Butterfly valve

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

Drawn as

Two short vertical lines across the pipe (wafer body between flanges) with a diagonal line through the middle (the disc) and a dot at its centre (the shaft).

Meaning

Quarter-turn disc valve used for large low-pressure lines: seawater, cooling water, firewater and HVAC. Can isolate or throttle.

Variants

Very common alternative (PIP-style): a bow-tie with a vertical line through the centre and a dot
Some legends draw the disc as a thin ellipse instead of a line
Triple-offset (metal-seated) types are only identified on the datasheet