Vortex flowmeter

Vortex flow meters infer flow from the frequency at which vortices shed from a bluff body placed in the stream. No moving parts, no wetted electronics, and they handle steam better than almost anything else at the price.

The two types in this range

• Standard vortex meters cover steam, compressed air and industrial gas from DN15 to DN300 at plus or minus 1.0 percent. A separate transmitter handles temperature and pressure compensation when you need mass or standard volume.
• Precession vortex meters are built for natural gas, with the temperature and pressure sensors integrated into the body. That makes them simpler to install on a gas train but less flexible outside that duty.

What decides the model

Start with the minimum flow, not the maximum. Vortex shedding weakens as velocity drops, and below the meter’s minimum Reynolds number the signal simply disappears. That is why a vortex meter that works perfectly at full rate can read zero overnight.

Then check the pipe layout. Vortex meters are the fussiest family on straight run, needing 15 to 30 diameters upstream depending on what sits before them. Our guide to vortex flow meter straight run requirements has the numbers by fitting type.

Then vibration. A vortex meter mounted on a line next to a reciprocating compressor will pick up mechanical vibration as signal noise. If the pipe shakes, choose something else.

Where they are the wrong answer

Low flows near the bottom of the range, viscous liquids, and lines with heavy vibration. For clean conductive liquids the electromagnetic family is more forgiving and more accurate.