The document describes the cargo pumping system of an oil tanker, including three cargo oil pumps that can pump 5,500 cubic meters per hour of crude oil. It also describes ballast pumps, stripping pumps, and an automatic vacuum stripping system to remove residual oil from cargo tanks after unloading. The system uses a separator, vapor extraction valves, and a vacuum pump controlled by level transmitters to efficiently strip tanks as the cargo level falls during unloading operations.

1. Principal Data
Type of Cargo Crude Oil (Double Hull Oil Tanker)
Type of Ship Segregated Ballast Crude Oil Carrier
Navigation World Wide
Cargo Pumps
Manufacturer: Shinko Industries Ltd
Type: Steam turbine driven vertical centrifugal pump
No. of sets : 3
Capacity: 5,500 m3/h
Speed (Pump): 1,080 rpm
(Turbine): 7,177 rpm
Rating: 2,680kW
Stripping Pump
Manufacturer: Naniwa Pump Manufacturing Co.
Type: Two speed electrically driven, vertical two spindle screw
No. of sets: 1
Speed: 1,750/1,150 rpm
Capacity: 125/65 m3/h at 150 mth

2. Crude Oil Stripping Eductors
Manufacturer: Teamtec
No. of sets: 2
Capacity: 620 m3/h at 150 mth
Driving fluid: 1,075 m3/h at 12 kg/cm2
Ballast Pump No.1
Manufacturer: Shinko Industries Ltd.
Type: Centrifugal, vertical single stage
Prime mover: Electric motor
Capacity: 3,000 m3/h
Total head: 35m
Ballast Pump No.2
Manufacturer: Shinko Industries Ltd.
Type: Centrifugal, vertical single stage
Prime mover: Steam turbine
Capacity: 3,000 m3/h
Total head: 35m
Speed: (Pump): 1,170 rpm
(Turbine): 7,548 rpm

3. Water Ballast Stripping Eductors
Manufacturer: Teamtec
No. of sets: 2
Capacity: 200 m3/h
Driving water: 1,040m3/h at 3.5 kg/cm2 supplied by either of
the ballast pumps

9. COP
Stbd Slop Tk
Port Slop Tk
COT COW

12. ODMCS Operation

14. ppm x m3/hr
Litres per nm = -----------------------------------
1000000 x 1000 x spd (nm/hr)

15. open
shut

16. > 30 l /nm

17. CARGO OIL PUMPING SYSTEM
 CARGO OIL PUMPS & WATER BALLAST PUMPS
STEAM TURBINES (COPT & WBPT)
CARGO OIL STRIPPING PUMP
AUTOMATIC VACUUM STRIPPING SYSTEM (AVSS)

18. Materials -
NI-AI-Bronze - pump casing and Impeller.
The cartridge-type mechanical seal facilities easy maintenance.

19. Principal particulars of cargo pump
• Normal capacity – 1800 to 6050 cum/hr
• Total Head – 150 m
• Speed – 2000 to 1150 rpm
• Suction bore – 400 to 700 mm
• Discharge bore – 300 to 500 mm

20. Principal particulars of water ballast pump
• Normal capacity – 1200 to 5000 cum/hr
• Total Head – 30 to 40m
• Speed – 1180 to 890 rpm
• Suction bore – 350 to 700 mm
• Discharge bore – 300 to 500 mm

22. Features of marine pumps
• Vertical, single stage, double suction, double volute, driven by single vertical
steam turbine via intermediate shaft through bulkhead stuffing box which
keeps the engine room gas tight
• Pump casing is vertically split Into two halves at the shaft centre line, and
Joined surfaces include non asbestos seat packing.
• The suction and discharge nozzles are both provided in the rear half of the
casing and both are open in the horizontal direction 90 degrees apart, so
that dismantling or reassembling can be performed easily without
disturbing the suction and discharge piping.
• Double volute minimizes the radial thrust. While in a double volute the
pressures are not uniform at partial capacity operation the resulting forces
essentially balance each other which results in low deflection at all
operating points, thus reducing packing wear, ring wear and bearing
loading.
• Double suction also balances the axial hydraulic thrust and provides for
good suction performance due reduced NPSH
• The pump shaft is supported by ball bearing at upper and lower points. The
impeller nut threads are opposite to direction of shaft rotation to prevent
from loosening
• Casing is equipped with wear rings inserted in the groove of the casing wall

23. • Bulkhead stuffing box for the
intermediate shaft seals the gas
passing from the pump room.
• The intermediate shafts are divided
Into two parts, the upper and the
lower portions, rigidly supported by
two ball bearings in the stuffing box.
• the lower shaft is coupled with gear
coupling which is of spline type and
the length can be adjusted.

24. • Pump protection - To prevent any
accident such as explosion or for the
parameters can be monitored through a
turbine gauge board and also through
CCR
Protection
Set value
Alarm Trip
Pump casing
overheat
75 0C 80 0C
Pump
bearing
overheat
85 0C 90 0C
Pump
vibration
16mm 18 mm
Seal leakage When leaking
Discharge
pressure
As desired

25. Cargo stripping pump
• ·The stripping pumps are of robust design and can handle efficiently all grades
or oils from petrol to viscous liquids under difficult suction conditions.
• ·Air chambers are fitted on the discharge side to eliminate pipe line vibration.

27. Remote
control system
–
• The pump
speed is
controlled
by steam
valve that
is governed
by the
pneumatic
speed
controller.
• The pump
speed is
monitored
by the
pneumatic
stroke
detector
Speed
indicator
0.2 – 1 air signal

28. Engine
room
Pump
room
Drain
Tank
To slop tank
Signal air 0.2 to 1 bar
Pump
room
Gas extraction valve

30. 1. Turn on the PLC
2. After starting the cargo oil pump the cargo control console :
- Set the gas extraction valve switch to "NOR"
- Set the vacuum pump switch to "AUTO"
Set the discharge output valve to "AUTO“
3. While the liquid level in the cargo oil tank is high, the cargo oil pump located
at the bottom of the vessel performs the unloading work at the best
condition because of its high suction pressure. Therefore this vacuum
stripping system is not operated under this condition.
4. After unloading for a certain time, the liquid level in the cargo oil tank falls
down and the suction pressure of the cargo oil pump is also decreased.
Vapour generated is sucked into the separator through the suction mouth of
the cargo oil tank. The vapor mixed with oil is accumulated at the top of the
separator by sp gravity difference of oil and vapor. Consequently the
separator level begins to fall.
5. When the oil level in the separator lowers to 50%, the bypass valve is set to
close and gas extraction valve is set to open by a signal air sent from the level
transmitter. At the same time, vacuum pump continuously runs and the
discharge control valve is throttled.

31. 6. When the vapor is extracted by the vacuum pump, the separator level rises again
and if it reaches 70%, the vacuum pump continuously runs, the gas extraction
valve is closed, the bypass valve is opened and the discharge control valve is
opened.
7. The unloading is proceeding repeatedly as mentioned above to prevent the vapor
entering into the cargo oil pump whenever the vapor is accumulated in the
separator.
8. If the level in the cargo oil tank lowers further, the level around the bell mouth
fluctuates heavily and a lot of gas is sucked. While the separator level falls to
below 5% by extremely decreasing the liquid level in the cargo oil tank, the alarm
lamp indicating low separator level is displayed on the control unit. This means
unloading work enters into stripping stage.
9. If this conditions is continued about 3 minutes, the finish of stripping lamp in red
on the console flickers with buzzing and shows the completion of the unloading
work.
10. After finishing stripping, the selector is set at "COP STOP" and the cargo oil pump
is automatically stopped. Whereas it keeps on running, while at "COP RUN".