Actuators with safety function (AMV 13, AMV 23 or AMV 33) and actuators without safety function (AMV 10, AMV 20 or AMV 30) are mainly used with VS, VM, VB, AVQM and VMV (only with AMV 10) valves. Safety version is activated automatically in case of power failure or if the power supply is switched off by the safety thermostat. Actuators automatically adapt stroke to valve end positions which reduces commissioning time.