ASTM D2500-05
(Test Method)Standard Test Method for Cloud Point of Petroleum Products
Standard Test Method for Cloud Point of Petroleum Products
SIGNIFICANCE AND USE
For petroleum products and biodiesel fuels, cloud point of a petroleum product is an index of the lowest temperature of their utility for certain applications.
Note—All dimensions are in milllimetres. FIG. 1 Apparatus for Cloud Point Test
SCOPE
1.1 This test method covers only petroleum products and biodiesel fuels that are transparent in layers 40 mm in thickness, and with a cloud point below 49C.Note 1
The interlaboratory program consisted of petroleum products of Test Method D 1500 color of 3.5 and lower. The precisions stated in this test method may not apply to samples with ASTM color higher than 3.5.
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. For specific hazard statements, see Section 7.
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Standards Content (Sample)
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An American National Standard
Designation:D2500–05 British Standard 4458
Designation: 219/82
Standard Test Method for
1
Cloud Point of Petroleum Products
This standard is issued under the fixed designation D2500; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) 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* mono-estersandglycerin.Thefueltypicallymaycontainupto
14differenttypesoffattyacidsthatarechemicallytransformed
1.1 This test method covers only petroleum products and
into fatty acid methyl esters (FAME).
biodiesel fuels that are transparent in layers 40 mm in
3.1.2 biodiesel blend, n—a blend of biodiesel fuel with
thickness, and with a cloud point below 49°C.
petroleum-based diesel fuel designated BXX, where XX is the
NOTE 1—The interlaboratory program consisted of petroleum products
volume % of biodiesel.
ofTestMethodD1500colorof3.5andlower.Theprecisionsstatedinthis
3.1.3 cloud point, n—in petroleum products and biodiesel
test method may not apply to samples withASTM color higher than 3.5.
fuels, the temperature of a liquid specimen when the smallest
1.2 This standard does not purport to address all of the
observable cluster of hydrocarbon crystals first occurs upon
safety concerns, if any, associated with its use. It is the
cooling under prescribed conditions.
responsibility of the user of this standard to establish appro-
3.1.3.1 Discussion—To many observers, the cluster of wax
priate safety and health practices and determine the applica-
crystals looks like a patch of whitish or milky cloud, hence the
bility of regulatory limitations prior to use. For specific hazard
nameofthetestmethod.Thecloudappearswhenthetempera-
statements, see Section 7.
ture of the specimen is low enough to cause wax crystals to
form. For many specimens, the crystals first form at the lower
2. Referenced Documents
circumferential wall of the test jar where the temperature is
2
2.1 ASTM Standards:
lowest.Thesizeandpositionofthecloudorclusteratthecloud
D1500 Test Method for ASTM Color of Petroleum Prod-
point varies depending on the nature of the specimen. Some
ucts (ASTM Color Scale)
samples will form large, easily observable, clusters, while
E1 Specification forASTM Liquid-in-GlassThermometers
others are barely perceptible.
2.2 Energy Institute Standard:
3.1.3.2 Discussion—Upon cooling to temperatures lower
3
Specifications for IP Standard Thermometers
than the cloud point, clusters of crystals will grow in multiple
directions; for example, around the lower circumference of the
3. Terminology
testjar,towardsthecenterofthejar,orverticallyupwards.The
3.1 Definitions of Terms Specific to This Standard:
crystals can develop into a ring of cloud along the bottom
3.1.1 biodiesel, n—afuelcomprisedofmono-alkylestersof
circumference,followedbyextensivecrystallizationacrossthe
long chain fatty acids derived from vegetable oils or animal
bottom of the test jar as temperature decreases. Nevertheless,
fats, designated B100.
the cloud point is defined as the temperature at which the
3.1.1.1 Discussion—Biodiesel is typically produced by a
crystalsfirstappear,notwhenanentireringorfulllayerofwax
reaction of vegetable oil or animal fat with an alcohol such as
has been formed at the bottom of the test jar.
methanol or ethanol in the presence of a catalyst to yield
3.1.3.3 Discussion—In general, it is easier to detect the
cloud point of samples with large clusters that form quickly,
1
suchasparaffinicsamples.Thecontrastbetweentheopacityof
This test method is under the jurisdiction of ASTM Committee D02 on
PetroleumProductsandLubricantsandisthedirectresponsibilityofSubcommittee
the cluster and the liquid is also sharper. In addition, small
D02.07 on Flow Properties.
brightly-reflective spots can sometimes be observed inside the
Current edition approved July 1, 2005. Published August 2005. Originally
´1 cluster when the specimen is well illuminated. For other more
approved in 1966. Last previous edition approved in 2002 as D2500–02 .
2
difficult samples, such as naphthenic, hydrocracked, and those
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
samples whose cold flow behavior have been chemically
Standards volume information, refer to the standard’s Document Summary page on
altered, the appearance of the first cloud can be less distinct.
the ASTM website.
3
Therateofcrystalgrowthisslow,theopacitycontrastisweak,
AvailablefromEnergyInstitute,61NewCavendishSt.,London,EnglandWIM
8AR.
*A Summary of Changes section ap
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