The pneumatic control unit Type 8690 is designed for decentralised automation of ELEMENT Type 21xx pneumatic process valves. Mechanical or inductive limit switches register the valve position. The integrated pilot valve controls single or double-acting actuators. The design of the control unit and the actuator enables an integrated pilot air duct without external tubings. Besides the electrical position feedback, the status of the device is shown directly on the pneumatic control unit itself. The housing is easy to clean and features proven IP protection and chemically resistant materials for use in hygienic processing, in food, beverage and pharmaceutical industries. Focused on wash down applications, the IP protection of the housing is supported by a positive pressure inside the control head. Combined with Bürkert ELEMENT actuators, the pneumatic actuating system enables spring chamber aeration that avoids actuator chamber contamination from the environment.