Fire activated cooling fluid valve

A fuel supply system comprising:

• a fuel pump configured to supply fuel to a combustor in a gas turbine engine, said fuel pump also delivering fuel to at least one actuator as a hydraulic fluid, and said fuel pump also supplying fuel as a cooling fluid to said actuator, a valve selectively blocking or allowing the cooling fuel to pass to said actuator;
• said actuator having an actuator housing, having an outer surface, a cooling fluid valve for selectively providing cooling fluid to said actuator, said cooling fluid valve having an actuator portion extending outwardly beyond said outer surface of said housing;
• and
• said cooling fluid valve actuator portion including a plug force fit into an orifice in a valve housing, and said plug blocking flow of cooling fluid from a cooling fluid inlet to a cooling fluid outlet, said cooling fluid outlet being connected to communicate cooling fluid to the actuator, there being a flow window in said valve housing for communicating cooling fluid, and said plug blocking said flow window in a force fit position and said plug being formed of a material having a first coefficient of thermal expansion, and a portion of said valve housing including said orifice receiving said plug being formed of a material having a second coefficient of thermal expansion with said second coefficient of thermal expansion being higher than said first coefficient of thermal expansion such that when said actuator portion of said valve is exposed to sufficient heat, said force fit may be eliminated as said valve housing expands at greater rate than said plug, such that said plug moves away from a position blocking said flow window;
• and
• said valve housing being formed as a distinct part from said actuator housing, said actuator housing having an outer surface, wherein said valve housing is mounted in said outer surface of said actuator housing, and said valve housing extending outwardly away from said outer surface such that said plug and said flow window are on an outer side of said outer surface and said cooling fluid inlet and said cooling fluid outlet are on an opposed side of said outer surface.