Lubrication oil is one of the highest costs associated with the opera- tion of compressors. For the average compressor operator, oil usage can
average 25 to 30% of running costs.
Managing these costs in today’s
economy is more important, as excessive lubrication erodes operators’
profitability as well as impacts the reliability of critical sealing components.
It is common practice to run break-in
lubrication rates for new or overhauled
compressors for a period of 200 hours
after start-up. This break-in period prevents excessive temperature at start-up, allows conformity of piston and
packing rings to mating surfaces and
allows debris to be carried away.
It is very often the case that the lubri-
cation levels are never scaled back to
normal levels, especially in remote lo-
cations. When operating a large fleet of
compressors, there is significant profit
that can be gained through using an
optimum lubrication system. There is
an added cost of having this additional
lubrication oil in the gas stream; the
longevity of coalescing filters can be
greatly improved when lubrication oil
rates are set to the correct levels, pre-
serving the life of the filters, increasing
the profitability of an operation.
Excessive lubrication is equally
damaging to reciprocating compressor sealing components. Increased
oil lubrication can cause hydraulic
locking of the packing case. This is
where the packing rings do not have
adequate side clearance and the
rings overheat, extrude and ultimately
fail. Another cause of over lubrication is valve stiction. Excessive oil
causes the sealing elements to stick
to the valve seat. The valve opening
and closing events are delayed and
increased pressure causes the valve
to open and close with increased velocity, which in worst cases can cause
the elements to break.
Compressor Products International
(CPI) has introduced the Proflo EOS to
specifically address these problems by
optimizing the amount of oil that is injected into a reciprocating compressor.
CPI acquired three leading compressor lubrication companies in 2010, and
the Proflo EOS has been developed as
a result of the knowledge and insight
gained from these acquisitions.
The Proflo EOS replaces the manual
adjuster on a conventional lubrication
pump. It has the ability to automatically
increase or decrease the output of the
pump by adjusting the stroke length of
the pump. Traditionally, operators have
to remove the rubber boot and screw
the manual adjustment in or out, adjusting the stroke of the pump while
watching the changes in cycle time.
The Proflo EOS is installed in a
CPI pump and monitors the amount
of oil injected into the compressor
through the use of a signal feedback
loop from a CPI Proflo Jr. or captured
proximity switch that is installed on
the lubrication system divider block.
The frequency of the pulses from the
Proflo Jr. or captured proximity switches informs the Proflo EOS as to the
change in quantity of oil.
The Proflo EOS displays all information about the status of the lubrication system on its main screen.
The Proflo EOS is set up through the
configuration of three key parameters.
The first, the divider block cycle time
set point, is the ideal number of seconds that it takes a divider block with
the optimum level of lubrication being
delivered to the compressor. The second parameter, the lubrication break-in hours, is the time during which
twice the amount of lubrication oil is
delivered to the compressor. The final
parameter, the divider block total, allows the quantity of oil consumed to
When the compressor is started, the
Eliminating Excessive Compressor
Lubrication > CPI’s Proflo EOS optimizes the amount of oil injected into a reciprocating compressor
BY LEE ALEXANDER
n The Proflo EOS is designed to eliminate
excessive lubrication by optimizing the
amount of oil that is injected into a reciprocating compressor.
Lee Alexander is Engineering Director –
Americas at CPI.