A fuel supply device for a liquefied petroleum direct injection (LPDI) engine in which liquefied petroleum gas (LPG) is directly injected into a combustion chamber and a start control method of an LPDI engine having the fuel supply device, wherein the high pressure fuel pump receives and compresses fuel to a pressure higher than a pressure at which fuel has been supplied, wherein the high pressure fuel rail buffers and supplies fuel to a direct injector that injects fuel directly into a combustion chamber, wherein the return line is connected to the supply line through the high pressure fuel pump to form a low pressure line, allowing a surplus portion of fuel supplied to the high pressure fuel pump from the fuel tank to return to the fuel tank, and wherein a first valve is disposed on the return line to control the flow rate of returning fuel.

A priming pump may include a housing; an inlet passageway inside of the housing; an outlet passageway inside of the housing; a divider, inside of the housing, separating the inlet passageway and the outlet passageway; a connecting passageway through the divider in fluid communication with the inlet passageway and the outlet passageway; a valve, disposed in the connecting passageway, configured for one-way fluid flow from the inlet passageway to the outlet passageway; a rotary pump, inside of the housing, having an inlet in fluid communication with the inlet passageway and an outlet in fluid communication with the outlet passageway; and a shaft connected to the rotary pump and extending through the housing, the shaft configured for rotation by an external driving mechanism.

There is provided a valve device including: a housing in which a valve chamber is provided on a lower side and a ventilation chamber is provided on an upper side via a partition wall, the partition wall being formed with a valve hole; a float valve; and a pressure adjusting valve. An accommodation portion is provided in a protruding manner from a surface of the partition wall. An accommodating space configured to accommodate the pressure adjusting valve is formed on an inner side of the accommodation portion, and an outer space is formed on an outer side of the accommodating space. The accommodation portion is formed with an opening through which the accommodating space and the outer space communicate with each other.

A fuel line check valve system and a fuel system that includes the fuel line diaphragm valve system are described. The fuel line diaphragm valve system may prevent flow into a fuel system that is generated via a vacuum in the fuel system. The fuel line diaphragm valve may also remain in an open state after it is open via a reduced pressure.

A remote fuel supply system comprising a fuel transfer unit for managing the flow of fuel from a remote fuel tank and onboard auxiliary tank to an engine. The system may include an engine unit comprising an onboard auxiliary tank, a remote fuel supply unit comprising a remote fuel tank, and a fuel transfer unit. The fuel transfer unit may include a housing featuring multiple inlets for receiving fresh fuel from the fuel supply unit and unburnt fuel from the engine unit, and the housing may include multiple outlets connected to diverter valves for selectively transferring fuel to the engine unit from the fuel supply sources; namely, the fresh fuel from the fuel supply unit and/or the unburnt fuel from the engine unit.

A fuel demand valve that opens with minimal engine suction pressure. The fuel demand valve has an inlet housing and an outlet housing with a valve door in the outlet housing that moves to allow flow through the valve when exposed to a pressure difference sufficient to overcome a spring internal to the outlet housing. The inlet housing includes a shelf, and two gaskets, one large and one small, are disposed between the shelf and the valve door such that they define different surface areas on the valve door. The different surface areas define the amount of force required to be exerted on the valve door for fuel to flow when exposed to fuel supply and engine suction pressures. The different surface areas provide a mechanical advantage whereby lower suction pressure from the engine exerts the same force as a higher fuel supply pressure on the valve door enabling lower fuel pressure operation.

A fuel pump system, comprising an inlet line and a motorized pump, a first selector valve in fluid communication with an inlet line at a first inlet port and in fluid communication with the motorized pump outlet via a first outlet branch at a second inlet port to receive fuel from the motorized pump outlet. The system can also include a main fuel pump in fluid communication with the first selector valve and a second selector valve, wherein the second selector valve can be in fluid communication with the main fuel pump and in fluid communication with the motorized pump outlet.

Systems and methods for supplying primary fuel and secondary fuel to an internal combustion engine may include supplying a first amount of the primary fuel and a second amount of the secondary fuel to the internal combustion engine. The system may include a first manifold to provide primary fuel to the internal combustion engine, and a primary valve associated with the first manifold to provide fluid flow between a primary fuel source and the internal combustion engine. A second manifold may provide secondary fuel to the internal combustion engine, and a fuel pump and/or a secondary valve may provide fluid flow between a secondary fuel source and the internal combustion engine. A controller may determine a total power load, the first amount of primary fuel, and the second amount of secondary fuel to supply to the internal combustion engine to meet the total power load.

Electronic fuel injection control system for an internal combustion engine, the internal combustion engine being equipped with at least one fuel feeding line provided with a fuel tank, at least one throttle valve, at least one injector, at least one fuel pump, at least one fuel return line having at least one solenoid valve, at least one first fuel return duct that connects the injector to the solenoid valve, at least one overpressure valve, at least one second return conduit adapted to connect the overpressure valve and the solenoid valve with the tank, wherein the fuel return line is provided with at least one calibrator allowing at least the state of said fuel pump and relative performances thereof to be verified.

Systems and methods for supplying primary fuel and secondary fuel to an internal combustion engine may include supplying a first amount of the primary fuel and a second amount of the secondary fuel to the internal combustion engine. The system may include a first manifold to provide primary fuel to the internal combustion engine, and a primary valve associated with the first manifold to provide fluid flow between a primary fuel source and the internal combustion engine. A second manifold may provide secondary fuel to the internal combustion engine, and a fuel pump and/or a secondary valve may provide fluid flow between a secondary fuel source and the internal combustion engine. A controller may determine a total power load, the first amount of primary fuel, and the second amount of secondary fuel to supply to the internal combustion engine to meet the total power load.