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November - December 2016
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www.machinerylubrication.com
PERSPECTIVE
The table on the right can be used as a general reference for the
maximum service application of greases according to the thick-
ener in the formulation.
The chart at the bottom of the page compares how grease
consistency changes with temperature in two greases: simple
lithium and lithium complex. The latter is classified as a high-tem-
perature grease even in formulas with mineral oil.
Strengths and Weaknesses of
High-temperature Lubricants
When choosing a high-temperature lubricant, you must be
aware of the potential drawbacks in order to select the best possible
product. The table on page 30 provides the strengths and weak-
nesses of common synthetic lubricants.
These charts are intended for general reference only, as various
technologies in the marketplace may result in different specifica-
tions or performance.
Remember, when selecting high-temperature lubricants, follow
the appropriate methodology to determine the right option
according to your equipment conditions and reliability objectives.
Always weigh the pros and cons, and analyze the expected economic
and operational benefits so you can be sure you are choosing the
correct lubricant for your high-temperature application
.
About the Author
Alejandro Meza is a senior technical consultant with Noria Corporation.
He has more than 20 years of experience in the lubricant industry, technical
services, quality assurance, training, consulting and development in the United
States, Brazil, Mexico and the Americas region. Contact Alejandro at ameza@
noria.com to learn how Noria can help you
choose the right lubricant for your
high-temperature applications.
TYPE
DROPPING
POINT, °C
MAXIMUM SERVICE
TEMPERATURE, °C
Simple Lithium 175 120 to 135
Lithium
Complex
250+ 150 to 175
Polyurea 250+ 150 to 175
Calcium 90 60 to 70
Anhydrous
Calcium
140
90 to 110
Calcium
Complex
260+ 190 to 220
Modified Clay 280+ 190 to 220
Sodium 190 135 to 150
Sodium
Complex
250+ 170 to 190
1000
100
10
1
0 50 100 150 200 250
Significant
Differnce
Apparent
Viscosity,
Poise
Complex vs.
Simple Soaps
LITHIUM COMPLEX
SIMPLE LITHIUM
TEMPERATURE,
°C
Significant Difference
Comparison of How Grease Consistency Changes with Temperature in Two Greases
