Control valve offers hygienic solution

The food and beverage industries present particular problems to designers, demanding as they do the highest possible standards of cleanliness. Rust, corrosion, dirt, flaking paint, water ingress and external integrity impaired by aggressive products, would all be high up on any list of typical application problems for valves in the food and beverage industries. Many would say that these industries have, for too long, been plagued by these problems, to the extent that companies have learned to live with them. With this in mind, a stainless steel, pneumatically-actuated control valve has been developed that will meet the challenges of such highly hygienic processes, while also satisfying the pressing industry need to reduce energy use. Thanks to intelligent internal design, the air consumption to actuate Element valves is up to 40% lower in comparison with conventional process valve systems. Designed to IP 65/67 protection class, the Element control valves from Burkert, with their heat and chemical resistant design, easily withstand the rinsing and cleaning processes required in food and beverage plants. The clean, sleek external lines ensure the valves are easy to clean and also stay cleaner for longer. The Element control valves offer a number of innovations. First, high-gloss polished valve stems minimise friction and maximise the service life of the automatic self-adjusting seals. Secondly, the valve stroke position feedback transducer is not only integrated within the valve, but is also contact-less, meaning it never blocks or wears out and always remains accurate because it measures the linear stroke motion directly without conversion. Thirdly, because the feedback transducer is fully protected inside the valve, the requirement for external linkages, nuts, bolts and connections is eliminated. This innovation dramatically reduces the areas where product can accumulate and cause contamination. Fourthly, the control air is also routed internally, without the need for awkward external hoses. A further innovation on the Element units is valve actuator control, which is achieved by means of the integrated pilot valves that can also be actuated manually for easy local operation. For each operation, clean and dry control air is deliberately flushed into all areas of the actuator. This ensures that, unlike traditional solutions, ambient air is never drawn into the spring chambers and surrounding voids, extending the valve's reliability and life, at the same time maximising process availability for the valve user. In addition, as no impurities or moisture are drawn into the actuator, there can be no corrosion of the springs inside the actuator. The same feature also prevents the risk of biological growth, which could result in contamination of the process environment as a whole. The valve also protects against moisture ingress into the electronics of the control heads on the Element valves. Protection is required because small but naturally occurring changes in the control head pressure can lead to the penetration of moisture, particularly after a wash down cleaning process. Defence against this ingress is provided by diverting a small amount of clean control air into the control head, maintaining a slight positive pressure. In addition to their many operational benefits, the valves offer optimised interactiveness with the user. The valves integrate a modern operator concept that is intuitive and user-friendly, despite the extensive range of relevant functions provided. To prevent data overload, additional functions are displayed only as required, and the configuration of positioners and process controllers is seamless and automatic. Local communication is achieved at a glance via a high-performance and highly visible, multicoloured LED display that illuminates the surrounding area, passing on immediate user information regarding the valve status. Finally, all important data logging information is displayed on a backlit graphic display.