Fuel Oil System; Acceptable Fuel Characteristics - Wartsila 31 Product Manual

Wärtsilä 31 Product Guide
6.

Fuel Oil System

6.1

Acceptable fuel characteristics

The fuel specifications are based on the ISO 8217:2012 (E) standard. Observe that a few
additional properties not included in the standard are listed in the tables. For maximum fuel
temperature before the engine, see chapter "Technical Data".
The fuel shall not contain any added substances or chemical waste, which jeopardizes the
safety of installations or adversely affects the performance of the engines or is harmful to
personnel or contributes overall to air pollution.
6.1.1 Marine Diesel Fuel (MDF)
Distillate fuel grades are ISO-F-DMX, DMA, DMZ, DMB. These fuel grades are referred to as
MDF (Marine Diesel Fuel).
The distillate grades mentioned above can be described as follows:
● DMX: A fuel which is suitable for use at ambient temperatures down to -15°C without
heating the fuel. Especially in merchant marine applications its use is restricted to lifeboat
engines and certain emergency equipment due to the reduced flash point. The low flash
point which is not meeting the SOLAS requirement can also prevent the use in other marine
applications, unless the fuel system is built according to special requirements. Also the
low viscosity (min. 1.4 cSt) can prevent the use in engines unless the fuel can be cooled
down enough to meet the min. injection viscosity limit of the engine.
● DMA: A high quality distillate, generally designated as MGO (Marine Gas Oil).
● DMZ: A high quality distillate, generally designated as MGO (Marine Gas Oil). An alternative
fuel grade for engines requiring a higher fuel viscosity than specified for DMA grade fuel.
● DMB: A general purpose fuel which may contain trace amounts of residual fuel and is
intended for engines not specifically designed to burn residual fuels. It is generally
designated as MDO (Marine Diesel Oil).
Table 6-1
Property
Viscosity, before injection pumps, min.
Viscosity, before injection pumps, max.
Viscosity at 40°C, min.
Viscosity at 40°C, max.
Density at 15°C, max.
Cetane index, min.
Sulphur, max.
Flash point, min.
Hydrogen sulfide. max.
Acid number, max.
Total sediment by hot filtration, max.
Oxidation stability, max.
Carbon residue: micro method on the 10% volume
distillation residue max.
Carbon residue: micro method, max.
Pour point (upper) , winter quality, max.
Wärtsilä 31 Product Guide - a1 - 18 October 2016
MDF specifications
1)
1)
2)
mg KOH/g
5)
Unit ISO-F-DMA ISO-F-DMZ
cSt 2.0 2.0
cSt 24 24
cSt 2 3
cSt 6 6
kg/m³ 890 890
40 40
% mass 1.5 1.5
°C 60 60
mg/kg 2 2
0.5 0.5
% mass — —
g/m 3 25 25
% mass 0.30 0.30
% mass — —
°C -6 -6
6. Fuel Oil System
ISO-F-DMB Test method ref.
2.0
24
2
11 ISO 3104
900 ISO 3675 or 12185
35 ISO 4264
2 ISO 8574 or 14596
60 ISO 2719
2 IP 570
0.5 ASTM D664
3)
0.1 ISO 10307-1
25 4) ISO 12205
— ISO 10370
0.30 ISO 10370
0 ISO 3016
6-1