Festo technology simplifies piezo valve integration and reduces energy consumption

Festo has developed piezo valve technology for gas handling that simplifies the replacement of traditional solenoid valves, facilitates integration and can reduce energy consumption by as much as 95%.

Extremely low energy consumption, coupled with silent, no-heat operation, makes piezo valve technology particularly attractive for laboratory and medical device applications. Low noise is prized for bedside medical instruments and devices and is also desired in the laboratories where a lot of instruments may be deployed. However, it has not been possible to simply replace standard magnetic solenoid valves with piezo technology because they operate very differently. For example, most of today's control solenoid valves are designed to operate at a voltage between 5 and 24V, whilst a piezo valve requires 310V and special control electronics.

To overcome this potential barrier to adoption, Festo has developed piezo technology that enables piezo valves to be easily integrated into systems architectures using a standard 12 to 24V supply. Historically, consistent manufacture of piezo valves has been difficult. Festo assures reliability by producing piezo cartridges that can be incorporated into the various components on fully automated, high output production machinery. The cartridges consist of the fragile ceramic bender mounted within a housing incorporating the injection-moulded port nozzles. The gas flows in or out through these nozzles.

Festo‘s VAVE-P piezo valve incorporates everything needed for easy actuation. The VAVE-P is operated as normal with 12 to 24V and generates the required piezo voltage internally. It includes simple, open-loop actuation electronics, 310V voltage generation and a 2-channel piezo driver stage with current limitation. The two-channel electronics in the VAVE-P makes it possible to actuate two valves for regulating the flow rate passing through the valve or a 3/3-way valve function for regulating the pressure, using separate piezo valves for pressurisation and exhausting. This 3/3 way option is a very easy way of controlling pressure and is unique to piezo technology. The interface for the VAVE-P is always the same: two analogue inputs and the flexible power supply of 12 to 24V. There is no easier way to replace a proportional solenoid valve.

Using Festo piezo technology, it is easy to set up a complete flow rate and pressure regulation system. Another example is the compact VEMD flow control valve combining a piezo valve, flow sensor and control electronics. This allows you to achieve a linear ratio between input voltage and output flow rate. Its counterpart for regulating pressure is the VEAB proportional pressure regulator. This is equipped with two piezo valves, again each with one piezo bender for pressurisation and one for exhausting, plus the necessary electronics and a pressure sensor. The VEAB therefore provides a complete closed-loop pressure control solution in the smallest installation space.

The ability to purchase piezo valves as standard off-the-shelf components which are simple to integrate is opening up applications and uptake within laboratory instruments and medical devices applications. For specialist applications, Festo provides an application engineering and design support service.