Description

DIN 7080 Borosilicate Sight Glass Discs — High-Pressure Observation Windows

The Lumiglas DIN 7080 sight glass disc is the established industry standard for high-pressure observation windows in process equipment. Manufactured from thermally toughened Borosilicate Glass 3.3, it delivers exceptional optical clarity, chemical resistance, and long-term mechanical reliability. Every batch is manufactured and tested in conformance with DIN 7080-2005 and supplied with an EN 10204-3.1 material certificate as standard.

In addition to its standard pressure ratings, the DIN 7080 disc is engineered for extreme operating environments — withstanding thermal shock differentials up to 230 °C and pressures up to 200 bar in special high-pressure dimensions. As a result, it serves as a reliable direct replacement for MAXOS® brand sight glass discs across the full standard size range.

Material Performance & Technical Specifications

Borosilicate Glass 3.3 combines low thermal expansion with high chemical durability — making it the material of choice for demanding process observation. Specifically, its hydrolytic resistance class HGB 1 (per DIN ISO 719) ensures negligible glass dissolution even in prolonged contact with water and steam at elevated temperatures. Furthermore, its acid resistance rating of A2 (DIN ISO 695) means it withstands most mineral acids without surface degradation.

Why Choose DIN 7080 Borosilicate Sight Glass?

Unlike standard soda-lime glass, Borosilicate Glass 3.3 maintains its mechanical and optical properties across a wide temperature range. Moreover, the DIN 7080 standard mandates tighter dimensional tolerances and surface quality requirements than generic flat glass — ensuring consistent seating in standard sight glass housings and reducing the risk of gasket blow-out under pressure cycling.

For this reason, DIN 7080 discs are specified by process engineers as the preferred replacement for OEM sight glass discs in vessels, reactors, autoclaves, and sight glass fittings across the chemical, petrochemical, food processing, and pharmaceutical industries.

Standard Dimensions — DIN 7080

The following dimensions conform directly to the DIN 7080-2005 standard size series. All discs are available with Lumiglas part codes and serve as direct replacements for corresponding MAXOS® codes.

All dimensions per DIN 7080-2005. For sizes not listed, custom dimensions are available on request.

Special & High-Pressure Dimensions

Beyond the standard DIN 7080 size series, Lumiglas supplies a range of special dimensions optimised for compact high-pressure applications and specific equipment requirements. Notably, several of these dimensions are rated to 150 bar and 200 bar — making them suitable for autoclave viewports, hydraulic test benches, and high-pressure reactor observation. These discs likewise serve as direct MAXOS® code replacements.

Pressures shown in red indicate high-pressure special dimensions (≥95 bar). Contact Lumiglas for the complete special dimension list.

Typical Applications

DIN 7080 borosilicate sight glass discs are specified across a wide range of industrial process equipment. In particular, they are used wherever a standardised, certifiable observation window is required under pressure and temperature cycling conditions.

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  Pressure vessels & reactors — chemical, petrochemical and pharmaceutical process equipment requiring DIN-certified observation windows
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  Autoclaves & sterilisers — high-pressure steam environments up to 200 bar (special dimensions)
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  Sight glass fittings & flow indicators — direct replacement discs for DIN sight glass housings and inline flow indicators
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  Storage tanks & mixers — food, dairy and beverage vessels requiring hygienic visual inspection with certified glass
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  MAXOS® replacement — direct cross-reference to MAXOS® sight glass disc codes; no housing modification required