ASTM D8073-22

Standard Test Method for Determination of Water Separation Characteristics of Aviation Turbine Fuel by Small Scale Water Separation Instrument

SIGNIFICANCE AND USE
5.1 This test method provides an indication of the presence of surfactants in aviation fuel. Like Test Methods D2550, D3602, D3948, and D7224, this test method can detect carryover traces of refinery treating residues in fuel as produced. In addition, these test methods can detect surface active substances added to or picked up by the fuel during handling from point of production to point of use. Certain additives can affect the WSI. Some of these substances affect the ability of filter separators to separate free water from the fuel.  
5.2 The small scale water separation tester has a measurement range from 0.0 WSI to 100.0 WSI.
Note 1: WSI values greater than 100.0 WSI can be caused by a reduction in the light transmittance (see A1.1.5) of the test specimen due to material that was removed during the testing process.  
5.3 This test method was developed so refiners, fuel terminal operators, pipelines, and independent testing laboratory personnel can rapidly and precisely measure for the presence of surfactants, with a minimum of training, in a wide range of locations.
SCOPE
1.1 This test method covers a procedure to rate the ability of aviation turbine fuels to release entrained and emulsified water when passed through a water-coalescing filter.  
1.2 Results are expressed as a Water Separation Index (WSI).  
1.3 The values stated in SI units are to be regarded as standard.  
1.3.1 Exception—Units in WSI are included.  
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, health, and environmental 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.

General Information

• Status: Published
• Publication Date: 31-Mar-2022
• ICS: 75.160.20 - Liquid fuels
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.J0.05 - Fuel Cleanliness

Relations

• Refers: ASTM D1655-24 - Standard Specification for Aviation Turbine Fuels
• Effective Date: 15-Mar-2024
• Refers: ASTM D6300-24 - Standard Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Mar-2024
• Refers: ASTM D6300-23a - Standard Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Dec-2023
• Refers: ASTM D1655-23a - Standard Specification for Aviation Turbine Fuels
• Effective Date: 01-Oct-2023
• Refers: ASTM D6300-19a - Standard Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products and Lubricants
• Effective Date: 01-Dec-2019
• Refers: ASTM D1655-18 - Standard Specification for Aviation Turbine Fuels
• Effective Date: 01-Jan-2018
• Refers: ASTM D1655-17a - Standard Specification for Aviation Turbine Fuels
• Effective Date: 01-Dec-2017
• Refers: ASTM D1655-16c - Standard Specification for Aviation Turbine Fuels
• Effective Date: 01-Dec-2016
• Refers: ASTM D1655-16b - Standard Specification for Aviation Turbine Fuels
• Effective Date: 01-Sep-2016
• Refers: ASTM D1655-16 - Standard Specification for Aviation Turbine Fuels
• Effective Date: 01-Jun-2016
• Refers: ASTM D6300-16 - Standard Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products and Lubricants
• Effective Date: 01-Apr-2016
• Refers: ASTM D4306-15 - Standard Practice for Aviation Fuel Sample Containers for Tests Affected by Trace Contamination
• Effective Date: 01-Oct-2015
• Refers: ASTM D1655-15d - Standard Specification for Aviation Turbine Fuels
• Effective Date: 01-Oct-2015
• Refers: ASTM D1655-15b - Standard Specification for Aviation Turbine Fuels
• Effective Date: 15-Jul-2015
• Refers: ASTM D6300-15 - Standard Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products and Lubricants
• Effective Date: 01-Jun-2015

Overview

ASTM D8073-22 is the Standard Test Method for Determination of Water Separation Characteristics of Aviation Turbine Fuel by Small Scale Water Separation Instrument. Published by ASTM International, this standard defines a controlled method for evaluating how easily aviation turbine fuel can separate from water when passed through a water-coalescing filter. The procedure measures the influence of surfactants and other surface-active substances, which may impact the performance of fuel separation equipment and overall fuel cleanliness.

The test yields a Water Separation Index (WSI), indicating the capacity of aviation fuels to release entrained and emulsified water. Maintaining optimal water separability is critical in aviation fuels to ensure operational safety, fuel quality, and the reliable performance of aircraft engines.

Key Topics

• Purpose: Measures the impact of surfactants and additives on water separation efficiency in aviation turbine fuels.
• Test Range: WSI values range from 0.0 to 100.0, where higher values indicate better water separability.
• Detection Capabilities: Enables detection of refinery residues, processing carryover, or contaminants absorbed during handling and transportation.
• Test Method: Utilizes a specialized, small-scale water separation instrument, including a sonicator, dye detector, and coalescing filter, to simulate the water-removal process.
• Practicality: Designed for rapid, precise, and relatively simple operation, making it suitable for use at refineries, fuel terminals, pipelines, and in independent laboratories.
• Sample Handling: Emphasizes the importance of correct sample collection without pre-filtering, to avoid removing the very surfactants the test is designed to detect.

Applications

ASTM D8073-22 is essential for a range of stakeholders in the aviation fuel supply chain:

• Fuel Producers and Refiners: Assure the cleanliness and performance of aviation turbine fuel prior to distribution.
• Terminal Operators and Pipelines: Monitor fuel quality during storage and transfer to prevent water contamination, which could lead to engine problems or safety issues.
• Independent Testing Laboratories: Use the test to provide consistent, traceable quality assurance for aviation turbine fuels.
• Quality Assurance and Regulatory Compliance: Helps organizations meet industry and regulatory requirements for aviation fuel cleanliness by monitoring the presence of surfactants and potential contaminants.
• Operational Readiness: Rapid diagnosis of potential issues related to water separation in aviation fuels, supporting preventative maintenance and incident avoidance in aviation operations.

Related Standards

Professionals using ASTM D8073-22 may also reference the following standards for comprehensive fuel quality control:

• ASTM D1655 – Specification for Aviation Turbine Fuels
• ASTM D3948 – Test Method for Determining Water Separation Characteristics of Aviation Turbine Fuels by Portable Separometer
• ASTM D7224 – Test Method for Determining Water Separation Characteristics of Kerosine-Type Aviation Turbine Fuels Containing Additives by Portable Separometer
• ASTM D4057 – Practice for Manual Sampling of Petroleum and Petroleum Products
• ASTM D4177 – Practice for Automatic Sampling of Petroleum and Petroleum Products
• ASTM D4306 – Practice for Aviation Fuel Sample Containers for Tests Affected by Trace Contamination

These related standards support robust quality management systems by establishing procedures for sampling, testing, and maintaining the integrity of aviation fuel products.

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Keywords: ASTM D8073-22, water separation, aviation turbine fuel, Water Separation Index, surfactant detection, aviation fuel testing, small scale water separation instrument, fuel cleanliness, fuel quality control, aviation safety, ASTM standards, fuel additives

Standards Content (Sample)

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.
Designation: D8073 − 22
Standard Test Method for
Determination of Water Separation Characteristics of
Aviation Turbine Fuel by Small Scale Water Separation
Instrument
This standard is issued under the fixed designation D8073; 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* D3948 TestMethodforDeterminingWaterSeparationChar-
acteristicsofAviationTurbineFuelsbyPortableSeparom-
1.1 This test method covers a procedure to rate the ability of
eter
aviation turbine fuels to release entrained and emulsified water
D4057 Practice for Manual Sampling of Petroleum and
when passed through a water-coalescing filter.
Petroleum Products
1.2 Results are expressed as a Water Separation Index
D4177 Practice for Automatic Sampling of Petroleum and
(WSI).
Petroleum Products
D4306 Practice for Aviation Fuel Sample Containers for
1.3 The values stated in SI units are to be regarded as
standard. Tests Affected by Trace Contamination
D6300 Practice for Determination of Precision and Bias
1.3.1 Exception—Units in WSI are included.
Data for Use in Test Methods for Petroleum Products,
1.4 This standard does not purport to address all of the
Liquid Fuels, and Lubricants
safety concerns, if any, associated with its use. It is the
D7224 TestMethodforDeterminingWaterSeparationChar-
responsibility of the user of this standard to establish appro-
acteristics of Kerosine-Type Aviation Turbine Fuels Con-
priate safety, health, and environmental practices and deter-
taining Additives by Portable Separometer
mine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accor-
3. Terminology
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
3.1 Definitions:
Development of International Standards, Guides and Recom-
3.1.1 surfactant, n—in petroleum fuels, surface active ma-
mendations issued by the World Trade Organization Technical
terial (or surface active agent) that could disarm (deactivate)
Barriers to Trade (TBT) Committee.
filter separator (coalescing) elements so that free water is not
removed from the fuel in actual service.
2. Referenced Documents
3.1.1.1 Discussion—Technically, surfactants affect the inter-
facial tension between water and fuel, which affects the
2.1 ASTM Standards:
tendency of water to coalesce into droplets.
D1655 Specification for Aviation Turbine Fuels
D2550 Method of Test for Water Separation Characteristics
3.2 Definitions of Terms Specific to This Standard:
of Aviation Turbine Fuels (Withdrawn 1989)
3.2.1 sonicator, n—a device that applies ultrasonic sound
D3602 Test Method for Water Separation Characteristics of
energy to the test specimen.
Aviation Turbine Fuels (Withdrawn 1994)
3.2.1.1 Discussion—The sonicator is used to emulsify the
water and aviation fuel.
3.2.2 water separation index (WSI), n—a numerical rating
This test method is under the jurisdiction of ASTM Committee D02 on
indicating the ease of separating water from fuel by coales-
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
cence.
Subcommittee D02.J0.05 on Fuel Cleanliness.
3.2.2.1 Discussion—A high WSI indicates a fuel that sepa-
Current edition approved April 1, 2022. Published May 2022. Originally
approved in 2016. Last previous edition approved in 2021 as D8073 – 21. DOI:
rates water easily and is relatively free from surfactants.
10.1520/D8073-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
4. Summary of Test Method
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
4.1 A fixed volume of test specimen is poured into the test
the ASTM website.
beaker. The apparatus is purged with the test specimen. A
The last approved version of this historical standard is referenced on
www.astm.org. precise amount of water containing a specific dye is added to
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8073 − 22
the test beaker. The test specimen and dyed water are emulsi- 7.2.2 Reference Fluid Base—A surfactant-free aviation tur-
fied using a sonicator. The resulting emulsion is passed at a bine fuel that is used to verify proper operation and is prepared
constant rate directly to the detector, which is sensitive to the in the manner detailed in Appendix X1 and with a WSI by this
dye, to measure a reference value.The emulsion is then passed test method of 97.5 WSI to 100.0 WSI.
at the same constant rate to the detector by means of a filter 7.2.3 Reference Fluids—For checking operational perfor-
cartridge that is designed to remove entrained water. Readings manceconsistingofdispersingagent(7.2.1)addedtoreference
from the detector are taken. The water separation fluid base (7.2.2) in concentrations, on a volume basis, ranging
characteristic, the Water Separation Index (WSI), is calculated from 0 mL⁄L to 0.8 mL⁄L, in 0.1 mL⁄L increments. Reference
from the reference value and the detector readings. Results fluids may be made up in situ in the graduated beaker on an
range from 0.0 WSI to 100.0 WSI. A high value such as ad-hoc basis, or supplied pre-made up in a suitable container.
100.0 WSIindicatesatestspecimenthatcoalesceswatereasily Typical values are shown in Table 1.
and that the test specimen is relatively free of surfactants.
7.3 Cleaning Materials, technical grade.
7.3.1 Isopropyl Alcohol.
5. Significance and Use
7.4 Filter Cartridge, see A1.1.11, individually packed.
5.1 This test method provides an indication of the presence
of surfactants in aviation fuel. Like Test Methods D2550, 8. Sampling and Test Specimen Preparation
D3602, D3948, and D7224, this test method can detect
8.1 Unless otherwise agreed, samples shall be taken in
carryover traces of refinery treating residues in fuel as pro-
accordance with Practice D4057 or Practice D4177.
duced. In addition, these test methods can detect surface active
8.2 Collect the sample directly in a suitable container of a
substances added to or picked up by the fuel during handling
minimum volume of 1000 mL.
from point of production to point of use. Certain additives can
affect the WSI. Some of these substances affect the ability of
NOTE 2—The test method is known to be sensitive to trace
filter separators to separate free water from the fuel. contamination, for example from sampling containers or transfer glass-
ware. For recommended sampling containers, refer to Practice D4306.
5.2 The small scale water separation tester has a measure-
8.2.1 Epoxy-lined containers shall be visually inspected to
ment range from 0.0 WSI to 100.0 WSI.
ensure that the lining has not been damaged and that the
NOTE 1—WSI values greater than 100.0 WSI can be caused by a
reduction in the light transmittance (see A1.1.5) of the test specimen due containers are not dented.
to material that was removed during the testing process.
8.3 Do not pre-filter the sample as the filter media can
5.3 This test method was developed so refiners, fuel termi-
remove the surfactants that the test method is designed to
nal operators, pipelines, and independent testing laboratory
detect. If the test fuel contains particulate, then allow such
personnelcanrapidlyandpreciselymeasureforthepresenceof
materials to settle out before sub sampling.
surfactants, with a minimum of training, in a wide range of
8.4 Special precautions concerning sampling techniques are
locations.
discussed in Appendix X2. Wipe the container outlet thor-
oughly with a clean, lint-free wipe. Take extreme care when
6. Apparatus
pouring the sample directly into the test beaker to avoid
6.1 General—The apparatus, as detailed in Annex A1,
contamination from the top of the container.
comprises a test beaker, test beaker holder, sonicator, filter
8.5 If the sample for test is not within the temperature range
cartridge, specific dye detector, integral computer, automatic
18 °C to 29 °C, then allow the sample to stand until it is within
solenoid valves, pumps, solvent container, waste container,
this range.
particulate sieve, and temperature probe.
6.2 Pipet, single use, disposable, of suitable size. 9. Preparation of Apparatus
6.2.1 The single use disposable pipet is used to adjust the
9.1 General—Followthemanufacturer’sinstructionsforthe
volumeoftestspecimeninthetestbeakerto220 mL 610 mL.
correct set up, verification, calibration, and operation of the
apparatus.
7. Reagents and Materials
9.2 Location of Apparatus—Locate the apparatus on a solid
7.1 Dyed Water —Proprietary liquid containing water and a
surface in a well-ventilated area.
controlled amount of specific marker dye.
9.3 Filter Cartridge—At the beginning of each test, replace
7.2 Reference Materials:
the filter cartridge and wipe the sample inlet tube, thermometer
7.2.1 Dispersing Agent—Toluene solution containing
probe, and sonicator with a clean, lint-free wipe.
1 mg⁄mL of solid (100 % dry) bis-2-ethylhexyl sodium sulfo-
succinate.
TABLE 1 Reference Fluid Dispersing Agent Concentrations
Concentration (mL/L) WSI
0 100.0
Thesolesourceofsupplyofthedyedwaterknowntothecommitteeatthistime
0.2 97.6
is Stanhope-Seta/D-2 Incorporated, Falmouth, MA. If you are aware of alternative
0.4 79.8
suppliers, please provide this information to ASTM International Headquarters.
0.6 75.4
Your comments will receive careful consideration at a meeting of the responsible 0.8 68.8
technical committee, which you may attend.
D8073 − 22
9.4 Test Beaker—Before each test, ensure that the test 11.8 Press Start on the apparatus. The following steps occur
beaker is clean and dry. automatically.
NOTE 3—To avoid contamination, it is recommended to use a new test
11.9 The test specimen is pumped into the apparatus to
beaker for each test.
purge the previous sample.
9.5 Cleaning Solvent—Check visually that there is sufficient
11.10 An aliquot of dyed water, 0.06 mL 6 0.01 mL, is
isopropyl alcohol available in the solvent reservoir.
added to the test specimen in the test beaker.
9.6 Dyed Water—Checkvisuallythatthereissufficientdyed
11.11 The sonicator cycles on and off for 3 min 6 0.5 min
water in the water reservoir to cover the inlet tube.
to form a test specimen/dyed water emulsion.
9.7 Switch on the apparatus in accordance with the manu-
11.12 The emulsion is pumped to the detector and on to the
facturer’s instructions.
waste container. The detector reading is stored every second.
9.8 Purge the dyed water into a waste container to remove
11.13 The detector is cleaned with isopropyl alcohol.
trapped bubbles of air in accordance with the manufacturer’s
instructions.
11.14 The emulsion is pumped through the filter cartridge
and detector and then to the waste container.
10. Calibration, Verification and Standardization
11.15 The detector readings are stored continuously and the
10.1 Follow the manufacturer’s instructions for verification
test is completed after 5.6 min 6 0.2 min.
and calibration of the mechanical and electronic systems in the
11.16 The result is automatically calculated and displayed.
apparatus.
NOTE 4—Users are advised to check that there is less than 50 mL
(typical) left in the beaker at the end of the test.
10.2 Verification:
10.2.1 Flow Rate—Verify that the flow rate is 25 mL⁄min to
12. Calculation
30 mL⁄min, at least once every six months according to the
12.1 The Water Separation Index (WSI) is automatically
manufacturer’s instructions. If the flow rate is not correct,
calculated by an algorithm (Version 1.0) in the apparatus to the
follow the manufacturer’s instructions to diagnose and adjust.
nearest 0.1.
10.2.2 Water Volume—Verify that the correct volume of
dyed water (0.060 mL 6 0.005 mL) is dispensed following the
13. Report
manufacturer’s instructions.
13.1 The test report shall contain at least the following
10.2.3 Temperature Probe Calibration—Verify the tempera-
information:
ture at 20 °C following the manufacturer’s instructions. Reca-
13.1.1 A reference to this standard.
libratethetemperatureprobeifthetemperaturemeasurementis
13.1.2 All details necessary for complete identification of
not within 1 °C.
the product tested.
10.2.4 Overall Operation—Check the overall operation of
13.1.3 The result of the test (see Section 12) to the nearest
the apparatus using a reference fluid containing 0.4 mL⁄L of
0.1.
dispersing agent, and with reference fluid containing 0 mL⁄L
13.1.4 Any deviations, by agreement or otherwise, from the
dispersingagentasrequiredforqualitycontroloratleastevery
procedures specified, and
six months. Test the reference fluid following the procedure
13.1.5 The time and date of the test.
detailed in Section 11. Confirm that the value is between
75.0 WSI and 85.0 WSI for the 0.4 mL⁄Ldispersing agent and
14. Precision and Bias
between 97.5 WSI and 100.0 WSI for the 0 mL⁄L dispersing
14.1 General—The precision values given in 14.2 and 14.3
agent.
were derived from a 2015 laboratory study that used eight
instrumentsandindividualoperatorsatasinglelocation,totest
11. Procedure
16 samples in duplicate and in random order. The calculation
11.1 Refer to the diagram for a description of the apparatus
method that converts individual detector readings into the final
(Appendix X1).
result was improved after the ILS. Further details are available
11.2 Load a new filter cartridge into the holder.
in the research report.
14.1.1 As the precision was determined from results ob-
11.3 Wipethesonicatorandinlettubeusingalint-freewipe.
tained at a single location, the reproducibility value may not be
11.4 Gently tumble the test specimen in its original con-
comparable when results obtained at different times and
tainer end over end five times.
locations are compared, due to changes in the property of
11.5 Pour 220 mL 6 10 mL of test specimen into a clean interest: sampling, shipping, storage, environmental conditions
test beaker—if required, adjust the volume with a single use
and ot
...

This document is not an ASTM 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. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D8073 − 21 D8073 − 22 An American National Standard
Standard Test Method for
Determination of Water Separation Characteristics of
Aviation Turbine Fuel by Small Scale Water Separation
Instrument
This standard is issued under the fixed designation D8073; 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 test method covers a procedure to rate the ability of aviation turbine fuels to release entrained and emulsified water when
passed through a water-coalescing filter.
1.2 Results are expressed as a Water Separation Index (WSI).
1.3 The values stated in SI units are to be regarded as standard.
1.3.1 Exception—Units in WSI are included.
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, health, and environmental 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:
D1655 Specification for Aviation Turbine Fuels
D2550 Method of Test for Water Separation Characteristics of Aviation Turbine Fuels (Withdrawn 1989)
D3602 Test Method for Water Separation Characteristics of Aviation Turbine Fuels (Withdrawn 1994)
D3948 Test Method for Determining Water Separation Characteristics of Aviation Turbine Fuels by Portable Separometer
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D4306 Practice for Aviation Fuel Sample Containers for Tests Affected by Trace Contamination
D6300 Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products, Liquid Fuels, and
Lubricants
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.J0.05 on Fuel Cleanliness.
Current edition approved Dec. 1, 2021April 1, 2022. Published January 2022May 2022. Originally approved in 2016. Last previous edition approved in 2021 as D8073 – 16
(2021).D8073 – 21. DOI: 10.1520/D8073-21.10.1520/D8073-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8073 − 22
D7224 Test Method for Determining Water Separation Characteristics of Kerosine-Type Aviation Turbine Fuels Containing
Additives by Portable Separometer
3. Terminology
3.1 Definitions:
3.1.1 surfactant, n—in petroleum fuels, surface active material (or surface active agent) that could disarm (deactivate) filter
separator (coalescing) elements so that free water is not removed from the fuel in actual service.
3.1.1.1 Discussion—
Technically, surfactants affect the interfacial tension between water and fuel, which affects the tendency of water to coalesce into
droplets.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 sonicator, n—a device that applies ultrasonic sound energy to the test specimen.
3.2.1.1 Discussion—
The sonicator is used to emulsify the water and aviation fuel.
3.2.2 water separation index (WSI), n—a numerical rating indicating the ease of separating water from fuel by coalescence.
3.2.2.1 Discussion—
A high WSI indicates a fuel that separates water easily and is relatively free from surfactants.
4. Summary of Test Method
4.1 A fixed volume of test specimen is poured into the test beaker. The apparatus is purged with the test specimen. A precise
amount of water containing a specific dye is added to the test beaker. The test specimen and dyed water are emulsified using a
sonicator. The resulting emulsion is passed at a constant rate directly to the detector, which is sensitive to the dye, to measure a
reference value. The emulsion is then passed at the same constant rate to the detector by means of a filter cartridge that is designed
to remove entrained water. Readings from the detector are taken. The water separation characteristic, the Water Separation Index
(WSI), is calculated from the reference value and the detector readings. Results range from 0.0 WSI to 100.0 WSI. A high value
such as 100.0 WSI indicates a test specimen that coalesces water easily and that the test specimen is relatively free of surfactants.
5. Significance and Use
5.1 This test method provides an indication of the presence of surfactants in aviation fuel. Like Test Methods D2550, D3602,
D3948, and D7224, this test method can detect carryover traces of refinery treating residues in fuel as produced. In addition, these
test methods can detect surface active substances added to or picked up by the fuel during handling from point of production to
point of use. Certain additives can affect the WSI. Some of these substances affect the ability of filter separators to separate free
water from the fuel.
5.2 The small scale water separation tester has a measurement range from 0.0 WSI to 100.0 WSI.
NOTE 1—WSI values greater than 100.0 WSI can be caused by a reduction in the light transmittance (see A1.1.5) of the test specimen due to material
that was removed during the testing process.
5.3 This test method was developed so refiners, fuel terminal operators, pipelines, and independent testing laboratory personnel
can rapidly and precisely measure for the presence of surfactants, with a minimum of training, in a wide range of locations.
6. Apparatus
6.1 General—The apparatus, as detailed in Annex A1, comprises a test beaker, test beaker holder, sonicator, filter cartridge,
specific dye detector, integral computer, automatic solenoid valves, pumps, solvent container, waste container, particulate sieve,
and temperature probe.
6.2 Pipet, single use, disposable, of suitable size.
6.2.1 The single use disposable pipet is used to adjust the volume of test specimen in the test beaker to 220 mL 6 10 mL.
D8073 − 22
7. Reagents and Materials
7.1 Dyed Water —Proprietary liquid containing water and a controlled amount of specific marker dye.
7.2 Reference Materials:
7.2.1 Dispersing Agent—Toluene solution containing 1 mg ⁄mL of solid (100 % dry) bis-2-ethylhexyl sodium sulfosuccinate.
7.2.2 Reference Fluid Base—A surfactant-free aviation turbine fuel that is used to verify proper operation and is prepared in the
manner detailed in Appendix X1 and with a WSI by this test method of 97.5 WSI to 100.0 WSI.
7.2.3 Reference Fluids—For checking operational performance consisting of dispersing agent (7.2.1) added to reference fluid base
(7.2.2) in concentrations, on a volume basis, ranging from 0 mL ⁄L to 0.8 mL ⁄L, in 0.1 mL ⁄L increments. Reference fluids may be
made up in situ in the graduated beaker on an ad-hoc basis, or supplied pre-made up in a suitable container. Typical values are
shown in Table 1.
7.3 Cleaning Materials, technical grade.
7.3.1 Isopropyl Alcohol.
7.4 Filter Cartridge, see A1.1.11, individually packed.
8. Sampling and Test Specimen Preparation
8.1 Unless otherwise agreed, samples shall be taken in accordance with Practice D4057 or Practice D4177.
8.2 Collect the sample directly in a suitable container of a minimum volume of 1000 mL.
NOTE 2—The test method is known to be sensitive to trace contamination, for example from sampling containers or transfer glassware. For recommended
sampling containers, refer to Practice D4306.
8.2.1 Epoxy-lined containers shall be visually inspected to ensure that the lining has not been damaged and that the containers are
not dented.
8.3 Do not pre-filter the sample as the filter media can remove the surfactants that the test method is designed to detect. If the test
fuel contains particulate, then allow such materials to settle out before sub sampling.
8.4 Special precautions concerning sampling techniques are discussed in Appendix X2. Wipe the container outlet thoroughly with
a clean, lint-free wipe. Take extreme care when pouring the sample directly into the test beaker to avoid contamination from the
top of the container.
8.5 If the sample for test is not within the temperature range 18 °C to 29 °C, then allow the sample to stand until it is within this
range.
TABLE 1 Reference Fluid Dispersing Agent Concentrations
Concentration (mL/L) WSI
0 100.0
0.2 97.6
0.4 79.8
0.6 75.4
0.8 68.8
The sole source of supply of the dyed water known to the committee at this time is Stanhope-Seta/D-2 Incorporated, Falmouth, MA. If you are aware of alternative
suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical
committee, which you may attend.
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9. Preparation of Apparatus
9.1 General—Follow the manufacturer’s instructions for the correct set up, verification, calibration, and operation of the apparatus.
9.2 Location of Apparatus—Locate the apparatus on a solid surface in a well-ventilated area.
9.3 Filter Cartridge—At the beginning of each test, replace the filter cartridge and wipe the sample inlet tube, thermometer probe,
and sonicator with a clean, lint-free wipe.
9.4 Test Beaker—Before each test, ensure that the test beaker is clean and dry.
NOTE 3—To avoid contamination, it is recommended to use a new test beaker for each test.
9.5 Cleaning Solvent—Check visually that there is sufficient isopropyl alcohol available in the solvent reservoir.
9.6 Dyed Water—Check visually that there is sufficient dyed water in the water reservoir to cover the inlet tube.
9.7 Switch on the apparatus in accordance with the manufacturer’s instructions.
9.8 Purge the dyed water into a waste container to remove trapped bubbles of air in accordance with the manufacturer’s
instructions.
10. Calibration, Verification and Standardization
10.1 Follow the manufacturer’s instructions for verification and calibration of the mechanical and electronic systems in the
apparatus.
10.2 Verification:
10.2.1 Flow Rate—Verify that the flow rate is 25 mL ⁄min to 30 mL ⁄min, at least once every six months according to the
manufacturer’s instructions. If the flow rate is not correct, follow the manufacturer’s instructions to diagnose and adjust.
10.2.2 Water Volume—Verify that the correct volume of dyed water (0.060 mL 6 0.005 mL) is dispensed following the
manufacturer’s instructions.
10.2.3 Temperature Probe Calibration—Verify the temperature at 20 °C following the manufacturer’s instructions. Recalibrate the
temperature probe if the temperature measurement is not within 1 °C.
10.2.4 Overall Operation—Check the overall operation of the apparatus using a reference fluid containing 0.4 mL ⁄L of dispersing
agent, and with reference fluid containing 0 mL ⁄L dispersing agent as required for quality control or at least every six months. Test
the reference fluid following the procedure detailed in Section 11. Confirm that the value is between 75.0 WSI and 85.0 WSI for
the 0.4 mL ⁄L dispersing agent and between 97.5 WSI and 100.0 WSI for the 0 mL ⁄L dispersing agent.
11. Procedure
11.1 Refer to the diagram for a description of the apparatus (Appendix X1).
11.2 Load a new filter cartridge into the holder.
11.3 Wipe the sonicator and inlet tube using a lint-free wipe.
11.4 Gently tumble the test specimen in its original container end over end five times.
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11.5 Pour 220 mL 6 10 mL of test specimen into a clean test beaker—if required, adjust the volume with a single use disposable
pipet.
11.6 Put the test beaker into the test beaker holder on the apparatus.
11.7 Insert the inlet tube, sonicator and temperature probe—if required, wait for the temperature to be between 18 °C and 29 °C.
11.8 Press Start on the apparatus. The following steps occur automatically.
11.9 The test specimen is pumped into the apparatus to purge the previous sample.
11.10 An aliquot of dyed water, 0.06 mL 6 0.01 mL, is added to the test specimen in the test beaker.
11.11 The sonicator cycles on and off for 3 min 6 0.5 min to form a test specimen/dyed water emulsion.
11.12 The emulsion is pumped to the detector and on to the waste container. The detector reading is stored every second.
11.13 The detector is cleaned with isopropyl alcohol.
11.14 The emulsion is pumped through the filter cartridge and detector and then to the waste container.
11.15 The detector readings are stored continuously and the test is completed after 5.6 min 6 0.2 min.
11.16 The result is automatically calculated and displayed.
NOTE 4—Users are advised to check that there is less than 50 mL (typical) left in the beaker at the end of the test.
12. Calculation
12.1 The Water Separation Index (WSI) is automatically calculated by an algorithm (Version 1.0) in the apparatus to the nearest
0.1.
13. Report
13.1 The test report shall contain at least the following information:
13.1.1 A reference to this standard.
13.1.2 All details necessary for complete identification of the product tested.
13.1.3 The result of the test (see Section 12) to the nearest 0.1.
13.1.4 Any deviations, by agreement or otherwise, from the procedures specified, and
13.1.5 The time and date of the test.
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14. Precision and Bias
14.1 General—The precision values given in 14.2 and 14.3 were derived from a 2015 laboratory study that used eight instruments
and individual operators at a single location, to test 16 samples in duplicate and in random order. The calculation method that
converts individual detector readings into the final result was improved after the ILS. Further details are available in the research
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