automatically once it has been started, In figure 2.1, the steam generator 
is the part numbered 2.
2.5. AIR COMPRESSOR
An air compressor, such as the one shown in figure 2.4, compresses the 
air used to operate much of the equipment on a diesel-electric locomotive.
Such  equipment  includes  airbrake  systems,  reversers,  electro-pneumatic
contactors, sanders, and window wipers.  The compressor may be engine driven 
flexible coupling to it.
The air compressor has a two-compression cycle.
Two
Figure 2.4.
Air Compressor.
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