Figure 7-44.—Air cylinder.
cylindrical or spherical in shape. Both types of
cylinders are made up of two main parts—the
container itself and a manifold assembly. The
container serves as a trap for moisture, as well as an
air storage space. The manifold assembly is made up
of the “in” and “outlet” ports and a moisture drain
fitting. See figure 7-44.
Cooling of the high-pressure air in the storage
cylinders will cause some condensation to collect in
them. To ensure positive operation of systems,
storage cylinders must be purged of moisture
periodically. This is accomplished by slightly
cracking the moisture drain fitting, located on the
cylinder manifold.
Some aircraft have a pneumatic system that will
maintain the required pressure in these bottles in
flight. However, most of these pneumatic systems
require servicing on the ground with an external
source of high-pressure air or nitrogen prior to each
flight.
Air storage bottles are serviced in the same
manner as accumulators. Most air bottles have an air
filler valve and a pressure gauge. These systems
generally require higher servicing pressure than
accumulators.
Since gases expand with heat and contract when
cooled, air storage bottles are usually filled to a given
pressure at ambient temperature. A graph similar to
that shown in figure 7-45 is usually mounted on a
Figure 7-45.—Pneumatic storage cylinder inflation chart.
7-45
