Forberg Scientific Inc: July 2012

Very good response sensitivity and optimized turn-down ratio Bürkert presents third generation of solenoid control valves

With the new Types 2871, 2873 and 2875 the fluid technology specialist Bürkert will present the third generation of its solenoid controlvalves in April 2012. Thanks to the new frictionless plunger bearing, the new solenoid control valves feature even better response and very good repeatability. In addition, the turn-down ratio (span) of the valves has been increased from 100:1 to 200:1 in comparison with the previous models.

Bürkert solenoid control valves are used around the world in numerous different applications in which fluids are mixed or metered. The applications range from medical, analytical and fuel cell technology to fuel metering and even systems for surface coating of oxyacetylene cutting systems. Since the presentation of the first generation of solenoid control valves in the early 1990s Bürkert has continuously improved the performance of its valves. The plunger bearing is of central importance in this development. The introduction of a new bearing principle now makes it possible to eliminate a guide bush, therefore providing a completely frictionless bearing for the plunger in the new Bürkert solenoid control valves.

Frictionless bearing increases precision

The elimination of solid-to-solid friction on the guide bush offers many benefits to users with high requirements. Valves with frictionless plunger bearings feature better response, meaning the position of the plunger already changes with minimal differences in the input signal. The repeatability in case of repeated setting of the same position is likewise improved by elimination of friction. Further, the span of the new solenoid control valves is increased to 200:1 instead of 100:1 as so far.

With the frictionless bearing Bürkert was also able to improve the behavior in use with low pressures (< 100 mbar). Stick-slip effects, which could be observed in the valves of the previous generations in some applications, have now been completely eliminated. No friction at the guiding elements of the solenoid control valves also means no temperature increases at the bearings during operation of the valve. The new generation of Bürkertsolenoid control valves can therefore also be used with very dry gases.

Second series for customized projects

In addition to the standard Types 2871, 2873 and 2875, Bürkert offers a second series of solenoid control valves with simplified technology as a more economical basic version. The Types 2861, 2863 and 2865 are aimed at customers who use large quantities of solenoid control valves in standard applications, with less stringent requirements for performance of the valves in favor of reducing costs. Depending on the requirement and the application, Bürkert therefore offers the optimal solenoid control valve for applications that require uncompromising performance as well as economical valve solutions for large-scale applications.

Facts and data

The new solenoid control valves of the standard series from Bürkert