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

Claim 14:
15. A fuel system, comprising:
two independent electric shutoff systems configured to control a selection and shutoff valve (SSOV), wherein the two electric shutoff systems are configured to control three valves to perform five functions,
wherein at least one function of the five functions includes, in a first state of a first valve of the three valves;
allowing a primary flow having a primary flow pressure to pass therethrough such that the primary flow can travel to an output line;
communicating a secondary flow source input of the first valve of the three valves to a secondary flow destination output of the first valve of the three valves to allow a secondary flow to flow from a secondary flow source to a secondary flow destination; and
preventing fluid communication between a low pressure port of the first valve of the three valves and a bypass valve port of the first valve of the three valves in fluid communication with a second valve of the three valves via a bypass line;

wherein at least one function of the five functions includes, in a second state of the first valve of the three valves;
shutting off the primary flow to prevent the primary flow from travelling to the output line,
allowing the secondary flow from the secondary flow source to pass therethrough such that the secondary flow can travel to the output line; and
communicating the low pressure port to the bypass valve port to communicate a low pressure to the second valve of the three valves;

wherein, the first valve of the three valves includes a back pressure port configured to be in fluid communication with a back pressure line such that a back pressure acts on the first valve of the three valves to bias the first valve of the three valves toward the second state such that when the back pressure exceeds a primary flow pressure of the primary flow, the first valve of the three valves moves to the second state.