Thermal management valve with drop-tight shutoff of return to tank

Abstract

A thermal management system for an aircraft fuel system includes a plurality of fuel pressure sources. A spool valve is fluidly connected to the pressure sources and is movable between a plurality of positions in response to the pressure sources. An oil cooler is fluidly connected to the spool valve with fuel flowing through the spool valve to the oil cooler in response to the spool valve being in one of the positions. The fuel tank is fluidly connected to the spool valve with fuel flowing to the spool valve to the fuel tank in response to the spool valve being in another of the positions. The spool valve moves to a closed fuel tank output position response to the pressure sources. The spool valve includes a housing having a bore with the plurality of pressure inputs and oil cooler and fuel tank outputs fluidly connected to the bore. A spool is disposed within the bore and is movable axially relative thereto between oil cooler, open fuel tank and the closed fuel tank outward positions. A valve assembly including a piston and target piston is disposed within the bore and is movable axially relative thereto. The valve assembly coacts with the spool to provide the closed fuel tank output position. A seal is arranged between the spool and the valve assembly sealing the spool and the valve assembly in the closed fuel tank output position to ensure that no fuel is permitted to leak back to the fuel tank.

Dependencies are inferred from the claim text.