HYDRAMECHANICAL PROTECTIVE SYSTEM
SCHEMATIC NO. 7 (HIGH ENGINE COOLANT TEMPERATURE FAULT)
1. Selector valve. 2. Low speed oil protection valve. 4. Diverter valve orifice. 7. Diverter valve. 8. Fuel shutoff
actuator. 9. Thermostatic pilot valve. 10. High speed oil protection valve. 15. Fuel shutoff sequence valve.
HIGH ENGINE COOLANT TEMPERATURE
CIRCUIT (FAULT CONDITION)
Make Reference to Schematic No. 7
When engine coolant temperature increases to
99C (2100F), thermostatic pilot valve (9) will
open. This will let engine oil in the circuit drain
and cause a decrease in oil pressure on low
speed oil protection valve (2) and high speed oil
protection valve (10). Valves (2) and (10) will
close and stop oil flow from diverter valve (7).
The difference in oil pressure across diverter
valve orifice (4) will now go to zero. The valve
spool of diverter valve (7) will move down by
spring force, which will cause alignment of the
ports to fuel shutoff actuator (8). The actuator
now causes the governor to move the fuel
control linkage to the "SHUTOFF" position and
shutdown the engine.