12 FD151 Gas Compressor
2.6 CRANKCASE LUBRICATION
Non-detergent oil is recommended for Corken
compressors. Detergent oils tend to keep wear
particles and debris suspended in the oil, whereas
non-detergent oils let them settle to the bottom of the
crankcase. When non-detergent oils are not
available, detergent oils usually may be substituted
successfully, although compressors handling
ammonia, amine, or imine gases are notable
exceptions. These gases react with the detergent
and cause the crankcase oil to become corrosive and
contaminated. Figures 2.6A & B show recommended
oil viscosities and crankcase capacities.
New or rebuilt units should be filled with oil
through the opening behind the compressor
nameplate. This provides excellent lubrication for
the crossheads on initial startup (see Figure 2.6C).
Synthetic lubricants are generally not necessary.
Please consult the factory if you are considering the
use of a synthetic oil.
2.7 PURGING AND DRAINING OF
DISTANCE PIECES
The key to leakage control and oil-free operation of
Corken compressors is the distance piece. Distance
pieces are equipped with tapped holes to purge,
vent and drain. Proper connections to and from
these tapped holes are essential for optimum
compressor performance.
Since some oil will pass the bottom packing set,
regular draining of the distance piece is essential
to maintain oil-free operation (See Figure 2.7).
Corken recommends checking and draining the
distance piece once a week for units in
continuous-duty operation.
Installing a drain cock
to the distance piece drain will help simplify draining
of the distance piece.
Compressors with "A"-Style packing arrangements
are shipped with all connections plugged. The
distance piece will pressurize in this type application.
Corrosive gases should be prevented from
entering the crankcase, since even minute
amounts of leakage into the crankcase can
seriously contaminate the crankcase oil. To
prevent this contamination, the distance piece
may be purged, buffered, or both purged and
buffered by a dry, clean, non-corrosive gas like air
or nitrogen.
Figure 2.7
Flywheel
Side
Figure 2.6C
Remove this plug periodically to
drain distance piece.
Typical connection points for distance
piece drain, vent or purge lines.
Note: Fill crankcase with oil through this opening
