Fuel cell system, gas tank device and shut-off valve for a gas tank device

A shut-off valve (100) for a gas tank device (200), comprising:

• a housing (1) which has an inlet opening (11) for connecting to a high-pressure tank (210), an outlet opening (12) for connecting to a supply line (302) and a control opening (13) for connecting to the supply line (302), wherein the housing (1) defines an inner space (10) extending along a longitudinal axis (L1) and has a partition (14) which, with respect to the longitudinal axis (L1), divides the interior space (10) into an outlet chamber (10A) and a control chamber (10B), wherein the partition (14) has a guide hole (15) which extends between the outlet chamber (10A) and the control chamber (10B);
• an electrical coil (2) which is accommodated in the partition (14) and surrounds the guide hole (15);
• a servo valve needle (3) which is arranged in the control chamber (10B), is preloaded along the longitudinal axis (L1) into a closed position in which the servo valve needle (3) seals the control opening (13) and can be moved by a magnetic field which can be generated by the coil (2), into an open position in which the servo valve needle (3) exposes the control opening (13) and abuts the partition (14), wherein the servo valve needle (3) has a connecting channel (33) which connects the control chamber (10B) to the guide hole (15) in the open position of the servo valve needle (3);
• and
• a main valve needle (4) which is movably guided in the guide hole (15) along the longitudinal axis (L1), is preloaded along the longitudinal axis (L1) into a closed position in which the main valve needle (4) seals the outlet opening (12), and, when the servo valve needle (3) is arranged in its open position, can be moved by the magnetic field which can be generated by the coil (2), into an open position in which the main valve needle (4) exposes the outlet opening (12).