Wartsila ?31DF Series Product Manual page 121

Wärtsilä 31DF Product Guide
6.4.6.4 Safety filter, HFO (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:
Fuel viscosity
Design temperature
Design flow
Design pressure
Filter fineness
Maximum permitted pressure drops at 14 cSt:
6.4.6.5 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:
Capacity
Design pressure
Design temperature
DBAE248994
According to fuel specification
150°C
Equal to circulation pump capacity
1.6 MPa (16 bar)
34 μm (absolute mesh size)
(ß = 75, ISO16889)
50
Clean filter: 20 kPa (0.2 bar)
Alarm: 80 kPa (0.8 bar)
Equal to circulation pump (1P06)
1.6 MPa (16 bar)
150°C
6. Fuel Oil System
6-37