Transparent level gauge

This design provides a level indication off (colorless) liquids and gases. In a transparent level gauge, a sight glass is mounted on either side of the medium. This way you can see through the media. Due to difference in transparency of the liquid, gas or vapor, the level can be read. At higher temperatures or heavy glass corrosion attach of the medium, mica is fitted. This reduces the visibility slightly, in order to improve the visibility on the rear side there may be a special lamp mounted in order to better read the level. Due to the special lighting, the light refraction/reflection in the liquid, gas or vapor separation surface is better utilized.

The cured transparent borosilicate glass (to DIN 7081) is mounted in a robust stainless steel or mild steel column with flanges.


  • Material: 1.4571, RSt 37-2.
  • Pressure: PN 40, PN 64, PN 100, PN160, PN 250.
  • Glass: DIN 7080 standard borosilicate, aluminosilicate or quartz glass.
  • Connection: UNI, ANSI or DIN flanges.
  • Connection Position: top/bottom, back, left or right next to the sight glass body.
  • Valve or tap.
  • Exhaust air / tap.
  • Safety ball: no liquid / gas loss by glass breakage.
  • Non frost extension: in situations with extreme freezing conditions a plexiglass block can be mounted perpendicular to the glass in order to check the level.
  • Mica can be mounted on the fluid side in order to prevent glass corrosion. This is recommended for > 22 bar steam.
  • Mica can be mounted on the outside of the glass to reduce thermal shock of the sight glass.
  • Lighting.
  • Depending on implementation this product corresponds to the PED 97/23 / EEC Art. 3 par. 3 SEP (Sound Engineering Practice). Applied rules as per TRD / AD200 or ASME-Boilers.
  • 2.1 or 3.1 certificate.
  • Other versions on request.