In addition, the worm and worm groove depth of the pressure increased, in the end, reduce exhaust gate-rotor from the single slot, depth is zero, it does not exist.

Raised-face seat. A groove around the seat collects particles pushed aside by the knife and prevents clogging. When the valve opens, media pressure cleans the groove.

The results of calculation indicates that the static axial stiffness of fluid film in double spiral groove face seal is improved due to the pressure loss through feeding holes.