A ball valve consists of a valve body with a rotatable ball to control flow. A ball valve as a throttling control device ideally uses a full port (full bore) or reduced port (reduced bore) mechanism. A port or bore is a cylindrical flow passage through the center of the ball, and when turned one-quarter of the way, the flow stops. The port of a full port or full bore ball valve equals the pipeline diameter and presents little or no restriction to flow to allow for pigging when not attenuated. The port of reduced port or reduced bore ball valve is smaller than the pipe to absorb a small amount of pressure drop.