b)
With a density
of more than 0.991 g/ml at 15°C, water, in
particular and to some extent solid matter can no longer be
removed with certainty by a centrifuge. Centrifuging systems
that are claimed to be able to clean fuel oils with densities up
to 1.010 g/ml at 15°C are available. If such systems are in-
stalled, fuels with densities up to 1.010 g/ml at 15°C may be
used.
Caution!
Fuel oils having high density in combination with low viscosity
may have low ignition quality.
c)
High sulphur content
increases the risk for corrosion and
wear, particularly at low loads, and may contribute to high-
temperature deposit formation.
d)
High ash content
causes abrasive wear, and may cause high-
temperature corrosion and contributes to deposit formation.
The most harmful ash constituents are vanadium and sodium.
e)
High vanadium content
causes hot corrosion on exhaust
valves particularly in combination with high sodium content.
The corrosion increases with increased temperatures (in-
creased engine output).
f)
Sodium
contributes to hot corrosion on exhaust valves when
combined with high vanadium and sulphur content. It also
contributes to deposit formation on valves, nozzle rings, etc.
The aggressiveness of the fuels depends on, not only the
quantity, but also of the proportions of sodium and vanadium.
The worst combination is when the sodium content is about
25-40 % of the vanadium content.
g)
High conradson carbon
may cause deposit formation in com-
bustion chamber and exhaust system, particularly at low en-
gine output.
h)
High content of asphaltenes
may contribute to deposit forma-
tion in combustion chamber and exhaust systems at low loads.
Asphaltenes may under certain circumstances precipitate
from the fuel and block filters and/or cause deposits in the fuel
system. Precipitating asphaltenes may also cause excessive
centrifuge sludge.
i)
Heavy fuels
may contain considerable amounts of water (up
to 1 %). Water may also originate from the installation bunker
tanks. To avoid difficulties in the engine fuel injection system
the water content must be reduced to max. 0.3 % by centrifug-
ing.
j)
Ignition quality.
Heavy fuels may have very low ignition qual-
ity at low load operation. This may cause trouble at start and
low load operation particularly if the engine is not sufficiently
preheated. Low ignition quality may also result in long ignition
delay and as a consequence, in high firing pressure rise ratio,
which may damage engine components, e.g. piston rings.
22-9601
Fuel, Lubricating Oil, Cooling Water
02
VASA 22
02 - 5
Summary of Contents for Vasa R22
Page 14: ...Appendix B Welding Precautions 200147 00 4...
Page 42: ...02 Fuel Lubricating Oil Cooling Water 22 9601 02 22 VASA 22...
Page 60: ...03 Start Stop and Operation 22 9632 03 12 VASA 22...
Page 72: ...04 Maintenance Schedule 22 9845 III 04 12 MD HF...
Page 92: ...06 II Adjustments Clearances and Wear limits 22 9601 06 6 VASA 22...
Page 116: ...08 Operating Troubles Emergency Operation 22 9601 08 8 VASA 22...
Page 144: ...11 Crank Mechanism 22 9601 11 18 VASA 22...
Page 156: ...12 Cylinder Head with Valves 22 9601 12 12 VASA 22...
Page 164: ...13 Camshaft Driving Gear 22 9601 13 8 VASA 22...
Page 172: ...14 Valve Mechanism and Camshaft 22 9601 14 8 VASA 22...
Page 183: ...22 200520 Turbocharging and Air Cooling 15 VTR Turbocharger 15 11...
Page 189: ...15 III Turbocharging and Air Cooling 22 8604 15 6 VTR 161 251 Turbochargers...
Page 209: ...17 Fuel system 22 9601 17 8 VASA 22...
Page 229: ...18 Lubricating Oil System 22 9601 18 20 VASA 22...
Page 247: ...19 Cooling Water System 22 9601 19 18 VASA 22...
Page 261: ...21 Starting Air System 22 9601 21 10 VASA 22...