The control head is part of Bürkert's Element series of control heads, digital positioners and process controllers for diaphragm, angle seat and globe valves and is suitable for the food/beverage and pharmaceutical industries. The 8681 is universally adaptable and can be combined with all commercially available valve types, such as butterfly valves, ball valves and single and double-seat valves. It is easy to clean, features time-tested IP protection and is made of chemical-resistant materials, making it suitable for use in hygienic applications. As a central unit it performs all pneumatic actuation, feedback and diagnostic functions and bus communication. Depending on the process valve, up to three pneumatic actuator chambers can be controlled separately. Compared with actuation by pilot valves in a central switch cabinet, having the control heads mounted directly on the actuator can improve planning, installation, start-up and maintenance due to the significant reduction of the required connections. The switching times for the process fittings and the consumption of control air are minimized by the short hoses between the pilot valve in the control head and the pneumatic actuator. The decentral automation concept allows a clearly structured and easy-to-monitor system design, which can increase operational reliability.
