Piper Malibu Meridian PA-46-500TP Airplane Maintenance Manual page 1124

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(e) When the pressure gauge on the recharge unit or in the aircraft reaches 1800 to 1850 psi,
close the pressure regulator valve on the recharge unit. Disconnect the filler hose from the
filler valve and replace the protective cap on the filler valve. Check the cylinder pressure
according to Chart 3 after the cylinder temperature stabilizes.
(f) After detaching the service cart, cap hose and fittings to prevent contamination.
(g) Perform a leak check of the high pressure lines and clean off solution afterwards. If
solution is not properly cleaned off, corrosion may result.
35-10-00
PAGE 8
Apr 15/07
PIPER AIRCRAFT, INC.
PA-46-500TP, MALIBU MERIDIAN
MAINTENANCE MANUAL
When using a recharge unit consisting of two or more supply cylinders (cascade
storage system), it is recommended that the following procedure be used:
a Before opening any valves, check the pressure remaining in the airplane's
oxygen cylinder. If it is still partly charged, note the pressure indicated on the
cylinder gauge. Then open and close each valve on the cascade storage system
and determine which cylinder has the lowest pressure. When found, if this
cylinder has a pressure lower than the oxygen cylinder in the aircraft, do not
attempt using it for filling; use the storage cylinder that has a pressure higher
than the aircraft's cylinder but lower than the others.
b Open the valve on only the one storage cylinder with the lowest pressure. When
the pressures indicated on the aircraft's oxygen gauge and on the charging
stand gauge have equalized, close the valve of the storage cylinder, then go to
the storage cylinder with the next higher pressure and repeat the procedure.
c If after using the last storage cylinder the aircraft's oxygen system is still not fully
charged, a full storage cylinder should be put in place of a cylinder with the
lowest pressure and used in the same manner.
d A good amount of oxygen will remain in the large cylinders used in the cascade
system after filling only one of the cylinders. This remaining oxygen will be at a
pressure something less than the 1850 psi. This is not sufficient pressure to
completely refill another aircraft cylinder, although it will refill several small
cylinders.
e It is not economical, even on a three or four cylinder cascade system, to begin
recharging with oxygen at less than 300 psi pressure in the 300 cubic foot bank
of cylinders. So use 300 cubic foot cylinders down to approximately 300 psi;
then return for refilling. In two cylinder systems use to approximately 100 psi;
then return for filling.
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