The Type 8691 control head is designed for the decentralized automation of ELEMENT Type 21xx pneumatic process valves. The valve position is detected by a contactless, analog sensor element, which automatically detects and stores the valve end positions during commissioning by means of a teach function. The integrated pilot valve controls single- or double-acting actuators. An AS-Interface, IO-Link or büS communication interface (based on CANopen) can be selected as an option. The design of the control head and actuator enables internal control air ducting without external hoses. In addition to the electrical position feedback, the device status on the control head itself is clearly recognizable by colored high-performance LEDs, even under difficult environmental conditions. The housing made of chemically resistant materials is easy to clean and offers practical IP protection for use in hygienic process technology in the food, beverage and pharmaceutical industries. Especially for system cleaning, the IP protection of the housing is supported by an overpressure in the control head. In combination with Bürkert drives of the ELEMENT series, the pneumatic actuator system enables spring chamber ventilation, which prevents contamination of the drive chambers by the environment.
