Piper Malibu PA-46-310P Pilot Operating Handbook page 265

SECTION 7
DESCR/OPERA TION
PIPER AIRCRAFT CORPORATION
PA-46-310P, MALIBU
in each main wheel well. Collector/ sump tanks vent back to the main tanks
by a fourth line located forward of the main spar. The main tanks vent to the
atmosphere by non-icing vents installed in the most outboard forward
access panels of each wing tank. Reverse fuel flow from collector tanks to
main tanks is prevented by 2 flapper check valves installed in each collector
U
tank. Collector tank sumps are the lowest points in the fuel system, and each
has a drain valve for draining collector and main tanks.
WARNING
Avoid prolonged uncoordinated flight to
prevent uncovering of fuel tank outlets and
subsequent fuel starvation.
Each tank separately vents air in and fumes out to equalize pressure
with ambient conditions. This is accomplished through combination valves
in non-icing fuel tank vents located at the most outboard, forward tank
access panels.
NOTE
When opening the fuel tank filler cap, a rush of
air will normally be heard and felt. This is
caused by the large volume of vapor space in
the wing tank, which is under a slight pressure
differential. This pressure is the minimum
required to open the combination valve in the
vent and does not represent a hazard.
CAUTIONS
Do not insert objects into the wing vent as
damage to the combination valve could result
in fuel leakage.
A plugged vent could result in fuel starvation.
If a restricted vent is suspected, select the
opposite tank immediately. Monitor the
suspect wing and land as soon as possible.
REPORT: VB-1200
7-16
ISSUED: JANUARY 11, 1984
REVISED: JANUARY IS, 1986
V
V