Ball valves are classified as a quarter turn shut-off valve which controls the flow of fluid or gas with its rotating ball. These valves are known as a full port valve as the spherical ball has a straight bore right through it meaning that the flow path has no restriction of flow. This is because it is equal to the inside diameter of the pipe or tube that it is mounted to.
The valve can be opened or closed by turning the lever on the top of the valve. For the flow to pass, the bore should be aligned with the flow of the fluid. To block the flow, the ball can be rotated perpendicular to the flow path.
These valves are very versatile as they can be used in a wide range of applications as they can withstand high temperatures and pressures, easy to use and inexpensive.