AMV or AME are designations that describe how the actuator is controlled. AMV means that the actuator is either 2-point or 3-point controlled, AME means that the actuator has modulating control. This is a very important difference since not every type of control is appropriate for every application.
Modulating, or AME actuators, are appropriate for precise regulation of the flow as they also have feedback signal and can position themselves very precisely in accordance to the signal from the controller. Furthermore, AME (sometimes also called the electronic version of actuators) actuators provide more features on DIP switches and provide much more flexibility and control variations for the customer.
AMV actuators usually by default have no active return signal, unless there is a potentiometer used inside, and are not so precise when it comes to the flow control, but still offer a very good solution for customer requirements.