压电技术的原理与电磁阀完全不同。其核心元件是压电陶瓷。当压电陶瓷带电时，就会发生极化并弯曲。这种弯曲与施加的电压成正比，因此可以实现成比例的流量或压力控制。所以电压越高，流量就越大。其电流消耗曲线看上去与比例电磁阀完全不同，比例电磁阀的线圈必须始终通电， 只有这样才能产生磁场，从而将衔铁从阀座上抬起。相比之下，压电阀无需恒定的电流。它像电容器那样工作。最初的电流足以为陶瓷一次性充满电，之后电流消耗几乎为零。
A 2/2-way valve is a very easy way of controlling a flow rate. It has one bender and two ports. The more voltage is applied, the further it opens.
A 3/3-way valve has three ports and two benders. A complete pressure regulation system can be set up with this compact solution. There is one bender for pressurisation (or increasing the pressure) and a second one for exhausting (or reducing the pressure). The third state is closed; this is when the pressure is maintained. A 3/3-way valve like this is a very easy way of controlling the pressure. Solenoid valves do not have such a 3/3-way function.
As mentioned earlier, piezo valves do not operate using 12 V – they need special electronics. To make actuation much easier, Festo has developed piezo driver electronics in the shape of the new solution VAVE-P that has everything needed for piezo technology.
The VAVE-P is operated as normal with 12 to 24 V and generates the piezo voltage. It has everything you need for the specific actuation of piezo valves: simple open-loop actuation electronics, 310 V voltage generation and the 2-channel piezo driver stage with current limitation.
The two-channel electronics makes it possible to actuate two valves for regulating the flow rate or a 3/3-way valve for regulating the pressure with separate actuation for pressurisation and exhausting.
The interface is always the same, two analogue inputs and the flexible power supply of 12 to 24 volts. There is no easier way to replace a proportional solenoid valve.
There are also solutions that come with all the components required for a complete flow rate or pressure regulation system. The compact flow control valve VEMD from Festo combines a piezo valve, flow sensor and control electronics. This allows you to achieve an absolutely linear ratio of input voltage and output flow rate.
The counterpart for regulating pressure is the proportional pressure regulator VEAB with two piezo valves, in each case with one piezo bender for pressurisation and one for exhausting. Then there is also the electronics and a pressure sensor. This provides a complete closed-loop pressure control solution in the smallest installation space.