Patent ID: 7607285

Claim:
A thermal recirculation throttle valve for an aircraft fuel system, the thermal recirculation throttle valve comprising: a housing having a throttling valve chamber, an inlet, a first outlet, and a second outlet; a power piston disposed within the housing for translational movement therein; and a throttling valve mounted to the power piston and configured to move therewith between: (i) a fuel shut-off position wherein the throttling valve substantially blocks fuel flow from the inlet to the first outlet and substantially permits fuel flow from the throttling valve chamber to the second outlet, (ii) a fully open operating position wherein the throttling valve substantially permits fuel flow from the inlet to the first outlet and substantially blocks fuel flow from the throttling valve chamber to the second outlet, (iii) a failsafe extended position wherein the throttling valve permits a predetermined flow from the inlet to the first outlet, and (iv) a failsafe retracted position wherein the throttling valve permits a predetermined flow from the inlet to the first outlet; wherein the fuel shut-off position resides between the failsafe extended position and the fully open operating position, and wherein the fully open operating position resides between the failsafe retracted position and fuel shut-off position; and wherein the thermal recirculation throttle valve further comprises means for preventing the throttling valve from extending beyond the failsafe extended position, and means for preventing the throttling valve from retracting beyond the failsafe retracted position.