Three-way valve

ISO 10628-2 (group 21, valves) / PIP PIC001

Drawn as

Three triangles meeting tip to tip: left, right and one pointing up from below, each with a pipe stub. Usually carries an actuator or handwheel.

Meaning

Diverting or mixing valve, e.g. a cooling-medium bypass (TCV) or a PSV changeover. With an actuator, arrows on the ports show the failed flow path. No dedicated component; use ball-valve or control-valve and note it.

Variants

A filled triangle marks the port that is normally closed
PSV changeover (interlocked) valves are often drawn as a pair of 3-way valves joined by a dashed mechanical link
Plug-type 3-way bodies show a small rectangle at the centre