Among the solenoid valves (coil) or the electromechanically operated valve, the direct acting proportional solenoid valves differ in terms of operation and field of application. Let’s discover together how and why they differ. The direct-acting proportional solenoid valve of the VPD series, for example, is conceived by making some constructive changes to the classic shut-off solenoid valve, which works only in the ON / OFF state.
Operation of the direct acting proportional solenoid valves series VPD
As anticipated above, the operating principle of this series of valves is characterized by the actuation system. In normal on-off valves, by applying an electric current to the coil of a shut-off valve it is generated a magnetic field proportional to the current, which moves the stem and the shutter, overcoming the force of the antagonist spring which normally holds the valve closed up, until the passage is completely open. In the case of the VPD series proportional solenoid valve, instead, the particular profile of the movable stem with the electromagnet and the regulation of the current in the coil make it possible to continuously vary the balance between the strength of the magnetic field, which moves the stem and the shutter, and the antagonist spring, in order to position the shutter in intermediate positions, between maximum opening and closing, to control and adjust the flow rate of the fluid. The characteristic curve “electric current (A) / flow rate (F)” of this type of proportional solenoid valves is thus created.
Advantages of proportional solenoid valves
- Low hysteresis
- High repeatability
The proportional valves 2/2 N.C. are available with brass body and G1/8″ connections, with 22mm interface and CNOMO interface. They can have different nominal diameter (ø) and different nominal flow rate (Qn – Kv). It is also possible to manufacture proportional valves with customized functional characteristics.
Example of use
- Pressure control
- Power proportional valve control
- Flow rate control
- Temperature control
- Ejector control for vacuum plants
- Mixing of hot and cold water