The Forta range actuator does not fit onto the V321 Valve.
The actuator has a 10mm fitting, the valve (DN65 to DN100 only) spindle has a 8mm stem.
On V321 valves size DN65 to DN100 an adaptor piece is supplied with the valve part no. 880-0133-000 to adapt the valve spindle to the actuator drive.
The part no. 880-0133-000 can be ordered separately.