L-port or T-port?
An L-port 3-way ball valve connects the bottom port to one side port at a time, so it is used for diverting one supply between two outlets or selecting between two inlets. A T-port valve can also connect all three ports or pass flow straight through, which suits mixing and bypass duties, but a standard T-port valve cannot isolate all three ports. Our guide to L-port vs T-port 3-way ball valves explains the flow positions and 90° vs 180° actuation in more detail.
In stainless steel, choose from 3-way BSPP full bore ball valves (BV-L5300/5400, 1/2" to 4", 1000 PSI), 3-way BSPP reduced bore ball valves (BV-L5000/5100) and 3-way flanged PN16/PN40 ball valves (BV-L5K00/5N00). For building services there are 3-way brass ball valves, and for chemical dosing and water treatment PVC metric and PVC imperial 3-way ball valves.
The stainless steel 3-way valves can be supplied as pneumatic or electric actuated ball valves with the port configuration and fail position you specify.