Magnetic Level Gauge

A magnetic level gauge shows level the way a glass gauge does, but with no glass and no process fluid in the indicator. The float, sized for the liquid density, rides in a chamber connected to the vessel; a magnet inside the float flips a column of bi-colour flags or moves a shuttle in an indicator strip mounted outside the chamber. The chamber can be built for any pressure, temperature and material, and the indication stays visible from a distance without illumination.

Gauges are supplied to 5 m in a single chamber and longer in sections, for process conditions to 400 bar and −160 to +400 °C. Chamber and float materials are 316L stainless steel, Hastelloy, Monel and Inconel for high pressure and corrosion, or PVC, PP, PVDF, ETFE and PTFE for aggressive chemicals at moderate conditions. Mounting configurations are side-side, side-bottom, top-side and top-bottom with flanged, threaded or weld-stub connections, and vents, drains and isolation valves, insulation, steam tracing and a graduated scale are options. Interface versions use a float weighted to sit at the boundary between two liquids.

The same magnetic float can operate switches and transmitters strapped to the outside of the chamber, so one nozzle pair delivers local indication, alarms and a 4–20 mA HART or magnetostrictive signal without any additional penetration.

Magnetic level gauges are used on high-pressure, cryogenic and corrosive services in oil and gas, petrochemical, chemical, power, water treatment and marine.