Abstract: A ball valve having an anti-rotational pressure plate that allows for a balanced pressure load on a valve member is provided. Additionally, the pressure plate can also fix the rotation of an adjacent flow disk, allowing for angular-orientation specific flow characterizing features to be used with the flow disk. By fixing the rotation of the flow disk, the ball valve can characterize flows using a greater variety of flow disk geometries, including angular-orientation dependent and angular-orientation independent flow disks. Further, the pressure plate could also be directly in the form of a flow disk that has anti-rotation features.