Fuel Selector Valve; Fuel Pump Operation - Cirrus DESIGN SR22T Pilot Operating Handbook

Section 7
Airplane and Systems Description
contamination and grade. The fuel must be sampled prior to each
flight. A sampler cup is provided to drain a small amount of fuel from
the wing tank drains, the collector tank drains, and the gascolator
drain. If takeoff weight limitations for the next flight permit, the fuel
tanks should be filled after each flight to prevent condensation.

Fuel Selector Valve

A fuel selector valve, located at the rear of the center console,
provides the following functions:
• LEFT Allows fuel to flow from the left tank
• RIGHT Allows fuel to flow from the right tank
• OFF Cuts off fuel flow from both tanks
The valve is arranged so that to feed off a particular tank the valve
should be pointed to the fuel indicator for that tank. To select RIGHT or
LEFT, rotate the selector to the desired position. To select Off, first
raise the fuel selector knob release and then rotate the knob to OFF.

Fuel Pump Operation

Fuel pump operation and engine prime is controlled through the Fuel
Pump rocker switch located adjacent to the fuel selector valve.
To prevent over-priming during low power settings, the system uses a
lockout relay that only allows HIGH BOOST/PRIME fuel pump
operation when manifold pressure is greater than 24 in.Hg or, - to
facilitate engine starting - when engine speed is less than 500 RPM.
Whenever the engine parameters fall outside these specifications,
pressing HIGH BOOST/PRIME will turn the pump on in low-speed
mode.
Selecting BOOST energizes the fuel pump in low-speed mode
regardless of engine speed or manifold pressure to deliver a
continuous 4-6 psi boost to the fuel flow for vapor suppression in a hot
fuel condition.
The fuel pump operates on 28 VDC supplied through the 5-amp FUEL
PUMP circuit breaker on MAIN BUS 2.
7-40
Cirrus Design
SR22T
P/N 13772-003
Original Issue