A friend of mine built the vacuum pump and wanted to use a bigger pump . He choose the VN-C4 model

This pump has a much higher current draw (4A) so that the power dissipated is around 43W...

I had to change the output Mosfet to a much bigger one : SUM45N25-58-E3

And this pump is a "piston" one and it was leaking even more thant the VN-C1 model !

Finally we found a way to prevent any leakage (from the pump side) while adding into the intake pipe a small plastic valve.

Insert this valve as close as possible to the pump intake and that's it ! No more leakage on the pump (still a few on the bag side into the following video !)

So that, if you properly seal the bag, the system will regulate the vacuum almost every hour or so. Cool !

Note that a 1 liter pressure tank was added to "smooth" the vacuum. Although not strictly needed, it is a good practice to add this.

This pump is quite powerful and empties the bag very quickly. However I do prefer the small model VN-C1 as it draws less current and is quieter even if it empties the bag at a slower speed. The video is with the VN-C4 pump.