circulating oil system, squirt oil into the bearing once installation is
complete to prevent potential dry start conditions.
Controlling Tank Rust
The air headspace on steel circulating tanks can become rusty
over time. Rust is a hard contaminant that can cause abrasion,
promote oxidation and emulsify water. If there are no other options
to control water ingression and rust, consider coating the area of
the tank exposed to air and water condensation with a thin layer of
grease that is compatible with the circulating oil. This should be
done after a system drain and tank cleaning. The grease can be
easily applied with a clean squeegee.
Don't Forget the Coolant
Even with all the emphasis on proper monitoring and mainte-
nance of lubricants in machinery, the coolant is often forgotten or
overlooked. Yet coolant condition monitoring and replacement are
just as critical to prevent crevice corrosion in cooling systems and to
improve reliability. When replacing water-based coolants, always
dilute using only distilled or deionized water — never tap water. In
many locations, the chloride content in tap water is quite corrosive
and will greatly increase corrosion rates in cooling systems.
Filtering High-viscosity Oil
When using a filter cart with high-viscosity gear oil, it is helpful to
completely drain the unit's filter housing and hoses as well as to
replace the filter element. When filtering oils that are ISO VG 680 or
higher, the temperature needs to be 30 degrees C or warmer. At
many plants, the slowdown season is normally during winter, making
filtering of high-viscosity oils nearly impossible due to the tempera-
ture. Because some oils can be extremely expensive, changing them
is out of the question. Enclosing the work area with tarps and using
a heater can help. If possible, completely shut down and lock out the
equipment, take the oil to the shop or another heated building and
filter it there. Use a particle counter, and when you get the recom-
mended ISO code, put it back into the machine.
ML
www.machinerylubrication.com
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September - October 2014
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