Many modern production systems use pneumatic process control for its ease of operation and suitability for applications in the pharmaceutical, water and food & beverage sectors. At the heart of the pneumatic equipment is the valve island.
Strategically positioned e-stop buttons are used to halt part or all of a process when necessary. The EVS (external valve shutdown) function enables individual modules to be switched off independently or a complete valve island to be switched off while the communications remain operational with the rest of the network. This ensures any feedback relating to a safety shutoff, such as the final position of a safety valve, is relayed to the central processor.
The safety shut-down is operated by a simple stop switch operating through a safety relay, meeting the requirements in relation to the machinery directive EN ISO 13849. This is supported by a separate power supply that allows fieldbus communications to also be tested independent of the process, offering increased flexibility.
A major development is the addition of explosion protection approval according to ATEX / IECEx Zone 2. This enables access to new applications in potentially explosive environments, which are commonly found in the pharmaceutical sector, distilleries and food processors that handle fine dusts or flours.
Bürkert’s integrated liquid crystal displays offer in-field status information and diagnostics. The latest improvements include switching time measurement and data logging for process valves. The data can be displayed on the valve island as well as being forwarded to the process controller. For example, if the switching time feedback for a process valve was slowing down, this may indicate that something is sticking; if it is speeding up, the seals may be wearing. In such cases, the information highlights the need for maintenance and further investigation.
An optional web server enables remote access to the valve island, improving maintenance reaction times and offering real time information on device status. At the same time, the integral digital pressure measurement provides information on the supply and can indicate situations of air starvation if multiple valves are operated at the same time.
Bürkert’s latest developments also include the ability to connect with devices and PLCs, widening the flexibility of connectivity even further.