EGR valve for a turbocharged diesel engine

An EGR valve for a turbocharged diesel engine has valve having a valve closure member (12) movable relative to a mating surface (14) for regulating the flow of EGR gases and a first actuator (16) for enabling the position of the valve closure member (12) to be varied continuously. A second actuator (18) is provided to close the valve fully regardless of the position of the first actuator (16), so as to enable the EGR flow to be reduced more rapidly than can be achieved by said first actuator alone.