Ball valves use a spherical disc to control the flow between pipes, tubes, or hoses. Flow is allowed when the hole that pierces the ball-shaped disc is in line with the inlet and outlet of the valve and is blocked when the ball is horizontally swiveled 90 degrees, so that the hole of the ball is perpendicular to the opening of the valve. Ball valves can be referred to as full port or reduced port (also known as regular or standard port) depending on the inner diameter or the valve. A ball valve is full port if the hole of the ball is the same size as the inner diameter of the connecting pipeline (resulting in lower friction) and termed reduced port if the hole of the valve is one pipe size smaller than the pipe, resulting in less flow through the valve than through the shaft of the pipe. Ball valves may have a handle or lever that aligns with the ball’s position (open or closed) for manual operation. They are primarily used in air, gas, liquid, and steam applications.