Patent ID: 8230841
Filing Date: 2012-07-31
Classification: F02M

Abstract:
1. A vehicle fuel system comprising: a fuel line that supplies fuel to an engine at a fuel line pressure; a first fuel pump having an exit port and a first fuel pump check valve, the first fuel pump supplies fuel through the exit port and the first fuel pump check valve to the fuel line at a first pressure; a first pressure regulator that regulates the first pressure of fuel supplied by the first fuel pump; a second fuel pump that supplies fuel to the fuel line; a second pressure regulator that regulates a second pressure of fuel supplied by the second fuel pump, the second pressure greater than the first pressure; a flow check valve with a flow check valve inlet in communication with the exit port of the first fuel pump and a flow check valve outlet in communication with the fuel line, the flow check valve open and close position governed by a flow check valve open pressure setting, pressure at the flow check valve inlet, and pressure at the flow check valve outlet, the flow check valve is closed when a pressure at the flow check valve outlet is greater than the pressure at the flow check valve inlet; wherein the flow check valve inlet pressure is greater than the sum of the flow check valve outlet pressure and the flow check valve open pressure setting; and fuel from the first fuel pump en route to the fuel line flows through the flow check valve.