Maintworld 1/2020

ASSET MANAGEMENT
Self-Inflicted Reliability Problems
of Rotating Machinery
The root cause of poor reliability can come from many sources. You may
experience reliability issues due to the age of your plant. Or perhaps poor design
decisions were made. Or the original construction crew cared nothing for reliability.
And there may be other reasons, outside of your control, that resulted in the
reliability problems you experience today.
IN ANY RELIABILITY IMPROVEMENT
initiative, you will need to address
these issues, but first, you need to address
the self-inflicted reliability issues.
“But we don't have self-inflicted reliability
problems."
It is a bitter pill to swallow, but yes,
you do. But that is good news because
it is much easier to deal with the selfinflicted
root causes than the inherent
reliability problems you adopted.
What are self-inflicted
reliability problems?
In order to determine why equipment
fails prematurely (or why you experience
slowdowns, safety incidences, or quality
problems), you could go through a
detailed failure modes, effects, and criticality
(FMECA) analysis process, or you
could perform root cause failure analysis
12 maintworld 1/2020
JASON TRANTER,
ARP-E/L, CMRP
Mobius Institute
(RCFA) after each failure occurs. Or you
could learn from the experience gained
at thousands of plants around the world
and consider some of the most common
root causes of equipment failure - we will
focus on rotating machinery.
The number three cause of
reliability problems
Let’s start with the most obvious problems
and then we will work backward to
their root causes.
Most equipment, like motors, pumps,
fans, compressors, and turbines, are
designed to run for many, many years
without unplanned downtime. Yes, they
may have some components that wear
out, but many of the components, such
as the bearings and gears, are designed to
give years of trouble-free operation. But
that assumes that all of the parts were
installed correctly, the components are
precision-aligned, the bearings and gears
are correctly lubricated, all fasteners are
tightened to the correct tension, there
is no resonance, belts are tightened to
the correct tension, and the rotors are
precision-balanced.
And it assumes that the equipment
is operated as per design. Pumps, for
example, should be operated at their
“best efficiency point.”
What happens at your plant? Do these