Accessories for swivel actuators – positionersPositioners enable the position of process valves actuated by pneumatic actuators to be easily and efficiently controlled. In general, a positioner converts an input signal into a corresponding setpoint position of the process valve. Depending on the type of input signal, pneumatic or electrical, a distinction is made between pneumatic or electropneumatic valve positioners. To use the positioners independently of the manufacturer, they are usually attached to pneumatic actuators in accordance with the industrial standards VDI/VDE 3845 (quarter turn actuators) or VDI/VDE 3847 and IEC 60534-6 (linear actuators). If this is not possible, the positioner can also be mounted on the actuator with manufacturer-specific mounting kits to provide position feedback.