Patent ID: 8905059

Claim:
A system for controlling leakage of diesel fuel into a natural gas side of a dual fuel injector during low pressure natural gas conditions, the dual fuel injector also having a diesel fuel side, the system comprising: a natural gas line having a natural gas line pressure, the natural gas line fluidly communicating with the natural gas side of the dual fuel injector; a diesel fuel line having a diesel fuel line pressure, the diesel fuel line fluidly communicating with the diesel fuel side of the dual fuel injector; and a leakage control valve having an inlet fluidly communicating with the diesel fuel line, an outlet fluidly communicating with natural gas side of the dual fuel injector, and a valve member fluidly communicating with the natural gas line; wherein the valve member is movable between an open position in which the inlet fluidly communicates with the outlet to permit diesel fuel flow to the natural gas side of the dual fuel injector, and a closed position preventing fluid communication from the inlet to the outlet to prevent diesel fuel from flowing to the natural gas side of the dual fuel injector, the valve member being responsive to the natural gas line pressure so that, when the natural gas line pressure equals or drops below a predetermined level, the valve member automatically moves to the closed position, thereby preventing diesel fuel flow to the natural gas side of the dual fuel injector.