The reason for the VDHT valves being more dirt resistant than other high-pressure solenoid valves lies in the seat design. The other high-pressure solenoid valves in the market today have a poppet with a flat closing surface. The VDHT valves on the other hand have a cone shaped closing surface as shown on the picture.
Two things can happen when dirt comes in contact with the VDHT poppet:
- Some of the dirt will be flushed away from the poppet by the medium due to the shape of the poppet.
- The rest of the dirt will be pressed into the soft Teflon in the end of the poppet
The result is in both cases no internal leakage in the VDHT valves due to impurities in the medium. Comparing with other valves in the market using a flat closing in the poppet these valves often experience internal leakage due to dirt.
