| Today's Tip: Sediment in Sight Gauges |
One of our fan pumps recently lost an oil-filled bearing due to lack of oil
in the sump. The oil level sight gauge used on
this pump indicated that the pump was full but
actually it was not. The pipe coming out of the
side of the pump to the level gauge was plugged
with sediment and would not let oil out of the
sight gauge to give a true oil level reading.
To prevent this, lube technicians need to drain
sight gauges periodically to confirm proper functioning.
(Submitted by Dave Nestman, Lube Mechanic, Howe
Sound Pulp And Paper. Thanks Dave!)
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From "The Oil Analysis Handbook".
Soot is abrasive. Intuitively one might think of carbon black as being relatively ‘soft’, however soot particles, in any form, are harder than steel. Engine oils are formulated with additives that keep
soot in suspension and stop it from agglomerating but, as with other additives, they are sacrificial. Once a certain level of soot loading is reached (typically around 3 percent by mass for most engine oils), the soot particles will no longer be able to be carried by the oil and sludgy deposits will form. Not only is soot abrasive but it also causes the viscosity of the oil to increase.
More information about the book "The Oil Analysis Handbook"
| Lube-Trivia:
Lube Concoction Results |
Test your knowledge and prepare for ICML lubrication and oil analysis certification.
QUESTION: When a SAE 20 is blended with a SAE 40, will the resulted viscosity be closer to SAE 30 or SAE 60?
Get
the answer.
| Q & A: Dielectric Instruments for Oil Screening |
"What is the
meaning of dielectric constant (DC) in a lubricant’s
performance and its monitoring? We have an instrument
in our predictive maintenance department that reports
these units, and we do not know how to use it."
There are several instruments for used oil analysis
based on DC. The DC is a measure of how a material
transmits electric currents, and is a simple number
that is the relative ratio of the speed of an electric
field in a material compared to the speed of the electric
field in a vacuum.
Different materials
have different DC *vacuum =1, Mineral oils =2.1 -
2.4, PAG 6.6 – 7.7, metals = infinite, etc.)
When using this
instrument, it is important to first obtain the original
value for DC of the new oil in order to compare it
with the values of the used oil. Any change (increase)
in DC from its original value is an indicator of contamination,
or a change in chemistry of the oil, such as oxidation.
Other factors
that can change the DC of used oil include: changes
in acid number, base number, additive depletion, wrong
oil, water and wear metals. The only factor that lowers
the DC in the oil is fuel dilution.
These instruments
are intended to screen your oil samples to monitor
lubricant health and contamination. Changes in DC
greater than 0.01 indicate a change in the lubricant
that requires the sample to be sent to the laboratory
for complete oil analysis.
Check with your
instrument supplier for more information specific
to the variations in technology that can affect the
measuring capacities and results.
Gerardo
Trujillo, Noria Latin America
