In installations where MDF is fed directly from the MDF tank (1T06) to the circulation pump, a suction
strainer (1F07) with a fineness of 0.5 mm shall be installed to protect the circulation pump. The suction
strainer can be common for all circulation pumps.
Design data:
5 x the fuel consumption of the engine
Capacity
1.6 MPa (16 bar)
Design pressure
1.0 MPa (10 bar)
Max. total pressure (safety valve)
150°C
Design temperature
Pressure for dimensioning of electric motor (
Δ
P):
0.7 MPa (7 bar)
- if MDF is fed directly from day tank
0.3 MPa (3 bar)
- if all fuel is fed through feeder/booster unit
500 cSt
Viscosity for dimensioning of electric motor
Safety filter (1F03)
The safety filter is a full flow duplex type filter with steel net. The filter should be equipped with a heating
jacket. The safety filter or pump and filter unit shall be installed as close as possible to the engine.
Design data:
according to fuel specification
Fuel viscosity
150°C
Design temperature
Equal to circulation pump capacity
Design flow
1.6 MPa (16 bar)
Design pressure
37
μ
m (absolute mesh size)
Filter fineness
Maximum permitted pressure drops at 14 cSt:
20 kPa (0.2 bar)
- clean filter
80 kPa (0.8 bar)
- alarm
Overflow valve, HFO (1V05)
When several engines are connected to the same feeder/booster unit an overflow valve is needed between
the feed line and the return line. The overflow valve limits the maximum pressure in the feed line, when the
fuel lines to a parallel engine are closed for maintenance purposes.
The overflow valve should be dimensioned to secure a stable pressure over the whole operating range.
Design data:
Equal to circulation pump (1P06)
Capacity
1.6 MPa (16 bar)
Design pressure
150°C
Design temperature
0.2...0.7 MPa (2...7 bar)
Set-point (
Δ
p)
Pilot fuel feed pump, MDF (1P13)
The pilot fuel feed pump is needed in HFO installations. The pump feed the engine with MDF fuel to the
pilot fuel system. No HFO is allowed to enter the pilot fuel 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:
1 m
3
/h per engine
Capacity
1.6 MPa (16 bar)
Design pressure
1.0 MPa (10 bar)
Max. total pressure (safety valve)
66
Product Guide Wärtsilä 34DF - 3/2012
Product Guide
6. Fuel System
