in Water
1.2 The general procedures of selection and removal of
D3483 Test Methods for Accumulated Deposition in a
deposits given here can be applied to a variety of surfaces that
Steam Generator Tube
aresubjecttowater-formeddeposits.However,theinvestigator
must resort to his individual experience and judgment in 3. Terminology
applying these procedures to his specific problem.
3.1 Definitions of Terms Specific to This Standard:
1.3 This standard does not purport to address all of the
3.1.1 biological deposits—water-formed deposits of organ-
safety concerns, if any, associated with its use. It is the
isms or the products of their life processes.
responsibility of the user of this standard to establish appro-
3.1.1.1 The biological deposits may be composed of micro-
priate safety and health practices and determine the applica-
scopicorganisms,asinslimes,orofmacroscopictypessuchas
bility of regulatory limitations prior to use. See Section 7, 9.8,
barnacles or mussels. Slimes are usually composed of deposits
9.8.4.6, and 9.14 for specific hazards statements.
of a gelatinous or filamentous nature.
3.1.2 corrosion products—a result of chemical or electro-
2. Referenced Documents
chemical reaction between a metal and its environment.
2.1 ASTM Standards:
3.1.2.1 A corrosion deposit resulting from the action of
D512 Test Methods for Chloride Ion in Water
water, such as rust, usually consists of insoluble material
D934 Practices for Identification of Crystalline Compounds
deposited on or near the corroded area; corrosion products
in Water-Formed Deposits by X-Ray Diffraction
may, however, be deposited a considerable distance from the
D993 Test Methods for Sulfate-Reducing Bacteria in Water
point at which the metal is undergoing attack.
and Water-Formed Deposits
3.1.3 scale—a deposit formed from solution directly in
D1129 Terminology Relating to Water
place upon a surface.
3.1.3.1 Scaleisadepositthatusuallywillretainitsphysical
shape when mechanical means are used to remove it from the
These practices are under the jurisdiction ofASTM Committee D19 on Water,
surface on which it is deposited. Scale, which may or may not
and is the direct responsibility of Subcommittee D19.03 on Sampling ofWater and
Water-Formed Deposits, Analysis of Water for Power Generation and Process Use,
adhere to the underlying surface, is usually crystalline and
On-Line Water Analysis, and Surveillance of Water.
dense, frequently laminated, and occasionally columnar in
Current edition approved Oct. 29, 1982. Published March 1983. Originally
structure.
approved in 1946. Last previous edition approved in 1982 as D 887 – 82.
3.1.4 sludge—a water-formed sedimentary deposit.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
3.1.4.1 Thewater-formedsedimentarydepositsmayinclude
Standards volume information, refer to the standard’s Document Summary page on
all suspended solids carried by the water and trace elements
the ASTM website.
3 which were in solution in the water. Sludge usually does not
Withdrawn.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D 887–82 (2003)
coheresufficientlytoretainitsphysicalshapewhenmechanical 6.2 Materials:
means are used to remove it from the surface on which it 6.2.1 The highest purity material available should be used
deposits, but it may be baked in place and be hard and for removing the deposit samples.
adherent. 6.2.2 Filter Paper may contain water leachable contami-
3.1.5 water-formed deposits—any accumulation of in- nants (chloride, fluoride, and sulfur) which can be removed by
soluble material derived from water or formed by the reaction pretreatment prior to sampling.
of water upon surfaces in contact with the water. 6.2.3 Polyester Tape may contain impurities of antimony
3.1.5.1 Deposits formed from or by water in all its phases and cadmium which must be considered during analysis.
may be further classified as scale, sludge, corrosion products,
7. Hazards
or biological deposit. The overall composition of a deposit or
7.1 Warnings:
some part of a deposit may be determined by chemical or
7.1.1 Special safety precautions are necessary in using
spectrographic analysis; the constituents actually present as
acetoneonawipematerialforremovingwater-formeddeposits
chemical substances may be identified by microscope or x-ray
(see 9.8.4.6).
diffraction studies. Organisms may be identified by micro-
7.1.2 Special handling precautions may be required for
scopic or biological methods.
working with water-formed deposits containing radioactive
3.2 Definitions—For definitions of other terms used in these
nuclides (see 9.14).
practices, refer to Definitions D 1129.
7.2 Cautions:
4. Summary of Practices
7.2.1 Extreme care must be taken not to damage the
4.1 These practices describe the procedures to be used for
underlying surface when removing water-formed deposit
sampling water-formed deposits in both the field and labora- samples from equipment in the field (see 9.8).
tory from boiler tubes and turbine components. They give
7.2.2 The selection of samples necessarily depends on the
guidelines on selecting tube and deposit samples for removal experience and judgment of the investigator. The intended use
and specify the procedures for removing, handling, and ship-
of the sample, the accessibility and type of the deposit, and the
ping of samples. problemtobesolvedwillinfluencetheselectionofthesamples
and the sampling method.
5. Significance and Use
7.2.3 The most desirable amount of deposit to be submitted
5.1 The goal of sampling is to obtain for analysis a portion
as a sample is not specific. The amount of deposit should be
of the whole that is representative.The most critical factors are
consistent with the type of analysis to be performed.
the selection of sampling areas and number of samples, the
7.2.4 The samples must be collected, packed, shipped, and
methodusedforsampling,andthemaintenanceoftheintegrity
manipulated prior to analysis in a manner that safeguards
of the sample prior to analysis. Analysis of water-formed
against change in the particular constituents or properties to be
deposits should give valuable information concerning cycle
examined.
system chemistry, component corrosion, erosion, the failure
7.2.5 The selection of sampling areas and number of
mechanism, the need for chemical cleaning, the method of
samples is best guided by a thorough investigation of the
chemical cleaning, localized cycle corrosion, boiler carryover,
problem. Very often the removal of a number of samples will
flow patterns in a turbine, and the rate of radiation build-up.
result in more informative analytical data than would be
Some sources of water-formed deposits are cycle corrosion
obtained from one composite sample representing the entire
products, make-up water contaminants, and condenser cooling
mass of deposit.Atypical example is the sampling of deposits
water contaminants.
from a steam turbine. Conversely, in the case of a tube failure
in a steam generator, a single sample from the affected area
6. Reagents and Materials
may suffice.
6.1 Purity of Reagents—Reagent grade chemicals shall be
7.2.6 Most deposits are sampled at least twice before being
used in all cases. Unless otherwise indicated, it is intended that
submitted to chemical or physical tests. The gross sample is
all reagents shall conform to the specifications of the Commit-
first collected from its point of formation in the field and then
tee onAnalytical Reagents of theAmerican Chemical Society,
this sample is prepared for final examination in the laboratory.
where such specifications are available. Other grades may be
7.2.7 A representative sample is not an absolute prerequi-
used, provided it is first ascertained that the reagent is of
site. The quantity of deposit that can be removed is often
sufficiently high purity to permit its use without lessening the
limited. In such cases, it is better to submit a single mixed
accuracy of analysis.
sample (composite) and to describe how the sample was
6.1.1 Purity of Water— Unless otherwise indicated, refer-
obtained. For radiological analysis all samples should be
ences to water should be understood to mean Type III reagent
checked for activity levels before preparing a composite since
water, Specification D 1193.
wide variations in radioactive content may occur in samples of
similar appearance and chemical composition.
7.2.8 It is good practice for deposits to be taken and
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
analyzed every time a turbine is opened for repairs or inspec-
listed by the American Chemical Society, see Analar Standards for Laboratory
tion. Deposit history can then supplement chemical records of
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
a unit, and deposit chemistry of units with and without
and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,
MD. corrosion and other problems can be compared. Enough
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D 887–82 (2003)
TABLE 1 Selection of Samples
might contain deposits significantly different from the primary
Tube 1 Tube 2 area.Also, one or more tube samples is selected from adjacent
rows or other related areas that might contain deposits signifi-
Principal Adjacent Adjacent
Area Area Tube1or
cantly different from the primary area.
Related
9.1.2 Alternative Selection Procedure 1—Select one or
Tube
more separate tube samples containing the area of failure,
Preferred selection procedure X X X
heaviest deposition, or principle concern (primary area) and
Alternative selection procedure 1 X X
Alternative selection procedure 2 X
include any adjacent or closely related areas of these tube
Alternative selection procedure 3 X
samplesthatmightcontaindepositssignificantlydifferentfrom
Alternative selection procedure 4 X
the primary area. Use this procedure when it is impractical to
remove the samples from adjacent rows or other related areas
or when it is improbable that the information gained by such
information on deposits has been published (1, 2) that a
sampling will justify the additional work involved.
comparison between different types of boilers and different
9.1.3 Alternative Selection Procedure 2—Select one or
water treatments, as well as an assessment of deposit corro-
more separate tube samples containing the area of failure,
siveness, are possible. It has been a general experience that
heaviest deposition, or principle concern (primary area). Use
about 0.2 % of a corrosive impurity, such as chloride, in a
this procedure when only the tube section containing the
deposit, is a division between corrosive and noncorrosive
primary area can be removed or when it is impractical to
deposits.
remove adjacent or closely related areas, or tube samples from
7.2.9 Deposits taken after a turbine is open do not exactly
adjacent rows or other related areas, or when it is improbable
represent chemical composition of deposits in an operating
that the information gained by such sampling will justify the
turbine. Chemical thermodynamic data on steam additives and
additional work involved.
impurities,suchasvaporpressuresofsolutions,ionization,and
9.1.4 Alternative Selection Procedure 3—Select one or
volatility data are needed to reconstruct chemistry of environ-
more tube samples containing an area adjacent or closely
ment during operation.
related to the primary area. Use this procedure only when it is
7.2.10 Typical changes which occur after the hot turbine is
not possible to obtain a tube section containing the primary
shut down and air is admitted are: (1) reactions with oxygen
area.
and carbon dioxide, (2) drying of some deposits and water
9.1.5 Alternative Selection Procedure 4—Select one or
absorption by others, (3) leaching and recrystallization where
moreseparatetubesamplesfromadjacentrowsorotherrelated
moisture is allowed to condense, and ( 4) formation of iron
areas. Use this procedure only when it is not possible to
hydroxide and hematite.
remove a tube section from the primary area, adjacent to the
PRACTICE A—SAMPLING WATER-FORMED
primary area, or closely related to the primary area.
DEPOSITS FROM TUBING OF STEAM
9.2 Taking the Tube Sample—Mark the tube that is to be
GENERATORS AND HEAT EXCHANGERS
removed (sampled) with a crayon.Along arrow can be used to
show: (1) the ligament that is facing into the furnace, and (2)
8. Scope
whichendofthetubeisup.Markthetubebeforeitisremoved.
8.1 This practice covers the sampling of water-formed
The marking should not involve the use of a hammer and die
deposits from tubing of steam generators and heat exchangers.
or paint.
It covers both field and laboratory sampling of water-formed
9.2.1 Whenever possible, remove the tube samples by
deposits. It gives guidelines on selecting tube samples for
sawing. The tube should be dry-cut (no oil). Grinding wheels
removalandspecifiestheprocedureforremovingtubesamples
and cutting torches can be used to obtain tube samples which
from the unit.
cannot be sawed. Grinding wheels and cutting torches can
prod
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