Pressure, which builds up under certain constraints in front of a piston rod seal and which can reach several times the nominal pressure of the system.
The drag flow pressure is caused by the drag flow whose oil film is scraped off of the sealing lip and thus fills the sealing chamber (Figure S 29). The best remedy is a spiral-shaped nut in the guide bush, which can remove the scraped off oil volume without pressure.
Figure S 29: Creation of drag flow pressure