Circulation pump, MDF (1P03)
The circulation pump maintains the pressure at the injection pumps and circulates the fuel in the system.
It is recommended to use a screw pump as circulation pump. A suction strainer with a fineness of 0.5 mm
should be installed before each pump. There must be a positive static pressure of about 30 kPa on the
suction side of the pump.
Design data:
5 x the total consumption of the connected engines
Capacity
1.6 MPa (16 bar)
Design pressure
1.0 MPa (10 bar)
Max. total pressure (safety valve)
see chapter "Technical Data"
Nominal pressure
50°C
Design temperature
90 cSt
Viscosity for dimensioning of electric motor
Flow meter, MDF (1I03)
If the return fuel from the engine is conducted to a return fuel tank instead of the day tank, one consumption
meter is sufficient for monitoring of the fuel consumption, provided that the meter is installed in the feed
line from the day tank (before the return fuel tank). A fuel oil cooler is usually required with a return fuel tank.
The total resistance of the flow meter and the suction strainer must be small enough to ensure a positive
static pressure of about 30 kPa on the suction side of the circulation pump.
There should be a by-pass line around the consumption meter, which opens automatically in case of ex-
cessive pressure drop.
Fine filter, MDF (1F05)
The fuel oil fine filter is a full flow duplex type filter with steel net. This filter must be installed as near the
engine as possible.
The diameter of the pipe between the fine filter and the engine should be the same as the diameter before
the filters.
Design data:
according to fuel specifications
Fuel viscosity
50°C
Design temperature
Equal to feed/circulation pump capacity
Design flow
1.6 MPa (16 bar)
Design pressure
37
μ
m (absolute mesh size)
Fineness
Maximum permitted pressure drops at 14 cSt:
20 kPa (0.2 bar)
- clean filter
80 kPa (0.8 bar)
- alarm
MDF cooler (1E04)
The fuel viscosity may not drop below the minimum value stated in Technical data. When operating on
MDF, the practical consequence is that the fuel oil inlet temperature must be kept below 45°C. Very light
fuel grades may require even lower temperature.
Sustained operation on MDF usually requires a fuel oil cooler. The cooler is to be installed in the return line
after the engine(s). LT-water is normally used as cooling medium.
Design data:
2.5 kW/cyl
Heat to be dissipated
80 kPa (0.8 bar)
Max. pressure drop, fuel oil
60 kPa (0.6 bar)
Max. pressure drop, water
min. 15%
Margin (heat rate, fouling)
Product Guide Wärtsilä 34DF - 3/2012
59
Product Guide
6. Fuel System
