Patent ID: 8720482
Filing Date: 2014-05-13
Classification: F02C,Y10T

Abstract:
1. A fuel metering unit (FMU) comprising a metering valve having a metering valve member, further comprising a pressure raising valve (PRV) which has a delivery chamber to which the metering valve controls a supply of fuel, the PRV including a PRV valve member movable under the influence of the pressure within the delivery chamber between a closed position and an open position in which fuel is able to flow from the delivery chamber to an outlet port, and a push piston movable under the influence of the pressure within a control chamber to urge the PRY valve member towards its open position, wherein the control chamber communicates with a valve control port, such that the pressure within the control chamber is dependent, in part, upon whether the valve control port is open or closed, wherein the valve control port is provided on the metering valve, the valve control port being closable by the metering valve member and being arranged to be open when the metering valve occupies an engine start zero fuel flow delivery position.