KAYDEN 800 Series thermal dispersion flow/level/interface switches serve flare stack and pipeline applications. They commonly monitor flow plus provide leak detection/warning devices monitoring PSV or rupture disk.
In flares they give sensitivity and digital repeatability to perform required system test with a reduced volume of gas for less gas consumed and reduced emissions. In leak detection devices they note very small flow rate changes (or very low flows) as would be found if a PSV lifts or a pinhole develops in a rupture disk.
Kayden Instruments, Calgary, AB, Canada