Wartsila 31 Product Manual page 61

Wärtsilä 31 Product Guide
Design temperature
Design flow
Design pressure
Fineness
Maximum permitted pressure drops at 14 cSt:
- clean filter
- alarm
6.3.4.4 Pressure control valve, MDF (1V02)
The pressure control valve is installed when the installation includes a feeder/booster unit for
HFO and there is a return line from the engine to the MDF day tank. The purpose of the valve
is to increase the pressure in the return line so that the required pressure at the engine is
achieved.
Design data:
Capacity
Design temperature
Design pressure
Set point
6.3.4.5 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.
If MDF viscosity in day tank drops below stated minimum viscosity limit then it is recommended
to install an MDF cooler into the engine fuel supply line in order to have reliable viscosity
control.
Design data:
Max. pressure drop, fuel oil
Max. pressure drop, water
Margin (heat rate, fouling)
Design temperature MDF/HFO installa-
tion
Wärtsilä 31 Product Guide - a1 - 18 October 2016
50°C
Larger than feed/circulation pump capacity
1.6 MPa (16 bar)
25 μm (absolute mesh size)
20 kPa (0.2 bar)
80 kPa (0.8 bar)
Equal to circulation pump
50°C
1.6 MPa (16 bar)
0.4...0.7 MPa (4...7 bar)
80 kPa (0.8 bar)
60 kPa (0.6 bar)
min. 15%
50/150°C
6. Fuel Oil System
6-17