Figure 4-7.-DD-963 start air system (simplified).
compare it with the following listing of the five valves
can see that the valve alignment for a GTG start or
and their positions, you will see the proper valve
motor should be same as for a GTM motor. The only
alignment for GTM LP starting and motoring.
exception is that it does not matter what position the
motor air regulating valve is in.
VALVE POSITION FOR:
HP and LP Starting. As we mentioned at the
beginning of this section, there are two methods of
starting--using either HP or LP air. Again, if you
interfaces with the start air system just before the
motor air regulating valve. Notice also in figure 4-7
HI TEMP BLEED
that the HP-to-LP air reducing valve pressure and
the orifice are configurations that only apply to DD-
MOTOR AIR REG
The CG-47 ships share this basic system design,
but the CG-47 HP/LP reducing station has a lower
outlet pressure (45 psig), which eliminates the need
Now that you have seen the valve alignment for
for the orifice pack. Because of the location at which
GTM LP starting and motoring, let's discuss the
the HP air enters the system, there is only one valve
valve alignment for GTG starting.
that must be aligned, the motor air regulator.