always be properly secured. Do not handle
GASEOUS OXYGEN SYSTEMS
cylinders or any other oxygen equipment with
LEARNING OBJECTIVE: Identify safety
greasy hands, gloves, or other greasy materials.
precautions, components, and maintenance
The storage area should be located so that oil or
procedures for gaseous oxygen systems.
grease from other equipment cannot be
Gaseous oxygen systems are used primarily in
accidentally splashed or spilled on the cylinders.
large, multi-place aircraft where space and weight
Additional safety precautions may be found in the
limitation are less important items and the systems are
publications of technical manual NAVAIROSH
used only occasionally.
Requirements for the Shore Establishments, NAVAIR
A1-NAOSH-SAF-000/P-5100; Aviators Breathing
Oxygen (ABO) Surveillance Program Laboratory
Manual and Field Guide, A6-3332AO-GYD-000; and
The pressure in gaseous oxygen supply cylinders
Aviator Crew Systems Technical Manuals, NAVAIR
should not be allowed to fall below 50 pounds per
square inch (psi). If the pressure falls much below this
value, moisture is likely to accumulate in the cylinder
and could be introduced into the oxygen system of the
aircraft, causing component malfunction.
Basically, all gaseous oxygen systems consist of
All oxygen under pressure is potentially very
dangerous if handled carelessly. Personnel servicing or
· Containers (cylinders) for storing oxygen supply
maintaining oxygen systems and components must be
· Tubing to route the oxygen from the main supply
extremely careful about preventing grease, oil,
hydraulic fluid, or similar hydrocarbons as well as other
to the users
· Various valves for directing the oxygen through
hoses, fittings, and equipment, as this contact presents a
the proper tubing
fire and explosion hazard.
· Metering devices (regulators) to control the flow
If, because of hydraulic leaks or some other
of oxygen to the user
unpreventable malfunction, components of the oxygen
system do become externally contaminated, they
· Gauges for indicating the oxygen pressure
should be cleaned using only approved oxygen system
· Masks to direct the oxygen to each user's
cleaning compounds. While some MIMs specify the
use of a variety of cleaning compounds, the preferred
compound is oxygen system cleaning compound type I
conforming to Military Specification MIL-C-81302.
The following safety precautions should be
craft systems are generally high-pressure and
non-shatterable, meaning that the cylinder is designed
· Under no circumstances should a non-approved
to resist shattering when punctured by a foreign object,
cleaning compound be used on any oxygen
such as gunfire, at a pressure of 1,800 psi. The
lines, fittings, or components.
resistance to shattering is generally achieved by the use
· When handling oxygen cylinders, the valve
of a heat-treated alloy or wire wrapping applied to the
protection cap should always be in place. Before
outside of the cylinder. The two most common cylinder
removing the cap and opening the valve, ensure
sizes are 514 and 295 cubic inches.
that the cylinder is firmly supported. A broken
The main advantage of the high-pressure cylinder
valve may cause a pressurized cylinder to be
is that it minimizes space used for storing gaseous
propelled like a rocket.
oxygen. All high-pressure oxygen cylinders are painted
· Do NOT use oxygen in systems intended for
green in accordance with the established color codes
other gases or as a substitute for compressed air.
provided in MIL-STD-101A.
· Cylinders being stored for use on gaseous
Cylinders come equipped with either a manually
oxygen servicing trailers or any other use must
operated handwheel valve or an automatic self-opening