Patent ID: 11859551
Assignee: HAMILTON SUNDSTRAND CORPORATION
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 13:
14. A fuel system configured to:
in a first mode:
direct a main pump flow to an engine;
direct the main pump flow to the engine via a primary flow output of a selection and shut off valve (SSOV);
direct a secondary flow source to a secondary flow destination output of the SSOV to allow a secondary flow to flow from the secondary flow source to a secondary flow destination; and
prevent fluid communication between a low pressure port of the SSOV and a bypass valve port of the SSOV in fluid communication with a bypass valve (WMBV) via a bypass line;

in a second mode:
shut off the main pump flow to prevent the main pump flow from travelling to the engine;
direct the secondary flow source to pass through the SSOV such that the secondary flow can travel to the engine; and
communicate the low pressure port to the bypass valve port to communicate a low pressure to the WMBV;

wherein, the SSOV includes a back pressure port configured to be in fluid communication with a back pressure line such that a back pressure acts on the SSOV to bias the SSOV toward the second mode such that when the back pressure exceeds a main pump flow pressure of the main pump flow, the SSOV moves to the second mode.