FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 9. Aircraft Systems and Components | 3. Emergency Equipment | 9-51. Service Oxygen Cylinders
AC 43.13-1B CHG 1
9/27/01
(1) Inspection. Do not attempt to
charge oxygen cylinders if any of the following
discrepancies exist:
(a) Inspect for contaminated fittings
on the manifold, cylinder, or outside filler
valve. If cleaning is needed, wipe with stabi-
lized trichlorethylene and let air dry. Do not
permit the solvent to enter any internal parts.
Continue this procedure until the cylinder has
been charged in accordance with table 9-5.
(e) Close all valves on the manifold
system.
(f) Close the valve on the filled cyl-
inder and remove the cylinder from the mani-
fold.
(b) Check the hydrostatic test date of
the cylinder. DOT regulations require ICC or
DOT 3AA 1800 designation cylinders to be
hydrostatic tested to 5/3 their working pres-
sure, every 5 years (10 years if they meet the
requirements in 49 CFR 173.34,e, 16).
Cylinders bearing designation ICC or
DOT 3HT 1850 (Ref. 49 CFR 173.34,e, 15)
must be hydrostatic tested to 5/3 their working
pressure every 3 years, and retired from service
24 years or 4,380 filling cycles after the date of
manufacture, whichever occurs first.
(c) If the cylinder is completely
empty, do not charge. An empty cylinder must
be removed, inspected, and cleaned before
charging.
(2) Charging.
(a) Connect the cylinder valve outlet
or the outside filler valve to the manifold.
(b) Slowly open the valve of the
cylinder to be charged and observe the pres-
sure on the gauge of the manifold system.
(c) Slowly open the valve of the cyl-
inder on the manifold system having the low-
est pressure and allow the pressure to equalize.
(d) Close the cylinder valve on the
manifold system and slowly open the valve of
the cylinder having the next highest pressure.
(g) Using a leak detector, test for
leakage around the cylinder valve threaded
connections. (If leakage is present, discharge
the oxygen and return the cylinder to the facil-
ity for repair.)
(h) Let the cylinder stabilize for a pe-
riod of at least 1 hour, and then recheck the
pressure.
(i) Make any necessary adjustments
in the pressure.
b. Charging of Low-Pressure Oxygen
Systems and Portables. For recharging a
low-pressure aircraft oxygen system, or port-
able cylinders, it is essential that the oxygen
trailer or cart have a pressure-reducing regu-
lator. Military types E-2 or C-1 reducing
regulators are satisfactory. These types of
regulators reduce the large cylinder pressure
from 2,000 psi to a line pressure of 450 psi.
(A welding pressure-reducing regulator is not
satisfactory.)
CAUTION: When refilling the low-
pressure system or portable cylinders,
open the oxygen filler tank valve
slowly to allow the system or portable
cylinders to be filled at a slow rate.
After the refilling operation is com-
pleted, check for leaks with a leak de-
tector. If a leak is detected, para-
graph 9-49b(2)(d) should be referred
to for corrective action.
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