Hydrocarbon Processing - October 2021 - GP-35

MAINTENANCE AND RELIABILITY
known as inductive coupled plasma (ICP). ICP identifies and
quantifies elements found in additives, contaminants and wear
metals. It is important to trend additive elements, such as calcium,
zinc, magnesium and phosphorus, as they can help identify
a mixture of fluids, and an increase in their concentration
can also be indicative of overextended oil drains, oil evaporation
loss or high oil consumption rates. Contaminant elements,
such as silicon, can be extremely detrimental. For example, in
landfill gas applications, silicon enters the engine via fuel gas in
the form of organo-silicon compounds. Coolant contamination
can be identified by rising levels of sodium and/or potassium.
Wear metals such as iron, copper, tin and lead should also be
trended over time to establish what is normal for a particular
engine. Where the trend deviates from normal or if wear metal
levels exceed the OEM listed limits, further action should be
taken. When an increase in wear metal is observed, it is always
good to see where oxidation, nitration and TAN are trending as
a more degraded fluid can contribute to corrosive wear. Due to
particle size detection limits of the ICP test method, oil filter
analysis greatly complements wear metal analysis and is recommended
as a best practice.
Other elements are likely to be found in a stationary gas engine
oil, so it is important for operators to consult their OEM
manual and lubricant specialists, both of which can provide
advice specific to an operation. If operators can leverage the
analysis data as a whole, then it can provide clear insight into
the lubricant's condition. This enables operators to make more
informed maintenance decisions.
Using the data. Once the data from the used oil analysis is in
hand, the next step is to manage and interpret it quickly to enable
effective and informed decision-making. Reliability and
maintenance teams are increasingly taking advantage of online
lab diagnostic tools and customized asset management reporting,
which supports efficient and effective data analysis.
Such tools can allow rapid sample registration and sample
results to be accessed from tablets or mobile devices, so maintenance
and reliability professionals can access the latest insights
at any time. Dashboard graphs help prioritize critical results
and detect abnormalities within the results-e.g., an increase in
wear metals or reduction in fluid viscosity. Utilizing oil diagnostics
helps keep an operation one step ahead by using the latest
technology to proactively track where maintenance is needed
now and predict where it will be needed in the future.
Making informed decisions. A successful used oil analysis
program can enable operators to determine the mechanical condition
of the engine. The trending and analysis of wear metals
allows the identification of problems in their infancy. This is a
significant value proposition, as issues can be dealt with before
they escalate (FIG. 5). For example, it is known that oxidation and
nitration are inevitable in stationary gas engines, but by trending
the rate of degradation, the oil can be replaced before it becomes
too acidic, which could otherwise lead to corrosive wear.
Analysis of used oil data can also provide insight into why
problems are occurring in the engine and can provide clues
to help pinpoint the source of certain wear and degradation
modes. As an example, in lean-burn gas engines, the rate of oxidation
is usually at least two times that of nitration (model deFIG.
5. Reliable fluid analysis is critical to protecting critical,
high-performing engines.
pendent). If the rate of nitration becomes even with or exceeds
the rate of oxidation, this can indicate an overly rich air-to-fuel
ratio. Digging deeper into this data allows operators to address
the causes of certain conditions, as correlations are often present.
It can also enable more informed lubricant choices to be
made to optimize the operation. Analysis could show that operating
conditions are detrimental to the lifecycle of the oil and
that a different stationary gas engine oil, specially designed for
certain conditions, would be more suitable for the operation.
Carrying out a successful used oil analysis program can put
operators in a good position to extend the lifecycle of the oil,
but it cannot be the only factor. Physical inspections of mechanical
components must supplement used oil analysis, and only
then can operators make an informed, holistic decision. That
being said, OEMs should be consulted before extending drain
intervals, as this can void warranty if not managed correctly.
When effectively using all of this data to make informed decisions,
operators can also begin to make changes that add to the
long-term protection of their equipment.
Used oil analysis may be common practice, but operators
can always find additional efficiencies. It is important to know
what should be analyzed and why, as well as to possess a deeper
understanding of what is causing the results and what that
means. Combined with proper oil sampling techniques, this
can provide the opportunity to realize the full value of used oil
analysis to produce a clear picture of what is happening to the
oil and the engine.
This combination enables operations to make proactive,
informed decisions to identify issues before they become too
expensive to repair and to optimize their operation. Combined
with physical inspections and oil consumption rate trending, it
provides users the opportunity for efficiencies, improved performance
and the ability to get the most out of the oil being
used in the engine. GP
CLINTON BUHLER is the Senior Technical Services Advisor at
HollyFrontier Lubricants and Specialties, which includes the
Petro-Canada Lubricants brand. With more than 17 yr of gas
engine experience, he specializes in working with customers
in realizing the full potential and value of their lubricants in
critical gas plant and power generation equipment.
Gas Processing & LNG | SEPTEMBER/OCTOBER 2021 35
Hydrocarbon Processing - October 2021

Table of Contents for the Digital Edition of Hydrocarbon Processing - October 2021
