Transparent Level Gauge

The transparent level gauge is the direct-reading gauge for fluids that need to be seen, not just detected. Two toughened flat glasses are clamped on opposite faces of the gauge body, and the liquid column is viewed through both against the light. Colour, turbidity, foam and the interface between two liquids are all visible, which is why transparent gauges are chosen for boilers, process vessels with mixed phases and any service where the operator wants to see what is in the tank.

Gauges are built in sections up to 2.5 m and combined for longer ranges, for process conditions to 250 bar and −160 to +400 °C. Bodies are carbon steel, 316 or 316L stainless steel, or LF2 for low temperature, with borosilicate glass as standard and aluminosilicate for high temperature. On steam and alkaline services a mica shield protects the glass from etching; an illuminator makes colourless fluids and steam-water interfaces readable; and a graduated scale, insulation, electrical tracing and anti-frost protection suit hot and cryogenic installations. Mounting is side-side, side-bottom, top-side or top-bottom with flanged, threaded or weld-stub connections and isolating valves with ball checks.

A relay output is available where a switch is required.

Transparent gauges are used for level indication on steam boilers, cryogenic services and process vessels in oil and gas, petrochemical, chemical, power, water treatment, marine and general industry.