Principles of a Regenerative
Turbine Coro-Flo
®
Pump
The Corken Coro-Flo
®
Pump is a special type of pump
known as a turbine or regenerative pump. The liquid flows
into the inlet nozzle and into the passageway on each side
of an impeller (the rotating element) and is recirculated
constantly between the vanes or teeth of the impeller and
this passageway as the impeller rotates. The fluid makes
a complete revolution in the pump case and is diverted
out the outlet nozzle. The horsepower required to drive
the pump increases as the differential pressure increases,
but the capacity decreases at the same time. Differential
pressure is the difference between the pressure at the
inlet of the pump and at the outlet of the pump.
The impeller is the only moving part and has no contact
with the casing. Consequently, practically no wear
occurs to the impeller, even when pumping volatile
liquids such as LP-gas or ammonia which have little
lubricating qualities.
Exclusive Features of Your
Coro-Flo
®
Pump
The pumping of volatile liquids is one of the most difficult
of all pumping jobs. Unlike other pumping operations,
more attention must be given to the design, manufacture
installation, and operation of the pump.
In addition to being a pump type especially suited for
handling volatile liquids, your Coro-Flo® pump has a
number of features which help to make it more easily
operated and maintained.
• Available with three mounting options: close-coupled
(C-model), frame-mounted (F-model), and direct-
mounted (D-model).
• Underwriters’ Laboratories, Inc. have tested and
inspected the C-model pumps and have listed them for
use in the handling of LP-gas and ammonia fluids. The
nameplate on the pump shows the UL label.
• Ductile iron, the metal with the strength of steel, has
been used in the manufacture of this pump for parts
under pressure of the liquid.
• The impeller floats on a shaft and may be replaced
easily without disturbing the piping or driver by simply
removing the cover. No special tools are needed.
• The mechanical seal assembly may be replaced
easily by removing the cover and the impeller and
without disturbing the piping or driver. No special
tools are needed.
• The pump nozzles may be rotated into four different
positions, 90 degrees apart, if desired.
• A bypass connection, 3/4" pipe thread, has been
located on the outlet nozzle to make the piping of the
pump more simple.
• Pressure gauge connections, 1/4" pipe thread, have
been located on the outlet nozzle.
• Motors on models C10, C12, C13 and C14 are explosion-
proof, Class I, Group D - UL and CSA listed. The C10,
C12 and C13 motors are all single phase. 60 Hertz
(50/60 Hertz on C13 only), 3450 RPM, 115/230 volt.
The C14 motor is three-phase, 60 Hertz, 3450 RPM,
230/460 bolts. Corken provides two manual motor
starters for models C10, C12 and C13. One is motor-
mounted and the other is wall-mounted. These motors
(after pump serial number TS185540) are provided with
a conduit seal in the 3/4" NPT rigid galvanized steel
nipple, fulfilling the 1996 requirement of NFPA 70-NEC,
paragraphs 501.5.a.1 & 3. Separate motor starters with
overload protection must be provided for the model C14
and all F series pumps.
4
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