Type 8691 Control Head

The device key 8691 control head is designed for decentralised automation of ELEMENT Type 21xx pneumatic process valves. The valve position is registered via a contact-free, analogue sensor element which automatically detects and saves the valve end position using the Teach function during start-up. The integrated pilot valve controls single or double-acting actuators. An optional communication interface, AS-Interface, IO-Link or büS (based on CANopen) can be selected. The design of the control head and the actuator permits internal control air routing without external piping. Besides the electrical position feedback, the device status 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 the food, beverage and pharmaceutical industries. Focused on plant wash-down applications, the IP protection of the housing is supported by 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.

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