Ball Valve is a rotating valve in 90 deg for opening/closing. It is a compact valve and light weight. It is widely used for open/close application, not for controlling the flow. It is low friction valve because there is not any obstruction when the valves open.
There are several type of ball valves such as 1-piece ball valve, 2-piece ball valve, 3-piece ball valve and etc. The materials are available in Cast Iron, Stainless Steel.