ASTM D6185-11(2017)
(Practice)Standard Practice for Evaluating Compatibility of Binary Mixtures of Lubricating Greases
Standard Practice for Evaluating Compatibility of Binary Mixtures of Lubricating Greases
SIGNIFICANCE AND USE
5.1 The compatibility of greases can be important for users of grease-lubricated equipment. It is well known that the mixing of two greases can produce a substance markedly inferior to either of its constituent materials. One or more of the following can occur. A mixture of incompatible greases most often softens, sometimes excessively. Occasionally, it can harden. In extreme cases, the thickener and liquid lubricant will completely separate. Bleeding can be so severe that the mixed grease will run out of an operating bearing. Excessive syneresis can occur, forming pools of liquid lubricant separated from the grease. Dropping points can be reduced to the extent that grease or separated oil runs out of bearings at elevated operating temperatures. Such events can lead to catastrophic lubrication failures.
5.1.1 Because of such occurrences, equipment manufacturers recommend completely cleaning the grease from equipment before installing a different grease. Service recommendations for grease-lubricated equipment frequently specify the caveat–do not mix greases under any circumstances. Despite this admonition, grease mixing will occur and, at times, cannot be avoided. In such instances, it would be useful to know whether the mixing of two greases could lead to inadequate lubrication with disastrous consequences. Equipment users most often do not have the resources to evaluate grease compatibility and must rely on their suppliers. Mixing of greases is a highly imprudent practice. Grease and equipment manufacturers alike recognize such practices will occur despite all warnings to the contrary. Thus, both users and suppliers have a need to know the compatibility characteristics of the greases in question.
5.2 There are two approaches to evaluating the compatibility of grease mixtures. One is to determine whether such mixtures meet the same specification requirements as the constituent components. This approach is not addressed by this practice. Instead, this practice...
SCOPE
1.1 This practice covers a protocol for evaluating the compatibility of one or three binary mixtures of lubricating greases by comparing their properties or performance relative to those of the neat greases comprising the mixture.
1.2 Three properties are evaluated in a primary testing protocol using standard test methods: (1) dropping point by Test Method D566 (or Test Method D2265); (2) shear stability by Test Methods D217, 100 000–stroke worked penetration; and (3) storage stability at elevated-temperature by change in 60-stroke penetration (Test Method D217). For compatible mixtures (those passing all primary testing), a secondary (nonmandatory) testing scheme is suggested when circumstances indicate the need for additional testing.
1.3 Sequential or concurrent testing is continued until the first failure. If any mixture fails any of the primary tests, the greases are incompatible. If all mixtures pass the three primary tests, the greases are considered compatible.
1.4 This practice applies only to lubricating greases having characteristics suitable for evaluation by the suggested test methods. If the scope of a specific test method limits testing to those greases within a specified range of properties, greases outside that range cannot be tested for compatibility by that test method. An exception to this would be when the tested property of the neat, constituent greases is within the specified range, but the tested property of a mixture is outside the range because of incompatibility.
1.5 This practice does not purport to cover all test methods that could be employed.
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.7 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 env...
General Information
Relations
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: D6185 − 11 (Reapproved 2017)
Standard Practice for
Evaluating Compatibility of Binary Mixtures of Lubricating
1
Greases
This standard is issued under the fixed designation D6185; 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 responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
1.1 This practice covers a protocol for evaluating the
mine the applicability of regulatory limitations prior to use.
compatibility of one or three binary mixtures of lubricating
For specific safety information, see 7.2.3.
greases by comparing their properties or performance relative
1.8 This international standard was developed in accor-
to those of the neat greases comprising the mixture.
dance with internationally recognized principles on standard-
1.2 Three properties are evaluated in a primary testing
ization established in the Decision on Principles for the
protocol using standard test methods: (1) dropping point by
Development of International Standards, Guides and Recom-
Test Method D566 (or Test Method D2265); (2) shear stability
mendations issued by the World Trade Organization Technical
by Test Methods D217, 100 000-stroke worked penetration;
Barriers to Trade (TBT) Committee.
and (3) storage stability at elevated-temperature by change in
60-stroke penetration (Test Method D217). For compatible
2. Referenced Documents
mixtures (those passing all primary testing), a secondary
2
2.1 ASTM Standards:
(nonmandatory) testing scheme is suggested when circum-
D217 Test Methods for Cone Penetration of Lubricating
stances indicate the need for additional testing.
Grease
1.3 Sequential or concurrent testing is continued until the
D566 TestMethodforDroppingPointofLubricatingGrease
first failure. If any mixture fails any of the primary tests, the
D972 Test Method for Evaporation Loss of Lubricating
greases are incompatible. If all mixtures pass the three primary
Greases and Oils
tests, the greases are considered compatible.
D1092 Test Method for Measuring Apparent Viscosity of
Lubricating Greases
1.4 This practice applies only to lubricating greases having
D1263 Test Method for Leakage Tendencies of Automotive
characteristics suitable for evaluation by the suggested test
3
Wheel Bearing Greases (Withdrawn 2010)
methods. If the scope of a specific test method limits testing to
D1264 Test Method for Determining the Water Washout
those greases within a specified range of properties, greases
Characteristics of Lubricating Greases
outsidethatrangecannotbetestedforcompatibilitybythattest
D1403 Test Methods for Cone Penetration of Lubricating
method. An exception to this would be when the tested
Grease Using One-Quarter and One-Half Scale Cone
property of the neat, constituent greases is within the specified
Equipment
range, but the tested property of a mixture is outside the range
D1478 Test Method for Low-Temperature Torque of Ball
because of incompatibility.
Bearing Grease
1.5 This practice does not purport to cover all test methods
D1742 Test Method for Oil Separation from Lubricating
that could be employed.
Grease During Storage
1.6 The values stated in SI units are to be regarded as
D1743 Test Method for Determining Corrosion Preventive
standard. No other units of measurement are included in this
Properties of Lubricating Greases
standard.
D1831 Test Method for Roll Stability of Lubricating Grease
D2265 Test Method for Dropping Point of Lubricating
1.7 This standard does not purport to address all of the
Grease Over Wide Temperature Range
safety concerns, if any, associated with its use. It is the
1 2
This practice is under the jurisdiction ofASTM Committee D02 on Petroleum For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom- contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
mittee D02.G0.01 on Chemical and General Laboratory Tests. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Dec. 15, 2017. Published February 2018. Originally the ASTM website.
3
approved in 1997. Last previous edition approved in 2011 as D6185 – 11. DOI: The last approved version of this historical standard is referenced on
10.1520/D6185-11R17. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Cons
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.