ASTM D7155-06
(Practice)Standard Practice for Evaluating Compatibility of Mixtures of Turbine Lubricating Oils
Standard Practice for Evaluating Compatibility of Mixtures of Turbine Lubricating Oils
SIGNIFICANCE AND USE
The compatibility of oils can be important for users of oil-lubricated equipment. It is well known that the mixing of two oils can produce a substance markedly inferior to either of its constituent materials. One or more of the following can occur:
5.1.1 A mixture of incompatible oils most often forms a precipitate.
5.1.2 The precipitate will form unwanted deposits in the lubrication system, plug filters and oil passageways.
5.1.3 Such events can lead to catastrophic equipment failures.
Because of such occurrences, lubricant suppliers recommend evaluating compatibility of lubricating oil of different formulations and sources prior to mixing. Equipment users most often do not have the resources to evaluate oil compatibility and must rely on their suppliers. Mixing of oils is a highly imprudent practice without first determining the compatibility.
Although new turbine oils may be compatible, in-service oil of the same type may be degraded or contaminated to such an extent that the new oil added may not be compatible with the system oil. In-service oil compatibility with new oil additions should be evaluated on a case by case basis.
The oxidation resistance of different oils of the same type can vary widely, and compatibility does not imply equivalent performance.
SCOPE
1.1 This practice covers the compatibility of mixtures of turbine lubricating oils of the same ISO VG grade and type as defined by Specification D 4304. The Tier 1 method compares the visual appearances of specific mixtures with those of the neat oils after storage at specified conditions.
1.2 If the current in-service oil is causing problems or if circumstances indicate the need for additional testing, a Tier 2 method compares selected performance properties of the mixture and its constituent oils.
1.3 The Tier 1 and Tier 2 methods can be used to evaluate new (unused) lubricant compatibility or the effects of adding new (unused) lubricant to in-service lubricant in the system.
1.4 This method does not evaluate the wear prevention characteristics, load carrying capacity, or the mechanical shear stability of lubricants mixtures while in service. If anti-wear (AW), extreme pressure (EP), or shear stability are to be evaluated, further testing of these parameters may be required.
1.4.1 Tier 1 Mixtures of the two constituent oils to be evaluated are prepared at specified proportions, stored in an oven at 65°C for 168 h, and then evaluated for changes in physical appearance.
1.4.2 Tier 1 - Mixtures of the two constituent oils to be evaluated are prepared at specified proportions, stored in an oven at 65°C for 168 h, and then evaluated for changes physical appearance and parameters detailed in 7.3.
1.5 Mixtures of the two constituent oils are evaluated in a primary testing protocol using the following standards:
1.5.1 For compatible mixtures, a supplemental (nonmandatory) testing scheme is suggested when circumstances indicate the need for additional testing the beyond Tier 2 primary recommended tests.Note 0
The oxidation stability test method should be selected based on the product type and in agreement with the lubricant supplier (see for options). Unlike other tests described in this practice, the impact on oxidation stability may not be easily interpreted with a pass/fail rating. The user is encouraged to contact the lubricant supplier for assistance in the evaluation of the data.
1.6 Sequential or concurrent testing is continued until the test requestor or user is satisfied that the intent of this practice has been met. If any mixture fails the Tier 1 visual appearance method or any of the Tier 2 primary tests, when requested, the oils are incompatible. If all mixtures pass the Tier 1 or Tier 2 tests, the oils are considered compatible by those methods.
1.7 This practice applies only to lubricating oils having characteristics suitable for evaluation by the suggested test methods. If the scope of a specif...
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Designation:D7155–06
Standard Practice for
Evaluating Compatibility of Mixtures of Turbine Lubricating
1
Oils
This standard is issued under the fixed designation D7155; 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
Pentane Insoluble Test Method D893
Copper Corrosion Test Method D130
1.1 This practice covers the compatibility of mixtures of
Rust Prevention Test Method D665
turbine lubricating oils of the same ISO VG grade and type as
Foaming Characteristics Test Method D892
Air Release Properties Test Method D3427
defined by Specification D4304. The Tier 1 method compares
Water Separability Test Method D1401
the visual appearances of specific mixtures with those of the
Oxidation Stability Test Note 1
neat oils after storage at specified conditions.
1.5.1 For compatible mixtures, a supplemental (nonmanda-
1.2 If the current in-service oil is causing problems or if
tory) testing scheme is suggested when circumstances indicate
circumstances indicate the need for additional testing, a Tier 2
the need for additional testing the beyond Tier 2 primary
method compares selected performance properties of the mix-
recommended tests.
ture and its constituent oils.
1.3 The Tier 1 and Tier 2 methods can be used to evaluate
NOTE 1—The oxidation stability test method should be selected based
new (unused) lubricant compatibility or the effects of adding on the product type and in agreement with the lubricant supplier (see
AppendixX2foroptions).Unlikeothertestsdescribedinthispractice,the
new (unused) lubricant to in-service lubricant in the system.
impact on oxidation stability may not be easily interpreted with a pass/fail
1.4 This method does not evaluate the wear prevention
rating. The user is encouraged to contact the lubricant supplier for
characteristics, load carrying capacity, or the mechanical shear
assistance in the evaluation of the data.
stability of lubricants mixtures while in service. If anti-wear
1.6 Sequential or concurrent testing is continued until the
(AW), extreme pressure (EP), or shear stability are to be
test requestor or user is satisfied that the intent of this practice
evaluated, further testing of these parameters may be required.
has been met. If any mixture fails the Tier 1 visual appearance
1.4.1 Tier 1—Mixtures of the two constituent oils to be
method or any of the Tier 2 primary tests, when requested, the
evaluated are prepared at specified proportions, stored in an
oils are incompatible. If all mixtures pass the Tier 1 or Tier 2
oven at 65°C for 168 h, and then evaluated for changes in
tests, the oils are considered compatible by those methods.
physical appearance.
1.7 This practice applies only to lubricating oils having
1.4.2 Tier 1—Mixtures of the two constituent oils to be
characteristics suitable for evaluation by the suggested test
evaluated are prepared at specified proportions, stored in an
methods. If the scope of a specific test method limits testing to
oven at 65°C for 168 h, and then evaluated for changes
those oils within a specified range of properties, oils outside
physical appearance and parameters detailed in 7.3.
that range cannot be tested for compatibility by that test
1.5 Mixtures of the two constituent oils are evaluated in a
method.
primary testing protocol using the following standards:
1.8 This practice may be used to evaluate the compatibility
Appearance (Tier 1 and Tier 2) Appendix X1
of different types and grades of oil. However, it is not intended
Kinematic Viscosity Test Method D445
Acidity Test Methods D664 and D974
to evaluate such mixtures. The user is advised to consult with
suppliers in these situations.
1.9 This practice does not purport to cover all test methods
1
This practice is under the jurisdiction ofASTM Committee D02 on Petroleum
that could be employed.
ProductsandLubricantsandisthedirectresponsibilityofSubcommitteeD02.C0on
1.10 The values stated in SI units are to be regarded as the
Turbine Oils.
standard. The values given in parentheses are for information
Current edition approved Dec. 1, 2006. Published January 2007. DOI: 10.1520/
D7155-06. only.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D7155–06
1.11 This standard does not purport to address all of the metric Karl Fischer Titration
safety concerns, if any, associated with its use. It is the D6514 Test Method for High Temperature Universal Oxi-
responsibility of the user of this standard to establish appro- dation Test for Turbine Oils
priate safety and
...
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