ASTM D933-20

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Designation: D933 − 84 (Reapproved 2012) D933 − 20
Standard Practice for
Reporting Results of Examination and Analysis of Water-
Formed Deposits
This standard is issued under the fixed designation D933; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This practice covers the manner in which the results of examination and analysis for inorganic constituents of deposits
formed from waters on systems using water as a heat transfer media or water formed deposits from any other purpose and how
they are to be reported.
1.2 While various practices of reporting the analysis of water-formed deposits are in use, this practice is intended as a rational
and comprehensive practice for general application. For use in specific industries or individual cases, molecular combinations may
be useful and desirable.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D887 Practices for Sampling Water-Formed Deposits
D1129 Terminology Relating to Water
This practice is under the jurisdiction of ASTM Committee D19 on Water and is the direct responsibility of Subcommittee D19.03 on Sampling Water and Water-Formed
Deposits, Analysis of Water for Power Generation and Process Use, On-Line Water Analysis, and Surveillance of Water.
Current edition approved Jan. 1, 2012May 1, 2020. Published January 2012June 2020. Originally approved in 1947. Last previous edition approved in 20072012 as
D933 – 84 (2012). (2007). DOI: 10.1520/D0933-84R12.10.1520/D0933-20.
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 Standards
volume information, refer to the standard’sstandard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D933 − 20
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this standard, refer to Terminology D1129.
3.2 Definitions of Terms Specific to This Standard:—For
3.2.1 acid solubility in 1 to 1 acid, n—concentration of a deposit or solid, in grams per litre that will go into solution in an acidic
solvent divided by initial weight of the sample. Thus, results are reported as a percentage soluble or dissolved.
3.2.1.1 Discussion—
For water borne deposits, these analyses are more qualitative or estimates of solubility of the deposit or solid (1 or more grams)
in a solution of 1 to 1 acid. The acids most commonly used are either 1 to 1 hydrochloric acid (HCl (6 normal)) and nitric acid
(HNO (7.9 normal)) as the acidic solvent because they will normally dissolve most water formed deposits or scales. The sample
can be weighed and placed in a soxhlet extractor with reflux and reweighed for calculation in % solubility. Note that inorganic
carbonates will rapidly evolve and effervesce upon addition to the acid. Other inorganics will dissolve in the acid upon heat.
3.2.2 loss on ignition (LOI), n—the percent loss in weight of a material on being calcined at a temperature selected, for a time
long enough, to achieve constant weight, expressed as a percent of the initial weight of the dry material (without free moisture).
3.2.2.1 Discussion—
LOI’s for deposits are normally run at 105°C for determination of moisture content. 450°C to 500°C for determination of organics
in the sample. 900°C to 1000°C for determination of inorganic carbonates. The final calculation is for the remaining material,
which is the ash content, which is the measure of the remaining inorganics in the sample. The sample can be weighed and stepped
thru the process and reweighed after each temperature for calculation in % loss. definitions
3.2.3 non-polar solvent extractable solubility, n—concentration of a deposit or solid, in grams per litre that will go into solution
in a non-polar solvent divided by initial weight of the sample. Thus, results are reported as a percentage soluble or dissolved.
3.2.3.1 Discussion—
For water borne deposits, these analyses are more qualitative or estimates of solubility of the deposit or solid (1 or more grams)
in a non-polar solvent. Ether, hexane and other solvents that will extract organic compounds from the deposit or solids can be used.
Oils and greases and other organics can come from process contaminants and can bind the deposit together. The sample can be
weighed and placed in a soxhlet extractor with reflux and reweighed for calculation in % solubility. of terms used in this practice
reference should be made to Terminology D1129.
4. Significance and Use
4.1 The results are used to characterize the scale formed and used and water formed deposits formed in systems using water
as a heat transfer fluid or deposits formed that has resulted from water being transported, stored or used for any other purpose. It
is also used to evaluate the quality of water used in the unit. Characterizing the scalesystem where the deposit has been found.
Characterizing the scale/deposit will assist in the design of the water treatment processprotocols to avoid further scale buildup. or
deposit buildups which can cause increased energy consumption or damage to the system due to corrosion or microbiological
growth. The use of modern up-to-date chemical detection unitssystems will increase the usefulness of the practice.
5. History of Sample
5.1 Information regarding the source source, background and history of the samplesystem shall be included in the report of the
analysis. (Pictures are helpful to identify where the deposit was found and the conditions in the system.) This information should
be thatas specified in Practices D887, as follows:
5.1.1 Name of individual or company supplying sample,sample to the laboratory.
5.1.2 Geographic origin of sample,sample (this helps in determining make-up water quality).
5.1.3 Date and time of sampling,sampling.
5.1.4 Number of sample,sample/s.
5.1.5 Name and other designation of equipment from which sample was removed,or samples were removed.
5.1.6 Precise location from which sample was removed (for example, exactly what turbine blade),blade, exactly what tube in
a boiler or heat exchanger) or where in the heat exchanger or cooling tower it was found (for example, 6 o’clock position in a
horizontal run of pipe right after feedwater tank). (Pictures again are helpful in this identification.)
D933 − 20
5.1.7 History of System—Operational characteristics, when was the last time the system was inspected, and how long a period
it took for the deposit to form.
5.1.8 Direction of flow in the areas where the deposit was found and surface temperature of that area, if known, of heat transfer
equipment or zone where deposit was found.
5.1.9 Appearance and extent of deposit prior to removal,removal. (Pictures again are helpful.)
5.1.10 Report the metallurgies involved with the system along with the metallurgy of area where the deposit was found. This
is especially needed when the substrate from which the deposit was removed could influence the formation of the deposit or scale.
5.1.11 Type of deposit—whether deposit whether scale, sludge, biological deposit, or corrosion productby-products as defined
in Practices D887,.
5.1.12 Exact method that was used in removing the sample and notes concerning any contamination that might have occurred
during the process,process of removal by the tool used to remove the deposit (for example, if deposit removed by a wire brush,
scraper, scalpel or pick, metallurgy of wire brush, scraper, scalpel or pick utilized should be recorded). Also, metallurgy of pipe
or wall of pipe or surface where deposit is removed from should be recorded since the tools used and the metallurgy of the surface
can lead to contaminants in the deposit (for example, nickel plated surface where deposit is removed from by stainless steel scraper
– if nickel, molybdenum, or chromium is found in sample deposit, it could be from the removal action).
5.1.13 Operating temperature and pressure of liquid or vapor in the equipment that contained the deposit,deposit (water side)
and also if in a heat exchanger or boiler also record the surface temperature of the liquid or vapor that the water comes indirect
contact with.
5.1.14 Type of and chemistry of the water treatment applied to the water that formed the deposit or to the water that furnished
steam to the affected zone,zone.
5.1.15 Make-up water analysis of water used to maintain water level in the system where deposit was formed and history of
that water. (Please identify if any changes occurred in the make-up water since the last time the system was inspected, for example
if system water was being maintained by municipal water switched to recycle water source.)
5.1.16 Water analysis of system water and any changes that have occurred since the last time the system was inspected (for
example, water treatment company changed inhibitors utilized).
NOTE 1—If these water analyses are not available, they should be done as part of the deposit analyses.
5.1.17 An account of discrepancies in operating conditionconditions that may have contributed to deposition (for example,
water starving),loss or starving, more or less load characteristics, water main break that caused poor water quality, loss of chemical
feed, blowdown malfunctioned, etc.).
5.1.18 Results of field tests made on the sample or related equipment, andequipment.
5.1.19 Any other pertinent information about the system that may or may not seem relevant including other equipment that
could have impacted the water system (for example, exhaust fans near a cooling tower, sugar heat exchanger that has steam on
one side and sugar on the other, etc.).
NOTE 2—Either can cause contamination of the water-based system.
5.1.20 Signature of sampler.
6. Physical Characteristics
6.1 The report shall include a description of the physical characteristics of the sample, including any peculiarities that may be
pertinent in its further examination. (For example, smell or odor, foaming when acid was added, etc.).
6.2 Characteristics such as the following may be recorded: color, form, (scaly,form (scale, slimy, drusy, etc.), texture (oily,
smooth, friable, gritty, etc.), hardness, magnetic properties (as determined by test with magnet), and structure (amorphous,
crystalline, columnar crystals).
TABLE 1 Proximate Analysis
Solubility in Solvents
A
Acid – soluble matter (soluble in 1 to 1 acid ) %
Ether (solvent) - extractable matter (oil) %
Water soluble matter %
Loss on Ignition
Moisture (at 105°C ) %
Loss on ignition at 450°C (organics) %
Loss on ignition at 900°C (inorganic carbonates) %
Ash % (900°C) (inorganics) %
A
Graphite or other forms of carbon shall be reported as C.One volume of
deionized water to one volume of concentrated acid (see Discussion to term acid
solubility in 1 to 1 acid,3.2.1).
D933 − 20
7. Completeness and Accuracy of Analysis
7.1 Reporting of the general physical analysis of the deposit shall first be reported. Table 1 lists the most common Proximate
Analysis to be reported but others can be reported.
7.2 The determinations to be reported in a complete analysis shall be those listed in Table 12. For many practical purposes, a
less complete analysis will suffice. In other instances, the location or nature of the deposit or a knowledge of the composition of
the equipment affected will suggest the need for determinations in addition to those listed.
NOTE 3—Other oxides may be present such as barium, strontium, and other metallurgical compounds. These should be tested for if knowledge in the
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