Maintenance and Reliability
AS I SEE IT
JIM FITCH NORIA CORPORATION
5 FACTORS to Consider
when SETTING Oil
Cleanliness TARGETS
Every plant should have the goal of
achieving reliability at the lowest
possible cost. The reliability we seek is
"optimized" reliability. This is attained
through human intervention. You could say
that reliability must be enabled. If left
alone, machines evolve to an increasingly
greater state of disrepair.
It's like the second law of thermodynamics — things naturally move from a
state of order to disorder. Let's look at
some common examples:
•• Rocks wither and crumble.
•• Iron rusts.
•• Anything that can go wrong will go
wrong (Murphy's law).
•• People grow old (as do machines).
•• Modern maintenance practices age
and become outdated.
•• Cleanliness evolves to dirtiness.
Without human intervention, the
progression to machine failure advances
undeterred, but don't be discouraged. A
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September - October 2013 | www.machinerylubrication.com
77%
of lubrication professionals set
cleanliness targets for machine
reliability, according to a recent
poll at MachineryLubrication.com
machine doesn't have to end its life as a
bucket of bolts. Lubrication is a reliability
enabler. Contamination control is an essential enabler for lubrication excellence.
Cleanliness is one of the silent assumptions of bearing reliability (and most other
machine components, too). For the others,
see the sidebar on page 3 or visit http://
www.machinerylubrication.com/Read/495/
bearing-reliability.
Dirty lubricants should be viewed in the
higher context of opportunity. It's the lucky
break that many in the reliability profession
have waiting for them, i.e., the low-hanging
fruit waiting to be harvested.
Defining Cleanliness
Cleanliness is almost a state of mind.
One person's cleanliness can be another
person's impending disaster. If you see no
evil and hear no evil, is it still possible to
have evil? If you see no dirt and feel no dirt,
are your lubricants and machines to be
considered clean?
The cleanliness we want is purposeful.
It's not for the sake of godliness but rather
for a heightened state of reliability. Achieving
cleanliness is almost always costly, yet the
benefits gained are usually multiples of this
cost. Just like we seek the optimum state of
reliability, we should also seek the optimum
state of cleanliness as a subset of reliability.
Some machines require filters, but others do
not. Some machines need 40-micron filters,
while others aren't optimized with anything
less than 1-micron filtration.
For most filtered machines, contamination levels evolve to a stable state. They rise
or fall on their own until stability is reached.
This assumes a constant ingression rate, a
constant filtration capture efficiency and a