Woodward TG-10E, Installation And Operation Manual

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Manual 04045 TG-10E/-13E/-17E Actuator
Woodward 25
The control port in the pilot-valve bushing (7) is covered by the land on the pilot-
valve plunger (20). This stops the power piston (6) and the actuator terminal
shaft (2) in the new position needed to run the turbine at the decreased load or
decreased-speed setting.
Figure 5-1. TG Actuator Schematic Diagram
Increase in Load or Speed Setting
Assume that the turbine is running on-speed under steady-state conditions. The
control voltage to the actuator is therefore constant. The pilot-valve plunger (20)
is centered over the control port of the pilot-valve bushing (7) and the control
land stops the flow of pressure oil through the bushing control port. There is no
movement of the power piston (6) and no movement of the actuator terminal
shaft (2).