Figure 7-26.--HPAC, cross-sectional views.
in line. The first stage is in the center, the second
During operation, ambient air is drawn
stage is at the motor end, and the third stage is
into the first-stage cylinder through the in-
outboard. The fourth stage is mounted above the
let filter and inlet valves. The first stage
second stage, and the fifth stage is above the third
is double acting, and air is drawn into the
stage. The fourth- and fifth-stage pistons are
lower cylinder area as the piston is moving
tandem mounted to the second- and third-stage
upward. At the same time, air in the upper
pistons, respectively.
cylinder is being compressed and forced out
7-23
