Do not charge this system with oxygen or
replacing components on the nitrogen servicing unit.
interchange components with oxygen
As noted earlier, the charts in this manual do not cover
c o m p o n e n t s . To d o s o m a y p r o d u c e a n
all of the possible problems you may encounter. For
explosion.
complete coverage of troubleshooting, consult the
appropriate service manuals.
Because of the oil contamination that may be
contained in nitrogen servicing units, do not use
Safety
them for purging oxygen systems. For that
The following precautions must be observed
purpose, use the Aircraft Liquid Oxygen System
during operation and maintenance of nitrogen
Gas Purging Set, Part Number 900001-1.
servicing units.
Never back out on the regulator to relieve
Never use your hands to feel for leaks in
pressure until the hose valve has been secured.
high-pressure nitrogen components or
Always check the hydrostatic test dates of the
plumbing. An invisible, high-pressure leak can
nitrogen cylinders to ensure that they have not
act like a sharp knife and penetrate the skin or
been in service for more than 5 years.
even sever a finger.
Never stretch a servicing line to reach a
Safety chains are provided at the front of the
connection. Position the trailer so that the
nitrogen servicing unit and are to be used for
servicing line is not under tension.
breakaway only, not for towing the trailer.
Never service a system without using an
Only licensed, qualified operators should
approved remote inflator between the hose and
operate the nitrogen servicing unit.
the system being serviced. Ensure that the
Do not allow oil, grease, or readily combustible
remote inflator is within its calibration cycle.
materials to come in contact with cylinders,
Before disconnecting the servicing line from a
valves, regulators, gauges, or fittings.
fitting, bleed the line by turning the servicing
Inspect the servicing hose and fittings of the
line valve to the BLEED position.
system to be charged before servicing. Carefully
In locations where inside storage space is
remove any traces of oil, grease, or
available, stow the servicing trailer inside. When
inside storage is impractical, fabricate a canvas
Always bleed the servicing line to ensure that it
cover to protect the manifold, panel, and
is free of all foreign matter before connecting it
component assemblies. Properly stow the
to the system to be charged.
servicing line in the stowage box.
Open all valves slowly. Adjust the pressure
Nitrogen should not be discharged in large
regulator in small increments. Avoid the danger
quantities into closed compartments unless
of rapid charging.
adequate ventilation is provided.
Open the manifold bypass valve only when
When moving the trailer from place to place,
recharging cylinders or when air drive is being
close the cylinder valves, stow the servicing line,
used.
and release the hand brake.
Before commencing a servicing operation,
determine the pressure of the system to be
LOW-PRESSURE AIR COMPRESSORS
charged.
Low-pressure air from ships' compressors or
Because of the dangerously high pressures used,
shop-installed compressors is the most common
do not, under any circumstances, substitute any
s o u r c e o f c o m p r e s s e d a i r i n t h e wo r k c e n t e r.
components of this system with those of other
Compressed air is used to dry parts, run pneumatic
systems. This includes the stainless steel fittings
tools, service low-pressure tires, and even drive
used throughout the plumbing.
pneumatic-powered support equipment, such as
Do not use high-pressure nitrogen to power
hydraulic check and fill stands, dry honing machines,
low-pressure pneumatic tools or support
floor jacks, and paint sprayers. Remember that when
equipment.
an air separator is not in use, compressed air normally
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