Bürkert has expanded its line of digital electropneumatic positioners for pneumatic actuators with the SideControl 8791 Basic; the new version, which has no display, is designed for universal applications at an excellent cost-performance ratio.

The new 8791 positioner is the basic version of the Sidecontrol 8792 and 8793 positioners introduced in April 2009 and is specially designed for ease of operation. Yet the Sidecontrol 8791 features the same reliable electropneumatic positioning system for excellent control accuracy and dynamics. As it can be mounted in various different ways to linear and rotary actuators according to IEC534-6 and VDI/VDE 3845 (Namur) as well as to Bürkert process valves, the 8791 is extremely flexible and suitable for a wide range of applications. This positioner is also ideal for use in harsh environments due to its compact, sturdy aluminium housing with protection class IP65/67.

Reliable And User-friendly
Since there is no display and the software has been simplified, the 8791 positioner is a good alternative for applications where no further configuration on site is neither necessary nor desired. The only controls on the device are used to call up preset values. Other parameters for the positioner can be configured from a PC connected via the RS232 interface, using PACTware.

For Universal Applications
The Sidecontrol 8791 from Bürkert uses 3-wire technology. This makes the controller much less expensive than a comparable device based on 2-wire technology; nevertheless, it is approved for ATEX zones 2/22. A further cost benefit to the user is the smaller number of versions required. The Bürkert positioner can be used as the sole positioning system for the entire compressed air supply, directly from the network and without costly pressure reduction. The 8791 offers one solution for both single and double acting actuator systems. This allows customers to reduce their stock of controllers to a minimum. The positioning system features an impressive control air pressure range of 1.4 to 7 bar and a high air power range of 7 to 100 l/min (150 l/min at 6 bar). When fully regulated, no control air is consumed.

Facts And Data
• Setpoint value via norm signal 0/4-20 mA
• Analog position feedback (4-20 mA)
• Binary input with parameterizable function
• Control of basic functions via internal DIP switches and buttons
• Configuration and parameterization of additional functions via PC tool
• Valve end position detection by discrete inductive proximity switches
• Mechanical position indication
• Single and double acting version in one unit
• Control air pressure 1.4 to 7 bar
• Operating voltage 24VDC +/- 10%
• RS232 port for communication and parameterization