the probable cause in the second and the remedy
in the third. The list of probable causes is arranged
in the order of probability of occurrence.
Some manufacturer’s troubleshooting charts
or aids may include several sheets, similar to the
one illustrated in table 4-2, This sheet gives a step-
by-step method to correct known malfunctions.
Notice how each step progresses through the
system. At each step it indicates a correction
procedure; however, if the system checks OK at
that point, directions are given to proceed with
further logical troubleshooting. In almost all
cases, the steps of troubleshooting are arranged
to correspond with the steps of the operational
‘checkout procedures.
LIQUID OXYGEN (LOX) SYSTEMS
Learning Objective: Identify safety pre-
cautions, components, installation and
testing of components, and operating
procedures for liquid oxygen (LOX)
systems.
Liquid oxygen, commonly referred to as
LOX, is normally obtained by a combined
cooling and pressurization process. When
the temperature of gaseous oxygen is low-
ered to -182°F under 720 psi pressure.
it will begin to form into a liquid. When
the temperature is lowered to – 297°F, it
Table 4-2.—Oxygen System Troubleshooting
4-11
