Learjet 60 - Refuel Seledor Switch

Pilot's
Manual

Learjet 60
Each shutoff
valve is controlled by the associated pilot valve located
at the high
point in each tank . When refueling pressure is applied to
the system
through the refuel adapter, pressurized fuel is
applied to
each shutoff
valve . This pressure is applied to both sides of the
valve
poppet . If the
pilot valve is open (associated tank not full), some
of
the pressure
acting to hold the valve closed will be vented through
the pilot
valve
and
the pressure acting to unseat the poppet
will drive
the valve open
against the spring tension . When the tank
fills, the pi-
lot valve
will close, fuel pressure on both sides
of the shutoff valve
poppet will
equalize, and spring tension
will drive the valve closed .
The
solenoid valve for the fuselage
tank is located between the tank
pilot
valve and shutoff valve in
the vent line . This valve is normally
closed and must be
energized open in order to open the shutoff
valve
for filling the tank .
The valve is used to isolate the fuselage
tank if fill-
ing that tank is not
desired .
WING AND FUS
PRECHECK VALVES
The
WING and FUS PRECHECK
valves are used to check operation
of the system vent valve
and individual shutoff valves before full re-
fueling procedures are
commenced . System precheck is accomplished
with the Refuel Selector
switch set to TOTAL in order to check
all
shutoff valves . When
the WING and FUS PRECHECK valves
are set
to OPEN (grips
vertical) and refuel pressure is applied to the
refuel
adapter, fuel
will be admitted to the precheck lines
and to the tank fill
lines . The
shutoff valves will open and
fuel will flow into all tanks .
The fuel in
the precheck lines will empty into a float
basin at each pi-
lot valve . When
the basin fills the pilot valve float
will close the pilot
valve, which
causes the associated shutoff valve to
close terminating
fuel
flow . The vent valve should open when fuel
flow is initiated .
Fuel
flow should stop within 10 to 20 seconds
.
REFUEL
SELECTOR SWITCH
The
Refuel Selector switch, on the
SPPR fuel control panel, is used to
select the tank(s) to be filled during
refueling . The switch has two po-
sitions : TOTAL and PARTIAL .
The TOTAL position of the Refuel Selector switch is used to
fill the
wing and fuselage tanks simultaneously . When TOTAL is selected
and refueling pressure is applied (vent valve opens), circuits are com-
pleted to open the fuselage tank solenoid valve . When the solenoid
valve opens the fuselage tank shutoff valve will open to admit fuel
into the
fuselage tank
.
2-38
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PM-123
Original