TSV three-way ball valve Three-way ball valves are widely used kinds of pipeline. They have three ports. They are commonly made such that flow coming in at one port can be directed to either the second port in one position or the third port in another position or in an intermediate position so all flow is stopped. According to the structural forms,the valves include one-piece type,two-piece type and three-piece type flanged ball valves,wafer flanged ball valves,and some butt-welding and socket welding ball valves