15.9 Lubricants & Fuels Flashcards
What are the 2 oil types?
Synthetic and mineral.
Why aren’t mineral oils used?
Lack stability.
Excessively volatility.
Thermal degradation.
What synthetic oil is used?
Ester based.
Known as third generation oils.
What functions does engine oil have?
Lubricating.
Cooling.
Cleaning.
Corrosion protection.
On what engines is Type 1 synthetic oil used on?
Old gas turbine engines.
On what engines is Type 2 synthetic oil used on?
Modern gas turbine engines?
On what engines is Type 3 synthetic oil used on?
Special military aircraft engines.
What are the positives of synthetic oil?
Better viscosity.
Thermal stability.
High pressure resistance.
What is the disadvantage of synthetic oil?
Expensive.
Define viscosity index.
The effect temperature has on oil viscosity.
Define viscosity.
The internal resistance against flow.
Define pour point.
Lowest temperature oil will visibly move.
What is the pour point of type 2 synthetic oil?
-57C
Define flash point.
Lowest temp oil will give enough vapour to flash when a flame is applied.
What is the flash point of type 2 synthetic oil?
250 C
Define pressure resistance.
Oil resistance at high temperatures.
What factors affect engine performance?
Oil foaming,
Rubber shelling,
Oxidation,
Thermal stability,
Corrosiveness,
Pressure,
Coking
What is engine coking?
Carbon residue in engine due to extreme heating.
What is the flash point of jet B fuel?
-20 C
What is the flash point of JP5 fuel?
65 C
What is the freezing point of JP5 fuel?
-48 C
Where is jet A fuel primarily used?
America.
Where is jet A1 fuel primarily used?
Europe.
Where is jet B fuel primarily used?
Cold temperatures.
Where is JP5 fuel primarily used?
Military aircraft.
What fuel is used for turbine engines?
Kerosene.
What are the 2 main requirements of fuel?
A low freezing point.
Flash point low enough for good ignition but as high as possible for safe handling.
What is the density of jet A and A1 fuel?
0.81 kg/litre.
At what temp should fuels max viscosity be at?
-20 C
What is the problem with water in fuel?
Can support microbial growth.
How is dirt avoided in fuel?
Filters.
How are fuel additives measured?
Parts per million (ppm).
What is the anti ice additive for fuel?
Prist.
What are 4 additives to fuel?
Anti oxidants,
Static dissipator,
Corrosion inhibitor,
Metal de-activator.
What can be said about open oil containers and why?
They shouldn’t be re used as synthetic oil is hygroscopic.
What should be used when working with fuel tanks?
Explosion proof tools.
Special cotton clothing.
