Bürkert’s Element control valve system is designed to deliver next-level accuracy of 0.1 percent over a service life of at least seven million cycles, which is more than three times the service life of conventional designs.
There are many criteria and design characteristics that enable an extended service life; Bürkert has combined these with outstanding precision, which is so important in processes that involve high-value ingredients.
Continuous, or modulating, control valves need to make adjustments several times per second while, at the same time, offering chemical resistance and an efficient actuator design.
Extending accuracy
More conventional valve designs use potentiometers with contacts and linkages to monitor the valve’s position, but over time, these can wear, introducing increased errors.
Bürkert’s innovative design uses induction sensors with no moving parts to ensure continued accuracy within 0.1 percent of the command position, even after 10 years in operation. In contrast, the accuracy of conventional valve designs can decline by 0.5 percent or more in just 18 months.
However, extended accuracy is only half the story – the operational service life and reliability of the valves are also essential to maintaining availability.
The investment in process equipment needs to be measured against the expected lifespan and any maintenance or replacement costs.
Boosting durability
Bürkert’s Element series incorporates an innovative internal air system that prevents the ingress of moist or contaminated air, extending the reliability of the whole valve, even in settings that require regular chemical washdowns.
Traditional designs use air pressure to open or close the valve against spring pressure.
However, when the valve is de-energised, the springs decompress and ambient air is drawn into the chamber.
The presence of air, moisture and chemicals has an adverse effect on the control components, causing corrosion that rapidly reduces reliability and increases maintenance costs.
Conversely, Element valves are sealed, instead recycling the clean, dry air used to pressurise the actuator back into the spring chamber. This key characteristic prevents the build-up of bacteria inside the actuator, which otherwise could potentially contaminate the hygienic atmosphere.
Clearly, all the materials used to create process valves are important for the durability of the equipment.
The polished stainless steel body ensures the external surfaces are free from corrosion while withstanding repeated, rigorous washdowns using chemical solutions.
The valve bodies are created with smooth surfaces to avoid any build-up of bacteria, helping to maintain a hygienic environment.
Beyond reliability
Pneumatically actuated valves require a constant supply of compressed air, which is a significant cost of operations. Since continuous control valves are in near-constant motion, air consumption can vary considerably between manufacturers.
The Element range is more compact than those from other OEMs and uses less compressed air.
In a process using 50 valves, for example, the decision to install Bürkert’s Element valves can result in an annual saving of £2,500. Furthermore, their lightweight design makes for easier handling and maintenance.
In all, there are many advantages to selecting the Element range, not least the excellent support offered by Bürkert to ensure the most effective and efficient process design is installed and commissioned.
For more information about these and other benefits, get in touch with Bürkert’s team at sales.uk@burkert.com to discuss your application today.