Venturi tube

ISA 5.1-2009/2022 (primary element symbols) / PIP PIC001

Drawn as

The line narrows through a short throat and widens again (converging and diverging lines either side of the pipe), with an FE bubble above.

Meaning

Low-loss dp flow element for large water and gas lines and multiphase meters (venturi + gamma). No dedicated component; orifice-flowmeter is the nearest dp meter.

Variants

Some legends draw it as a box with "V"
Multiphase flow meters (MPFM) combine a venturi with a gamma densitometer box