Oxygen System Description And Operation - Piper PA-44-180 SEMINOLE Maintenance Manual

GENERAL.
The purpose of this chapter is to give supplemental information for the servicing of the oxygen systems.
Major repairs to the system and cylinder should be accomplished by an approved shop.
When refilling any oxygen cylinder make sure to use only aviation breathing oxygen as specified in
MIL-0-27210C. The moisture content of aviation breathing oxygen cannot exceed 0.005 milligrams of water
vapor per filter of gas at a temperature of 70° F and a pressure of 29.92 inches of mercury.
DESCRIPTION AND OPERATION. (Refer to Figures 35-1 and 35-2.)
A fixed and/or portable oxygen system is available for the 180T aircraft. Scott Aviation manufactures the
major components for these systems and should be contacted along with Piper Customer services for any further
information not covered herein. For specific parts information refer to the Piper Parts Catalog.
The fixed oxygen system involves a 48.3 cu. ft. cylinder tied into four overhead "shallow wall" outlets, and a
"push pull" regulator-control mechanism. A 3AA 1800 tank, mounted in the modified tailcone behind the
baggage compartment, is connected to an external fill valve mounted to the fuselage behind fuselage station
bulkhead 191.0. The manifold for the outlets is set up such that the main feed line for the overhead outlets, is
connected to the left rear passenger outlet from which the right rear and pilot outlets are connected. The copilot
outlet is connected to the right rear passenger outlet. Push-pull control is provided by a knob on the overhead
panel, to the left of the fresh air duct control. A gauge for displaying tank pressure is mounted in the overhead
duct behind the passengers and is lighted by a post light.
The portable oxygen system uses a 22 cu. ft. capacity, 3AA1800 cylinder. The tank is incorporated in a
carrying case which utilizes a dual manifold, permitting four masks to be used with dual connectors at each
outlet. The portable unit fits in a cradle between the back passenger seats.
Refer to pilot operating handbook for operating instructions.
DO NOT USE GREASE OR ANY TYPE OF GREASE FITTING ON ANY
H A R D WARE CONNECTED TO THE OXYGEN SYSTEM. WHEN WORKING
WITH AN OXYGEN SYSTEM MAKE SURE HANDS, CLOTHING, TO O L S ,
AND THE IMMEDIATE AREA ARE FREE OF GREASE.
Oxygen cylinders are identified by the ICC or DOT identification stamped on the
c y l i n d e r. The standard weight cylinder (ICC or D0T 3AA1800) must be
hydrostatically tested every 5 years. The month and year of the last test is stamped
beneath the ICC, DOT identification.
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
— WARNING —
— Note —
2J9
3 5 - 0 1 - 0 0
Page 35-01
Revised: May 15, 1989