AM-VFM Vortex Flow Meter

A vortex meter puts a body across the pipe and counts the vortices it sheds: the frequency rises with velocity, and velocity through a known bore gives volume. Because the counting element is the flow itself, there is nothing to wear — the datasheet specifies no moving parts and no mechanical wear — and the pressure loss is low. It reads liquid, general gas and steam on the same body, from DN15 full bore to DN2000 as an insertion.

The boundary is the bottom of the range. A vortex needs enough velocity to shed cleanly, so the datasheet asks for the working flow to sit between one-half and two-thirds of the upper limit; a large pipe at a trickle is a sizing error, not a meter fault. What you give up is the low end, tolerance of pulsation and vibration, and any use on media that coat the shedder — for those, the electromagnetic meter is the cheaper answer.