DIN 28120 Round Vessel Sight Glass Fittings
Lumiglas DIN 28120 weld-on vessel sight glass. DN50–DN200, rated
10–16 bar, borosilicate or soda-lime glass. SS flanges, EN 10204-3.1
cert. Custom pressure up to 70 MPa. Request quote →
Description
DIN 28120 Round Vessel Sight Glass Fittings
The DIN 28120 vessel sight glass is a robust, circular, weld-on sight port designed for the visual inspection of process vessels, tanks, and high-pressure equipment. Available in standard sizes from DN50 to DN200, these fittings are engineered to meet strict industrial safety standards.
Our units support high-performance borosilicate glass (DIN 7080) or soda-lime glass (DIN 8902) and are compatible with stainless steel or carbon steel flanges. They are the industry standard for monitoring filling levels, reaction processes, and color clarity in the chemical, pharmaceutical, and petrochemical sectors.
Key Benefits of DIN 28120 Sight Glasses
- Standards-Compliant Design: Manufactured strictly to DIN 28120 dimensional guidelines, ensuring seamless integration into existing pressure vessel designs.
- High Pressure & Temp Capability: Standard ratings of PN10 / PN16. With Borosilicate glass, these fittings withstand temperatures up to 280°C (and higher with specialized materials).
- Zero Distortion: The precision-machined base flange prevents glass stress during welding, ensuring optical clarity and safety.
- Versatile Customization: Available with wiper systems, explosion-proof lighting (Ex-rated), and varying gasket materials (PTFE, Silicone, Klingersil).
Typical Applications
These weld-on sight glasses are essential components for:
- Chemical Reactors
- Pharmaceutical Fermenters
- Food & Beverage Tanks
- Oil & Gas Separators
Technical Specifications
- Pressure Resistance: Standard 10 bar to 16 bar. (Custom high-pressure solutions up to 70 MPa available).
- Temperature Range: Up to 280°C with DIN 7080 Borosilicate Glass; higher with Quartz/Sapphire options.
- Certifications: EN 10204 3.1 Material Certificates available. Pressure equipment directive compliant.
Figure 1: Exploded view of the circular sight glass fitting showing the welding flange, gaskets, glass disc, and cover flange assembly.
1. Component Materials (Standard Configuration)
| Pos. | Part Name | Standard Materials |
|---|---|---|
| 1 | Base Flange (Welding pad) | Stainless Steel 1.4571 (316Ti), Carbon Steel RSt 37-2, Hastelloy |
| 2 | Fastening Bolts | Stainless Steel A2/A4 or Carbon Steel 5.6/8.8 |
| 3 | Gaskets | KLINGERSil C-4400, PTFE, Silicone, EPDM, Graphite |
| 4 | Sight Glass Disc | Borosilicate (DIN 7080): Max 280°C | Soda-Lime (DIN 8902): Max 150°C |
| 5 | Cover Flange | Stainless Steel 1.4541, Carbon Steel RSt 37-2 |
2. Dimensional Data (DIN 28120)
| Size Parameter | Symbol | DN 50 | DN 80 | DN 100 | DN 125 | DN 150 | DN 200 |
|---|---|---|---|---|---|---|---|
| Rated Pressure (Bar) | PN | 10/16 | 10/16 | 10/16 | 10/16 | 10/16 | 10 |
| Viewing Diameter | d1 (mm) | 80 | 100 | 125 | 150 | 175 | 225 |
| Glass Diameter | d3 (mm) | 100 | 125 | 150 | 175 | 200 | 250 |
| Outer Diameter | D (mm) | 165 | 200 | 220 | 250 | 285 | 340 |
| Welding Neck Height | h2 (mm) | 30 | 30 | 30 | 30 | 36 | 36 |
FAQ: DIN 28120 Sight Glasses
What is the difference between DIN 28120 and DIN 11851?
DIN 28120 is a round, weld-on sight glass specifically for pressure vessels and industrial tanks. DIN 11851 is a sanitary union standard (screwed sight glass) used primarily in the food and pharmaceutical industries for pipe connections.
Can DIN 28120 be used with a wiper?
Yes, DIN 28120 fittings generally have a central bore that allows for the installation of mechanical wipers (type SW I or SW II) to clean the glass disc during operation.
Downloads & Documentation
Get the full technical drawings and pressure charts.
