Unique SmartValve Is Fast And Precise

This ultrafast switching valve is designed for high-speed pulsing of airflow, making it well suited for compressed-air blow-off, cooling, cleaning and drying applications where it reportedly brings higher efficiency and performance.

It can also handle other gases and liquids, offering similar benefits in dosing systems, agricultural sprayers, water injectors that reduce combustion-engine emissions, and many other applications that demand better control and sizable energy savings.

SmartValve technology was originally developed by the German Aerospace Center (DLR) for the European space mission Rosetta, as a cold gas control valve for the Philae lander – the craft which made the first-ever soft landing on a comet nucleus. Over the last few years KTW engineers have further refined the valve design for industrial applications, produced a range of sizes, and developed the power electronics that provides closed-loop control.

The SmartValve features a simple, robust and reliable design. The only moving internal part is a ball that opens and closes the valve. No other components like springs or membranes are necessary.

At rest, a pressure differential between the valve inlet and outlet keeps the ball on the valve seat. To actuate the valve, electric current energizes a solenoid coil in the valve housing. The resulting magnetic field force laterally pulls the ball off the seat — permitting flow. Shutting off power eliminates the magnetic field, flow forces return the ball back to the seat, and the valve closes. Extremely fast (1 msec), direct and stochastic switching allows for real-time applications. The fail-safe valve closes automatically in case of power loss.

SmartValves typically operate with pressure differentials of between 1 and 10 bar (14.5 to 145 psi), and system pressures can range up to 1,000 bar. Customized versions address special customer requirements. KTW has developed valves to work at pressure differentials of approximately 600 bar and at temperatures as low as -200° C (-328° F) and as high as 400° C (752° F).

Ball and valve seat diameters, and the magnetic system, determine operating characteristics like opening force and switching speed. Varying these parameters lets engineers easily adapt the valve to suit different requirements and applications. For example, applying higher current opens the valve faster, although actual switching speed depends on the fluid and pressure differential. Accuracy depends on the size of the valve and the fluid forces but, in general, pulse-to-pulse repeatability is extremely high, provided that the pressure differential is fairly constant.

The ball, seat and other parts in contact with media are made of stainless steel, and working surfaces are polished. However, certain plastics, such as PEEK, can be used for the valve seat if required. Thanks to the low-friction, low-wear design and minimal mechanical load, the valve has an extremely long service life of more than three billion switching cycles.