Rotary actuators of this series are principally then suitable when program processes such as for instance acceleration - travel - brake are determined in controlled or regulated systems via proportional, respectively servo-valves. The rotary actuators of this series also often lend themselves in combination with simple hydraulic couplings when the inertial forces are low, e.g. to open and close draining systems, to actuate valves, to deposit and remove workpieces, to pivot load handling attachments and much more.