|
Originally presented at
IMC-2003 the 18th International
Maintenance Conference
6 Steps
to Effectively Control Contamination
By Charles
Boswell –
PdMA Corporation
Click here for a
print friendly 36k PDF version
Contamination is a
leading cause of machinery failure. Maintenance and
reliability professionals need to comprehend the
destructive nature of contamination and realize the
benefits in removing contamination from their
facilities. Several areas will be discussed which will
help you reduce contamination at your site. Ways of
monitoring and controlling contamination will also be
presented. If foreign materials enter your system,
critical responses are necessary to minimize the effects
of destructive contaminants. A necessary tool for the
reliability professional is having the knowledge to
understand the signs and symptoms of contamination. In
doing so, you will be able to maximize your maintenance
dollars, thereby resulting in lower down time and
increasing your bottom line. Hopefully, the tools
discussed in this presentation will give you an outline
to effectively control contamination.
In order to effectively
control contamination, you need to follow the next 6
steps:
1.
Understand
2.
Identify
3.
Monitor
4.
Respond
5.
Remove
6.
Prevent
Contamination control
begins with a thorough understanding of what
contamination is and why it is important to keep it out
of your equipment. Basically, contamination is any
unwanted material in a lubricant. If present in your
lubricants, foreign material can become an important
cause of equipment failure. Typically, debris can lead
to failure by interfering with the lubrication film,
which results in improper lubrication. Contamination
can also promote the oxidation process, thereby
decreasing the lubricant’s ability to function properly,
which in turn will result in longer down time.
Contamination can occur in many forms. Water and
particle contamination are some of the more common
types. Fuel, soot, heat, air, and radioactive material
are other potential sources of contamination, although
they are less common. Often we think of contamination
as entering operating equipment. However, contamination
can occur even when the equipment is not in use. New
lubricants are often perceived to be free of
contamination. Unfortunately, this may not always be
the case. It is not surprising to find new lubricants
which are already contaminated. A key principle in
understanding contamination control is to realize that
it is much easier to fix a contamination problem prior
to it entering your system rather than trying to fix it
after a system has been contaminated. Keeping
contamination in check can help extend the life of your
equipment. The process of lubricant development can
result in foreign material entry. For example, the
refining process of lubricants can be an area where
contaminants can enter the lubricant. Once lubes are
dispensed to facilities there are many places where the
lubricant can be subjected to less than ideal
conditions. Storage locations, which are susceptible to
outside environments, virtually guarantee some external
contamination of lubricants will eventually occur.
Lubricant dispensing is another potential area for
pitfall as debris may have easier access depending on
the equipment being used and the procedures being
followed. If left unchecked, facility cleanliness is
another key area where contamination can become an
issue. Obviously some facilities, due to the nature of
their operations, are going to be easier to clean than
others. Even so, it is important not to overlook the
overall environment lubricant and equipment are
subjected to as a potential area for contamination
control. It is also important to comprehend the
benefits of reducing contamination. Investment of
capital and commitment from management are necessary for
the success of any maintenance program. Contamination
control is no different. Contamination control can help
increase your bottom line by reducing down time and
increasing your return on your investment. Thoroughly
understanding the many facets of contamination is
essential for controlling contamination.
The next step in
controlling contamination is identification of the
foreign material. It is important to understand what
type of contamination is present in your system. There
are primarily two major types of contamination. They
are particle and water contamination. Particle
contamination can come in many forms. Some of the more
common sources of particle contamination are air,
dust/dirt, and machinery parts. Regardless of where the
particle contamination is coming from, the end result is
prevention or hindering of proper lubrication. Particle
contamination can promote failure, oxidation, and
deplete additives. Water contamination is another major
source of contamination. If water is present in your
system it can promote corrosion and lead to wax
formation. Lube degradation, oxidation, and internal
rust are other symptoms associated with water
contamination. Water can enter the system from leaks,
malfunctioning seals, and contaminated new lubes.
Topping off equipment, if not done properly, can also
introduce water contamination into a system. Water
takes on several different forms when it is present in
lubricants. Water can show up as free water, dissolved
water, or emulsified water in a lubricant. Other types
of contaminants that may need to be identified include
fuel, soot, and glycol. These contaminants, although
less common than water and particles, can be just as
destructive and it is important to be able to properly
identify them.
If successful
contamination control is to be implemented, it is
imperative that some type of monitoring system also be
employed. A monitoring system is essential to detecting
contamination. If contamination is already present in
your system, efforts to reduce it can be effectively
measured by a successful surveillance program. In order
to successfully monitor contamination, a testing regimen
of lubricants should be performed on a regular basis.
The testing regimen employed should be capable of
measuring the different contaminants present in
lubricants. Monitoring water contamination can be
accomplished by utilizing the following tests – crackle
test, Karl Fischer, and water by distillation. Another
critical contaminant, which needs to be monitored on a
regular basis, is particle contamination. Particles can
be measured via spectroscopy, particle counting, and
ferrography analysis. Each testing option has its own
strengths and weaknesses which should be evaluated
carefully. It is important to choose a test that will
give you the necessary information to accurately
ascertain the amount of contamination. An accurate
determination of the contaminant concentration will be
crucial in determining the appropriate action plan to
remove the contaminant.
Contamination control
will fail unless there is a willingness to respond to
the signals that the program is sending. It is critical
that you take action when there are problems as well as
taking action long before problems arise. Setting
contamination limits for your systems and lubricants
will help ensure you are meeting or missing your target
limits. Acting when problems present themselves will
help ensure the root cause is identified. Failure to
respond will guarantee the necessary clues for root
cause analysis are lost forever. Utilizing the
contamination found during monitoring will help
determine the best course of action. Responding is also
critical for the continual improvement of your
contamination control program. It is also important to
realize when not to respond. Sometimes it may be
possible to refine your contamination control program to
the point where you do more harm than good. For
example, new lubricant specifications can be written to
the point where they are economically unfeasible, as
well as impractical for the operating conditions the
lubricant is subjected. It is important to have a
balanced response that will ultimately benefit the goals
of the contamination control program.
If contamination is
present in systems and lubricants, an important
component of an effective contamination control program
is the removal of the foreign material. Different
technologies are available for the removal of foreign
debris. It is important to select a technology that
will be able to remove the type of contaminant present.
Particle contamination removal can be accomplished
utilizing several different methods. Filtering is one
of the more common methods for removal of particle
debris. Filters come in a variety of shapes, sizes, and
systems. Selection of a filter removal system will be
dependent on your particular equipment, lubricant, and
maintenance budget. The key is to select a system that
will help meet the goal of particulate removal.
Electrostatic separators are another technology, which
can be employed to help remove particle debris from your
system. This technology makes use of different
electrical charges to separate particles from your
lubricant and system. Water contamination can also be
removed via several different methods. The
effectiveness of these methods will be dependent on the
type of water present. Settling tanks remove water from
lubricants by allowing the water to settle out.
Centrifugal separators and vacuum dehydrators employ
mechanical stresses to the lubricant to help facilitate
the water separation. Another method, which can help in
the removal of water by preventing its entry, is to
improve seals so water isn’t allowed to enter the
lubricant or the system.
This leads to the last
step in controlling contamination, which is preventing
contaminants from entering the system or lubricant.
When feasible, implementing changes that reduce
contamination from entering equipment and lubricants
should be undertaken. Some of the easier equipment
changes to implement are ensuring the work area is clean
and that equipment has the appropriate breather and
filter installed. Creating clean rooms for new
lubricants and lubricant storage will help ensure
contamination is not introduced when lubricants are
being dispensed. Proper dispensing equipment can also
help prevent foreign material entry. Sampling
techniques can often introduce contaminants into
systems. Methods for preventing foreign debris from
entering while pulling lubricant samples should be
continually evaluated. Sampling ports or sampling
method revisions can help prevent contamination from
entering unwanted areas.
Proving the merit of a
contamination control is an effective prevention
strategy for budgetary cutbacks. Reviewing the program
on a regular basis as well as cost justifying the
program will help ensure the efficacy of the program is
communicated to the appropriate personnel. Prevention
is the first line of defense and it should be treated as
such, as it is much harder to remove contamination after
it has entered a system. Contamination control is much
easier to achieve if foreign debris is prevented from
entering a system. The 6 steps outlined should provide
the tools necessary to effectively control
contamination.
|
