ASTM D938-92(1998)e1
(Test Method)Standard Test Method for Congealing Point of Petroleum Waxes, Including Petrolatum
Standard Test Method for Congealing Point of Petroleum Waxes, Including Petrolatum
SCOPE
1.1 This test method covers determination of the congealing point of petroleum waxes, including petrolatum.
1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.
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.
Note 1—This test method is an alternative to Test Method D 127. Results obtained are usually lower than the results obtained by Test Method D 127 - IP 133, the amount of the deviation varying with the nature of the petroleum wax.
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An American National Standard
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Designation: D 938 – 92 (Reapproved 1998) British Standard 5088
Designation: 76/70(95)
Standard Test Method for
Congealing Point of Petroleum Waxes, Including
Petrolatum
This standard is issued under the fixed designation D 938; 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.
e NOTE—Added thermometer 54C to 6.1 editorially in November 2003.
1. Scope 4. Summary of Test Method
1.1 This test method covers determination of the congealing 4.1 A sample of wax is melted and a droplet is made to
point of petroleum waxes, including petrolatum. adhere to the bulb of a thermometer. Using a prewarmed flask
1.2 The values stated in inch-pound units are to be regarded as an air jacket, the droplet on the bulb is allowed to cool at a
as the standard. The values given in parentheses are for fixed rate until it congeals. The congealing point is observed as
information only. the temperature at which the droplet ceases to flow as the
1.3 This standard does not purport to address all of the thermometer is turned.
safety concerns, if any, associated with its use. It is the
5. Significance and Use
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 5.1 Congealing point is a wax property that is of interest to
many petroleum wax consumers. The procedure described here
bility of regulatory limitations prior to use.
measures the temperature at which a sample being cooled
NOTE 1—This test method is an alternative to Test Method D 127.
develops a “set” or resistance to flow. At that temperature, the
Results obtained are usually lower than the results obtained by Test
wax may be at or close to the solid state, or it may be semisolid
Method D 127 – IP 133, the amount of the deviation varying with the
and quite unctuous, depending on the composition of the wax
nature of the petroleum wax.
or petrolatum being tested. In the case of petrolatums, congeal-
2. Referenced Documents
ing property is associated with the formation of a gel structure
2.1 ASTM Standards: as the sample cools.
D 127 Test Method for Drop Melting Point of Petroleum
2 6. Apparatus
Wax Including Petrolatum
6.1 Thermometer, having the following range and conform-
E 1 Specification for ASTM Thermometers
ing to the requirements prescribed in Specification E 1 or in the
3. Terminology
specifications for IP Standard Thermometers:
3.1 Definition:
Thermometer Number
Temperature Range ASTM IP
3.1.1 congealing point, n— of petroleum wax, that tempera-
20 to 100°C 54C 18C
ture at which molten petroleum wax, when allowed to cool
68 to 213°F 54F 18F
under prescribed conditions, ceases to flow.
6.2 Erlenmeyer Flask, 125-mL, glass, to serve as a ther-
mometer jacket.
This test method is under the jurisdiction of ASTM Committee D-2 on 6.3 Cork or Rubber Stopper, for attaching the thermometer
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
to the Erlenmeyer flask.
D02.0M on Petroleum Wax.
Current edition approved Aug. 15, 1992. Published October 1992. Originally
published 1947. Last previous edition D 938 – 86.
Annual Book of ASTM Standards, Vol 05.01.
Annual Book of ASTM Standards, Vol 14.03.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D 938 – 92 (1998)
7. Procedure as the congealing point of the specimen under test. If the
variation of two determinations is greater than 1°C (2°F), make
7.1 Adjust the thermometer through the stopper so that the
one additional determination and record the average of the
bottom of the bulb will be 10 to 15 mm above the bottom of the
three determinations as the congealing point.
Erlenmeyer flask when the stopper is fitted snugly in the flask.
After making this adjustment, remove the thermometer and
NOTE 3—Operators should periodically check themselves for compli-
ance with this turning rate. The brief pause time is not to be included in
stopper from the flask, being careful not to change the position
the 2 to 3-s rotation time.
of the stopper relative to the thermometer stem.
7.2 Place approximately 50 g of sample, which is represen-
8. Report
tative of the material under inspection, in a porce
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