A control valve of a fuel injector

The present invention relates to a control valve (113; 113') for a fuel injector (101). The control valve (113; 113') has a control valve body (115; 115') which defines a supply passage (133; 133') for high pressure fuel. A control chamber (119; 119') and a pressure compensating chamber (143; 143') are provided in the control valve (113; 113'). The control chamber (119; 119') and the pressure compensating chamber (143; 143') are both in fluid communication with the supply passage (133; 133'). A control valve member (117; 117') is provided for controlling fuel pressure in the control chamber (119; 119'). The pressure compensating chamber (143; 143') is spaced radially outwardly from the control chamber (119; 119'). The invention also relates to a control valve member (117') having a pressure compensating cavity (159).