stroyed. These are useless for operation under
wet conditions, and can be considered to have
poor water resistance.
wet conditions, and can be considered to have
poor water resistance.
There are many effects that water has on
grease, and no single test can cover them all.
Many of the tests are useful tools; however, the
results are subject to the personal judgment of
the test operator and much skill is needed to
interpret their meaning. ASTM Method D 1264,
"Water Washout Characteristics of Lubricating
Greases," is one method of evaluating this prop-
erty.
grease, and no single test can cover them all.
Many of the tests are useful tools; however, the
results are subject to the personal judgment of
the test operator and much skill is needed to
interpret their meaning. ASTM Method D 1264,
"Water Washout Characteristics of Lubricating
Greases," is one method of evaluating this prop-
erty.
Apparatus: The equipment necessary for this
test are: (1) a 204 K Conrad-type 8-ball bearing
equipped with front and rear shields having a
specified clearance, (2) a reservoir, (3) a bear-
ing housing mount, (4) a circulating pump, (5) a
drive motor, (6) a constant heat 'source, and (7)
a thermometer or thermocouple.
test are: (1) a 204 K Conrad-type 8-ball bearing
equipped with front and rear shields having a
specified clearance, (2) a reservoir, (3) a bear-
ing housing mount, (4) a circulating pump, (5) a
drive motor, (6) a constant heat 'source, and (7)
a thermometer or thermocouple.
Test Procedure: The ball bearing and shields
are first cleaned and weighed. Then the bearing
is packed with 4 grams of the test grease and
rotated at 600 rpm for 1 hour while a jet of water
is sprayed at either 100° F or 175° F on the
bearing housing. After this period, the bearings
and shields are removed, dried, and weighed.
The percentage weight of the grease lost is
determined.
are first cleaned and weighed. Then the bearing
is packed with 4 grams of the test grease and
rotated at 600 rpm for 1 hour while a jet of water
is sprayed at either 100° F or 175° F on the
bearing housing. After this period, the bearings
and shields are removed, dried, and weighed.
The percentage weight of the grease lost is
determined.
Report: The average of duplicate tests is re-
ported as the percentage weight of grease
washed out at the test temperature. The tem-
perature at which the bearing assembly and
ported as the percentage weight of grease
washed out at the test temperature. The tem-
perature at which the bearing assembly and
grease were dried is indicated. This is significant
in some cases because some weight loss may
be experienced because of oil evaporation In
greases containing low-viscosity oils.
in some cases because some weight loss may
be experienced because of oil evaporation In
greases containing low-viscosity oils.
Precision Reproducibility: Results obtained by
each of two laboratories are not considered
suspect unless they differ by more than 20 per-
cent washout at 100° F or 25 percent washout at
175° F.
each of two laboratories are not considered
suspect unless they differ by more than 20 per-
cent washout at 100° F or 25 percent washout at
175° F.
Because of the poor precision of this test other
procedures are under study by ASTM.
procedures are under study by ASTM.
Significance: Test results are useful for pre-
dicting the probable behavior of a grease in a
shielded (not positively sealed) bearing exposed
to the washing action of water. They are a
measure of the solubility of a grease in water
and give limited information on the effect of
water on the grease structure. They say nothing
about the rust preventive properties of the
grease.
dicting the probable behavior of a grease in a
shielded (not positively sealed) bearing exposed
to the washing action of water. They are a
measure of the solubility of a grease in water
and give limited information on the effect of
water on the grease structure. They say nothing
about the rust preventive properties of the
grease.
The test is a laboratory procedure and should
not be considered equivalent to a service eval-
uation. Results on greases tested by this method
may differ from service results because of
differences in housing or seal design. Therefore
a grease that proves unsatisfactory according to
this test, may be satisfactory under service
conditions if the housing or seal design is
suitable.
not be considered equivalent to a service eval-
uation. Results on greases tested by this method
may differ from service results because of
differences in housing or seal design. Therefore
a grease that proves unsatisfactory according to
this test, may be satisfactory under service
conditions if the housing or seal design is
suitable.
(FIST 2-4 11/90)
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