ASTM D7261-07
(Test Method)Standard Test Method for Determining Water Separation Characteristics of Diesel Fuels by Portable Separometer
Standard Test Method for Determining Water Separation Characteristics of Diesel Fuels by Portable Separometer
SIGNIFICANCE AND USE
This test method provides a measure of the presence of surfactants in diesel fuels, and can be performed in the field or in a laboratory. Like Test Method D 3948 used for jet fuel, this test method can detect traces of some refinery treating chemicals left in fuel. It can also detect surface active substances added to or picked up by the fuel during handling from point of production to point of use.
Certain additives, which can act as weak surfactants, give a slightly reduced DSEP rating. Other substances which are strong surfactants give much lower DSEP ratings.
While filter separators have not been common in diesel fuel systems, they could become more prevalent with ULSD containing increased additive content to ensure clean, dry fuels in new engine designs. Weak surfactants, with slightly reduced DSEP ratings, do not affect the ability of filter separators to separate free water from the fuel. Strong surfactants give a much lower DSEP rating and adversely affect the ability of filter separators to separate free water from the fuel.
Results from this test method do not have a known relationship to the rate of water settling in tanks.
The Micro-Separometer has a measurement range from 50 to 100. Values obtained outside of those limits are undefined and invalid.
Note 2—In the event a value greater than 100 is obtained, there is a good probability that light transmittance was reduced by material contained in the fuel used to set the 100 reference level. The material was subsequently removed during the coalescing portion of the test, thus, the processed fuel had a higher light transmittance than the fuel sample used to obtain the 100 reference level resulting in the final rating measuring in excess of 100.
SCOPE
1.1 This test method covers a rapid portable means for field and laboratory use to rate the ability of diesel fuels (both neat and those containing additives) to release entrained or emulsified water when passed through fiberglass coalescing material.
1.2 This test method is applicable to diesel fuels such as D 975 Grade No. 1 and Grade No. 2 of all sulfur levels, and MIL-F-16884, naval distillate fuel (NATO F-76).Note 1
This test method is similar to Test Method D 3948 which is applicable to aviation turbine fuels.
1.3 &si-value;
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.
General Information
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Standards Content (Sample)
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An American National Standard
Designation: D 7261 – 07
Standard Test Method for
Determining Water Separation Characteristics of Diesel
1
Fuels by Portable Separometer
This standard is issued under the fixed designation D 7261; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope* D 4176 Test Method for Free Water and Particulate Con-
tamination in Distillate Fuels (Visual Inspection Proce-
1.1 This test method covers a rapid portable means for field
dures)
and laboratory use to rate the ability of diesel fuels (both neat
D 4177 Practice for Automatic Sampling of Petroleum and
and those containing additives) to release entrained or emulsi-
Petroleum Products
fied water when passed through fiberglass coalescing material.
D 4306 Practice for Aviation Fuel Sample Containers for
1.2 This test method is applicable to diesel fuels such as
Tests Affected by Trace Contamination
D 975 Grade No. 1 and Grade No. 2 of all sulfur levels, and
D 4860 Test Method for Free Water and Particulate Con-
MIL-F-16884, naval distillate fuel (NATO F-76).
tamination in Mid-Distillate Fuels (Clear and Bright Nu-
NOTE 1—This test method is similar to Test Method D 3948 which is
merical Rating)
applicable to aviation turbine fuels.
D 6426 Test Method for Determining Filterability of
1.3 The values stated in SI units are to be regarded as the
Middle Distillate Fuel Oils
standard. The values given in parentheses are for information
2.2 Military Standard:
3
only.
MIL-F-16884 Fuel, Naval Distillate (NATO F-76)
1.4 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3.1 Definitions:
priate safety and health practices and determine the applica-
3.1.1 Micro-Separometer rating (DSEP rating), n—a nu-
bility of regulatory limitations prior to use.
mericalvalueindicatingtheeaseofseparatingemulsifiedwater
from fuel by coalescence as affected by the presence of surface
2. Referenced Documents
active materials (surfactants) in the fuel.
2
2.1 ASTM Standards:
3.1.2 reference fluid, n—a reference fluid base to which
D 975 Specification for Diesel Fuel Oils
prescribed quantities of a known surface active agent have
D 1193 Specification for Reagent Water
been added.
D 3948 Test Method for Determining Water Separation
3.1.2.1 Discussion—The known surface active agent is
Characteristics of Aviation Turbine Fuels by Portable
typically bis-2-ethylhexyl sodium sulfosuccinate, commonly
Separometer
referred to as AOT, dissolved in toluene.
D 4057 Practice for Manual Sampling of Petroleum and
3.1.3 surfactants, n—in petroleum fuels, surface active ma-
Petroleum Products
terials that could disarm (de-activate) filter separator (coalesc-
ing) elements so that free water is not removed from the fuel in
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actual service.
This test method is under the jurisdiction of ASTM Committee D02 on
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
3.1.3.1 Discussion—Technically, surfactants affect the in-
D02.14 on Stability and Cleanliness of Liquid Fuels.
terfacial tension between water and fuel which affects the
Current edition approved July 1, 2007. Published August 2007. Originally
tendency of water to coalesce into droplets or not.
approved in 2006. Last previous edition approved in 2006 as D 7261–06a.
2
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
Standards volume information, refer to the standard’s Document Summary page on AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700
the ASTM website. Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
*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.
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D7261–07
3.1.4 strong surfactants, n—in petroleum fuels, surface much lower DSEP rating and adversely affect the ability of
active materials that disarm filter separator elements. filter separators to separate free water from the fuel.
3.1.4.1 Discussion—Strong surfactants can be refinery pro-
5.4 Results from this test method do not have a known
cess chemicals left in the fuel or contaminants introduced
relationship to the rate of water settling in tanks.
during transportation of the fuel.
5.5 The Micro-Separometer has
...
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