Abstract: A valve arrangement for a wellhead of a hydrocarbon well comprises a valve for mounting in a port of a wellhead, and an actuator device for actuating the valve to move to an open position. The actuator device comprises a housing having a through channel extending between a first end, at which the valve is mounted, and a second end. The housing comprises at least one first port that leads into the through channel. The actuator device further comprises an actuator rod that is movably arranged in the through channel and configured to open the valve by the actuator rod being movable between at least a first position and a second position, and a control device arranged to control the movement of the actuator rod.