sight glass from LJ Star

Sight Glass available in six standard sizes that provide viewing areas ranging in size from approximately 3″ to 9″ in diameter. The weld-on assembly is designed to provide direct visual inspection of process vessels, separators, silos, pipelines and storage tanks. To illuminate the interior of the vessel, an optional LumiStar Light allows viewing and lighting through the sight glass port, saving the additional expense of a separate light port. Explosion proof lights, see USL05-Ex, and non-explosion proof lights, see USL13, are available as well. For a full selection, see Illumination Sources. To remove condensation and product build-up on the inside of the glass, try this unit in combination with Wiper Type I, Wiper Type II, or a spray nozzle.

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Assembly to the dimensions and constructional guidelines of DIN spec No. 28120 covering sizes DN 50 to DN 200.

Operating Conditions

Standard fittings are available for pressure up to 235 psi (depending on size, higher pressure rating on request). For temperature ratings (depending on material selection) see the following diagram.


Temperature ratings for high pressure weld-on sight glasses.

Parts and available materials:

Parts and available materials:

Item       Part Name              Material options

1              Weld Pad                316L SS (ASME Code Grade)

Steel (ASME Code Grade)

2.1, 2.2 Studs/Nuts              Steel – 5.6 or 304 SS – A2

3.1, 3.2 Gaskets                    PTFE (solid Teflon), Klinger C®-4400

  1. Sight Glass Disc   Tempered Borosilicate (280°C max)
  2. Cover Flange         Steel – RST 37.2 or 321 SS

Dimensions for circular sight glasses.