The control head Type 8691 is designed for decentralized automation of ELEMENT Type 21xx pneumatic process valves. The registration of the valve position is done through a contact-free analogue sensor element, which automatically recognises and saves the valve end position through the Teach function during start-up. The integrated pilot valve controls single or double-acting actuators. As an option a communication interface, AS-Interface, DeviceNet, IO-Link or büS (based on CANopen) can be chosen. The design of the control head and the actuator enables an internal control air routing without external tubings. Besides the electrical position feedback, the status of the device is shown directly on the control head itself through coloured powerful LEDs, even in difficult ambient conditions. 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.