Offset between the center line of the shaft and seat ring
The shaft is mounted completely behind the facing of the disk and seat. The result is one continuous, uninterrupted facing. This provides a tight shut-off to be achieved as there are no more transitions between disk and shaft in the sealing area.
Offset between the center lines of the shaft and body
The shaft is positioned with a slight offset from the center line of the body. This gives the butterfly valve a flow-to-close (FTC) and a flow-to-open (FTO) closing direction. If the butterfly valve is installed in the standard FTC direction, the process medium helps keep the disk shut and press it into the conical seat.
Offset of the axis of the seat to the center line of the body
The beveled conical seat geometry allows for an almost frictionless rotary motion and reduces wear and tear when the valve is opened or closed. Breakaway torque caused by deformation can be ruled out. The conical facing ensures strict seat leakage requirements can be met.
The seat (labyrinth seal, 4) inside the body, which is protected against the medium flow directly into it, and the solid seat ring (3) can be replaced as the retaining ring (5) is removable.