engine fuel systems Flashcards
what type of engine driven fuel pump is widely used other than gear and piston pumps
rotary vane pump
what is the purpose of the dump portion of a pressurizing and dump valve
to drain fuel from the manifolds after engine shutdown
what is the purpose of the pressurizing portion of a pressurizing and dump valve
to provide primary and secondary fuel flow to the dual-line duplex fuel nozzles
what type of fuel pump can VARY the amount of fuel discharged regardless of speed
variable displacement pump
what happens to excess fuel not required by an engine in a constant displacement pump
a pressure relief valve bypasses excess fuel
what keeps dual element constant displacement fuel pump operating if one gear element seizes
shear section of the drive shaft
a gear type pump is classified in what category
constant displacement
what are the two categories of turbine engine fuel pumps
constant displacement and variable displacement
what is the purpose of a turbine engine driven fuel pump
to deliver a continuous supply of fuel at the proper pressure at all times
what do the divided fuel flows of a turbine engine duplex fuel nozzle produce in the fuel
two spray patterns
what do you look for during external inspection of an engine driven fuel pump
leaks and security of mounting
what is the purpose of fuel boost pumps
to supply fuel under pressure to engine driven fuel pumps
what does the use of fuel boost pumps help prevent
engine driven fuel pump cavitation and vapor lock
what is commonly used type of fuel boost pump
the centrifugal type
what are the causes of vapor lock
low fuel pressure
high fuel temperature
excessive fuel turbulence
why is vapor lock serious
the fuel flow may be completely blocked
what are the purposes of the main fuel strainers
to collect water and sediment, and keep foreign matter out the carburetor
what are the purposes of fuel selector valves
shutting fuel flow off
for tank and engine selection
cross-feed
fuel transfer
what unit in a turbine engine fuel system is susceptible to the formation of ice
the fuel filter
what is the safety feature in an engine fuel system micron filter
bypass valve
what methods are most often used to prevent ice in turbine engine fuel filters
a heat exchanger utilizing heat from engine bleed air or engine lubricating oil
