Fuel System - Cirrus SR22 Pilot Operating Handbook

Section 7 Cirrus Design
Airplane Description SR22

Fuel System

An 81-gallon usable wet-wing fuel storage system provides fuel for
engine operation. The system consists of a 42-gallon capacity (40.5-
gallon usable) vented integral fuel tank and a fuel collector/sump in
each wing, a three position selector valve, an electric boost pump, and
an engine-driven fuel pump. Fuel is gravity fed from each tank to the
associated collector sumps where the engine-driven fuel pump draws
fuel through a filter and selector valve to pressure feed the engine fuel
injection system. The electric boost pump is provided for engine
priming and vapor suppression.
Each integral wing fuel tank has a filler cap in the upper surface of
each wing for fuel servicing. Access panels in the lower surface of
each wing allow access to the associated wet compartment (tank) for
inspection and maintenance. Float-type fuel quantity sensors in each
wing tank and each collector tank supply fuel level information to the
fuel quantity indicators. Positive pressure in the tank is maintained
through a vent line from each wing tank. Fuel, from each wing tank,
gravity feeds through strainers and a flapper valve to the associated
collector tank in each wing. Each collector tank/sump incorporates a
flush mounted fuel drain and a vent to the associated fuel tank.
The engine-driven fuel pump pulls filtered fuel from the two collector
tanks through a three-position (LEFT-RIGHT-OFF) selector valve. The
selector valve allows tank selection. From the fuel pump, the fuel is
proportioned to the induction airflow, metered to a flow divider, and
delivered to the individual cylinders. Excess fuel is returned to the
selected tank.
A dual-reading fuel-quantity indicator is located in the center console
next to the fuel selector in plain view of the pilot. Fuel shutoff and tank
selection is positioned nearby for easy access.
Fuel system venting is Essential to system operation. Blockage of the
system will result in decreasing fuel flow and eventual engine fuel
starvation and stoppage. Venting is accomplished independently from
each tank by a vent line leading to a NACA-type vent mounted in an
access panel underneath the wing near each wing tip.
7-54 P/N 13772-001
Revision A7