Condition monitoring (or how to
prevent unexpected breakdowns!)
Condition Based Maintenance (CBM),
using tools such as vibration analysis,
thermal imaging, ultrasonic detectors
and oil analysis, is now clearly recognised
as being the key to running an efficient
maintenance program. By comparison,
planned maintenance, or worse still
breakdown maintenance, strategies are
expensive and unreliable, and particularly
in these harsh financial times can prove
to be the death sentence for a production
facility.
Whilst they are using CBM tools, service
and maintenance personnel bring
another valuable skill to the job – they
use their eyes and ears! For example,
a vibration analyser indicates that a
mixing vessel bearing is likely to fail
prematurely sometime in the next two
months - but why has this happened?
A simple inspection may show that the
drive coupling is worn, which can then be
replaced along with the bearing. This is
Proactive Maintenance, identifying the
root cause of the problem and correcting
it. What if the worn coupling hadn’t been
changed? – The bearing would have been
replaced only to prematurely wear out
again.
It is generally accepted that the three
main causes of premature bearing failure
in rotating equipment are due to:
• Out of balance
• Misalignment
• Lack of lubrication
Fortunately, thanks to modern
technology, all of these conditions can
be detected very easily using extremely
affordable easy to use handheld vibration
analysers.
Out of balance shows up as a large
amplitude vibration at the running speed
of the machine.
24 FDPP - www.fdpp.co.uk
Misalignment on the other hand generally
shows up as an additional large vibration
at twice the running speed.
Lack of lubrication will result in high
frequency vibration (bearing noise) that
is not necessarily audible to the human
ear but can easily be detected by a
vibration analyser.
Finally, machine looseness will typically
generate vibrations at higher harmonics
of the machine running speed (e.g. three
times running speed and above).
These days, once diagnosed, all these
faults can easily be remedied in-house
using affordable easy to use tools such
as laser alignment systems, in-situ rotor
balancers or even a simple grease gun!
TECHNOLOGY TO THE RESCUE!
Not so very long ago CBM tools used to
be expensive and difficult to use. But
thanks to modern technology, these tools
are now not only extremely affordable;
they are also very easy to use.
The TPI 9070 (pictured) is a simple to
use, incredibly low cost vibration analyser
that records, analyses and displays
vibration signals at the push of a button.
The unit includes colour coded alarm
levels based on ISO vibration values and
bearing condition. It also incorporates
a fully zoomable vibration frequency
spectrum (FFT) display with cursor, and
diagnoses out of balance, misalignment,
looseness and bearing faults.
TPI manufactures and supplies a complete
range of low cost, high performance,
easy to use vibration analysis tools for
maintenance engineers. TPI’s products
are all incredibly easy to use, from the
simple one-button-to-press, TPI 9070 to
its top-of-the-range units for condition
based maintenance, machine balancing
and alignment.
The TPI 9080 (Intrinsically Safe ATEX
version also available) is the latest in
a line of easy to use high specification
maintenance products and perfectly
complements TPI’s family of condition
based monitoring and inspection systems,
offering high level functionality and
capability at extremely low cost. The TPI
9080 is capable of storing machine routes
(as simple lists) that can be followed
by even the lowest skilled operative to
collect and store vibration readings for
transfer to the included free VibTrend PC
trending software. This allows faults to
be identified well ahead of the point at
which they start to become a problem
that could result in excessive bearing wear
for example.