9 - Lubricants and Fuels Flashcards
What do mineral oils suffer from
- Excessive volatility
- Thermal degradation
What are the values of Type I synthetic oil before and after thickeners
- 3 mm2/s at 100 °C (Before)
- 7.5 mm2/s at 100 °C (After)
What is the viscosity of Type II oils
5 mm2/s
What are the purposes of oil
- Lubricating
- Cooling
- Cleaning
- Corrosion protection
What are the two groups of engine oils
Mineral and synthetic
Where are Type I, II, and III oils used respectively
Type I - Old engines
Type II - Modern engines
Type III - Special aircraft (i.e. military)
What is vsicosity index
A fluids vicosity change according to tempreature (higher value = less effect)
What is viscosity
The internal resistance of a fluid to deformation (more viscous = thicker)
What is pour point and the value for Type II oils
The lowest tempreature that a fluid can be observed moving in a 31.75mm tube hekd horizontally for 5 seocnds
-57 °C
What is flash point and the value for Type II oils
The tempreature at which the oil gives off sufficient vapour to combust
250 °C
What is oxidation resistance
The resistance to oxidising (oxygenated oil is thicker)
What is thermal stability
The resistance to degredation at high heat
What is volatility
How easily a fluid is vaporised
What is acidity
The corrosive tendenies of the fludi
What is the % of fuel composition
16% hydrogen and 84% carbon
What are the four types of jet fuel
- Jet A1
- Jet A
- Jet B
- JP 5
What is the most common fuel in Europe
Jet A1
What is the most common fuel in America
Jet A
Why is water in fuel dangerous
Encourages ice build up, corrodes components, increases chances of flame out and increases microbial growth
What are anti-ice additives made of
Diethylene glycol
What do anti-oxidants do
Prevent formation of gum deposits on fuel system
What do static inhibitors reduce
Static build up from fuel flow
WRITE CARDS ON FUEL SAFETY
