CONTROL VALVE

The present disclosure relates to a fuel injector (101, 201) for injecting fuel into a combustion chamber of an internal combustion engine. The fuel injector (101, 201) comprises a control chamber (105) for controlling a needle valve. A control valve assembly (103) is provided for controlling fuel pressure within the control chamber (105). A fuel return line (127) is provided for returning fuel from the control valve assembly (103). The control valve assembly (103) has a control valve (119) and a valve seat (121). The control valve (119) is movable between a closed position in which fluid communication is inhibited between the control chamber (105) and the fuel return line (127) and an open position in which fluid communication is enabled between the control chamber (105) and the fuel return line (127). A fuel flow restriction (151, 251) is provided downstream of the valve seat (121) for maintaining the fuel pressure in a region between the valve seat (121) and the fuel flow restriction (151, 251) above a return pressure of fuel in the fuel return line (127). The present disclosure also relates to a control valve assembly (103) for a fuel injector (101, 201).