Fresh steam control for food and beverages

By Greg Sutcliffe

Bürkert's new Element range of intelligent process control valves give a fresh look to steam control.

With companies who compete in global markets wishing to make production processes as economical as possible, there is an increased demand for automation solutions at the plant level. Intelligent process valves with integrated automation functions offer a more viable and efficient alternative to the conventional approach of centralised automation.

With a de-centralised system, only status monitoring and optional control are handled by the central process control system. This means that at the plant level, pneumatically operated process valves can be equipped with on-board automation components such as pilot valves, electrical feedback units and optical status indicators, field bus interfaces and even highly accurate positioners and PID process controllers. This shift in process philosophy incorporated in Element allows food and beverage manufacturers to reconcile the commercial necessity for a high degree of production automation, with increased hygiene and food safety.

Hygiene and food safety naturally plays a key role in this market segment and safe production processes are at the forefront of the Element valve design. They feature the high IP protection demanded by food and beverage applications and are made exclusively from detergent-proof materials, which prevent them from the ill-effects associated with long-term use in demanding ambient conditions such as high air humidity, frequent wash-down cleaning with aggressive chemicals and high temperatures. When you compare Element valves to standard valve conventions, these features mark real progress for improved production hygiene. For instance they have internally integrated channelled air supply, allowing a smooth exterior design, making them to easy to clean and providing maximum production availability, thanks also in part to in-built functional safety.

One way this is achieved is via the unique air delivery system which delivers clean instrument air to both the actuator chambers, which ensures that the spring chamber is supplied only with pure, dry and clean instrument air. This prevents moisture, dust and contaminants in the ambient air from entering the actuator unit which, in turn, effectively prevents contamination of the piston seals and corrosion of the drive springs caused by cleaning solutions entering the housing. Not only does this significantly prolong the production availability of the actuator, it also enhances the hygiene of the whole process. In addition, as the actuator exhausts, it delivers clean instrument air into the control unit housing. As a result, a slight overpressure is ever-present in the control head, further improving its IP protection and eliminating condensation.

Our steam experience drives us to find new and practical solutions for the steam challenges we face daily. As a result of actively listening to our customers, we have introduced some surprising features to set us apart. Each globe valve body is offered with at least three valve trim options. These parabolic trims provide the user the choice and flexibility to change the trim at a later date if the process conditions change, but also allow you to fit 'line-sized' control valves with reduced trims to your steam pipework, reducing the time and work needed on site during installation. In addition, our continuous control valve bodies are offered exclusively from cast 316L stainless steel as standard. Lighter in weight, robust and beautiful, stainless steel sits perfectly in the food and beverage environment, maintaining a great long lasting exterior look, without peeling paint to make a nuisance of itself.

We also know that in food and beverage steam applications, there are three things you will surely find - humidity, heat and product. Our Element valves are constructed from clean stainless steel and temperature resistance PPS, making them durable and tough enough to live in this demanding world. The internal routing of both the air channels and stroke position feedback means that we avoid the cumbersome external linkages, connections and sliders found in more conventional general purpose control valves, thus removing as much as possible places where product can sit and attract unwanted attention!

Biography

Greg Sutcliffe is the Steam Segment Manager for Bürkert Fluid Control Systems. Bürkert is at the forefront of continuous customer-oriented innovation, a true single source for hardworking valve elements, process controllers and sensors. Greg is a regular steam blogger and article contributor, as well as a passionate steam trainer with an enthusiasm for engaging with steam users around the world.