With the actuator attachments VAOM, it is possible to extend stem actuated valves from the series VMEF. If an actuator attachment VAOM is screwed onto the corresponding stem actuated valve from the series VMEF, it creates a toggle lever valve.Toggle lever valves can only be actuated by a cam from one side, only in one direction (forwards movement). If control is applied from the other direction (backwards movement), the valve is not actuated. The actuator attachment VAOM can also be used to replace mechanically worn actuators for toggle lever valves.