Wartsila 31 Product Manual page 60

6. Fuel Oil System
If the engines are to be operated on MDF only, heating of the fuel is normally not necessary.
In such case it is sufficient to install the equipment listed below. Some of the equipment listed
below is also to be installed in the MDF part of a HFO fuel oil system.
6.3.4.1 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:
Design pressure
Max. total pressure (safety valve)
Nominal pressure
Design temperature
Viscosity for dimensioning of electric
motor
6.3.4.2 Automatic filter (1F04)
It is recommended to select an automatic filter with a manually cleaned filter in the bypass
line. The automatic filter must be installed before the heater, between the feed pump and the
de-aeration tank, and it should be equipped with a heating jacket. Overheating (temperature
exceeding 50°C) is however to be prevented.
Design data:
Fuel viscosity
Design temperature
Design flow
Design pressure
Fineness:
- automatic filter
Maximum permitted pressure drops at 14 cSt:
- clean filter
- alarm
6.3.4.3 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:
Fuel viscosity
6-16
1.6 MPa (16 bar)
1.2 MPa (12 bar)
see chapter "Technical Data"
50°C
90 cSt
According to fuel specification
50°C
Equal to feed pump capacity
1.6 MPa (16 bar)
6 μm (absolute mesh size)
20 kPa (0.2 bar)
80 kPa (0.8 bar)
according to fuel specifications
Wärtsilä 31 Product Guide - a1 - 18 October 2016
Wärtsilä 31 Product Guide