ASTM D2595-22

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Designation: D2595 − 17 D2595 − 22
Standard Test Method for
Evaporation Loss of Lubricating Greases Over Wide-
Temperature Range
This standard is issued under the fixed designation D2595; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope*
1.1 This test method covers the determination of evaporation loss of lubricating greases at temperatures between 93 °C and 316 °C
(200 °F and 600 °F). This test method is intended to augment Test Method D972, which is limited to 149 °C (300 °F).
1.2 The values stated in SI units are to be regarded as the standard. The values 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. For specific safety information, see 5.2.
1.4 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:
A240/A240M Specification for Chromium and Chromium-Nickel Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and
for General Applications
D217 Test Methods for Cone Penetration of Lubricating Grease
D972 Test Method for Evaporation Loss of Lubricating Greases and Oils
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
E2877 Guide for Digital Contact Thermometers
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this test method, refer to Terminology D4175.
3.1.2 lubricating grease, n—a semi-fluid to solid product of a thickener in a liquid lubricant.
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.G0.03 on Physical Tests.
Current edition approved June 1, 2017Dec. 1, 2022. Published July 2017December 2022. Originally approved in 1967. Last previous edition approved in 20082017 as
ε1
D2595 – 96D2595 – 17.(2008) , which was withdrawn January 2017 and reinstated June 2017. DOI: 10.1520/D2595-17. DOI: 10.1520/D2595-22.
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’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
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D2595 − 22
FIG. 1 Thermocouple Arrangement
3.1.2.1 Discussion—
The dispersion of the thickener forms a two-phase system and immobilizes the liquid lubricant by surface tension and other
physical forces. Other ingredients are commonly included to impart special properties. D217
3.1.3 thickener, n—in lubricating grease, a substance composed of finely divided particles dispersed in a liquid lubricant to form
the product’s structure.
3.1.3.1 Discussion—
The thickener can be fibers (such as various metallic soaps) or plates or spheres (such as certain non-soap thickeners) which are
insoluble or, at most, only very slightly soluble in the liquid lubricant. The general requirements are that the solid particles be
extremely small, uniformly dispersed, and capable of forming a relatively stable, gel-like structure with the liquid lubricant. D217
4. Summary of Test Method
4.1 A weighed sample of grease in an evaporation cell is placed in a heating device maintained at the desired test temperature.
Heated air is passed over the grease surface for 22 h 6 0.1 h. The loss in weight of the sample due to evaporation is determined.
5. Significance and Use
5.1 The loss of volatile materials from greases and oils can adversely affect the original performance characteristics of a lubricant
and, therefore, could be a significant factor in evaluating a lubricant for a specific use. Such volatiles can also be considered
contaminants in the environment in which the lubricant is to be used. Correlation between results from this test method and service
performance has not been established.
5.2 The test method can be used at any specified temperature between 93 °C and 316 °C (200 °F and 600 °F) that may be agreed
upon by the user of the method. (Warning—This test method should not be used at temperatures which exceed the flash point of
the base oil of the grease.)
NOTE 1—The specified flow of air, 2.58 g ⁄min 6 0.02 g ⁄min, (2 L ⁄min at standard temperature and pressure), assumes dry air. It is not known that the
original work involved dry air but it has since been shown that this can be a factor in reproducibility and should be addressed. Air with a dew point of
less than 10 °C at standard temperature and pressure will be satisfactory.
6. Apparatus
6.1 Evaporation Cell Assembly (Fig. 1) consisting of the following items:
6.1.1 Sample Cup, A.
6.1.2 Hood, B.
D2595 − 22
SECTION OF GREASE SAMPLE CUP ALL DIMENSIONS 60.0156 in. (60.4 mm) UNLESS OTHERWISE SPECIFIED
FIG. 2 Evaporation Test Cell
6.1.3 Cover and Eduction Tube, C—These items (6.1.1 to 6.1.3) shall be constructed from a stainless steel conforming to Type
304 of Specification A240/A240M. Design dimensions and dimensional tolerances shall be as shown in Fig. 2 and Fig. 3.
6.1.4 Gasket—Shall be of a heat-resistant (315 °C (600 °F)) material. A gasket cut from 3.2 mm ( ⁄8 in.) TFE-fluorocarbon sheet
has been found to work successfully.
6.1.5 Thermocouple Tube and Supports— The tube shall be of stainless steel having an outside diameter of 3.18 mm 6 0.025 mm
(0.125 in. 6 0.001 in.) and fitted with stainless steel centering devices as shown in Fig. 1.
6.2 Air Supply System—Shall consist of a calibrated flowmeter, filtering device, and accessory valves capable of delivering and
maintaining a flow of dust-free air at the rate of 2.58 g ⁄min 6 0.02 g ⁄min between 15.6 °C and 29.4 °C (60 °F and 85 °F) (2 L ⁄min
at standard temperature and pressure).
6.3 Heating Device—An aluminum block heater similar to that shown in Fig. 4 has been found to be satisfactory. The aluminum
block heater found to be satisfactory consists of an aluminum block approximately 254 mm (10 in.) wide, 356 mm (14 in.) long,
and 203 mm (8 in.) deep. It is completely and adequately insulated on all sides. It is heated by two 650 W cartridge-type heaters
and a 500 W ring-type
...