compressor. It is being installed aboard some of
screw-type compressor. Figure 7-21 shows the
our newer ships, such as the FFG-7 class ships.
general arrangement of the LPAC unit.
This low-pressure air compressor is a single-stage
Compression is caused by the meshing of two
positive-displacement, axial-flow, helical-screw
helical rotors (a male and a female rotor, as shown
type of compressor. It is often referred to as a
in fig. 7-22) located on parallel shafts and enclosed
Figure 7-21.--LPAC (screw type).
Figure 7-22.--LPAC, compressor section.
7-19