Marine Installation Manual
2022-03
4-85
4 Ancillary Systems
4.7 Fuel oil system
X62DF-S2.0
4.7.7
Fuel oil viscosity-temperature dependency
The fuel oil viscosity depends on its temperature. This dependency is shown as
graph in
.
Figure 4
-
51 Fuel oil viscosity-temperature diagram
SM-0215
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
100 000
50 000
20 000
10 000
5 000
2 000
1 000
500
400
300
200
100
50
40
30
20
17
13
10
9
8
7
6
5
4
3
33
35
40
45
60
70
80
100
150
200
300
400
500
600
800
1 000
1 500
2 000
3 000
4 000
5 000
10 000
20 000
50 000
100 000
200 000
400 000
400 000
200 000
100 000
50 000
20 000
10 000
5 000
3 000
2 000
1 500
1 000
800
600
400
300
200
150
100
80
70
60
50
45
40
36
Seconds Saybolt
Universal
Seconds Redwood
No.1
Kinematic viscosity
[mm
2
/s (cSt)]
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160 170
0
10 20
30
40
50
60
70
80
90 100 110 120 130 140 150 160 170 180 190 200
220
240
260
280
300
320
340
[°C]
[°F]
Recommended viscosity range for HFO before fuel injection pumps
Fuel oil temperature
Example
To obtain the recommended viscosity before fuel injection pumps
a fuel oil of 380 mm
2
/s (cSt) at 50
°C must be heated up to 130
°C to 140
°C.
Oils can be pumped only with difficulty
or not at all
30
60
100
M
arine G
as Oil
(typical)
M
arine Diesel Oil
(typical)
30
60
100
180
600
50
Bunker Fuel Oil
380
380
Required viscosity range for HFO before fuel injection pumps
700 mm
2
/s at 50 °C
