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DIN 28120 Double Window Sight Glass for Pressure Vessels
DIN 28120 Double Glazed Sight Glass (DVG 28120) is designed for safe visual inspection of pressure vessels, tanks, reactors and process equipment. The double glass structure helps prevent fogging and reduces heat transfer, ensuring clear observation under demanding industrial conditions.
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Technical data
DIN 28120 Double Glazed Vessel Sight Glass (DVG 28120)
The DIN 28120 double glazed sight glass is a high-performance observation window designed for pressure vessels, reactors, storage tanks and industrial process equipment.
Compared with standard single glass sight glasses, the double glazed design provides an additional insulation layer between two glass discs, helping reduce condensation, prevent fogging and improve viewing clarity during high temperature or low temperature applications.
The sight glass assembly consists of a welded flange, cover flange, double borosilicate glass discs and sealing gaskets. It can be customized with different flange materials, gasket materials and optional lighting accessories.
The design is suitable for industries including chemical processing, pharmaceutical, food & beverage, biotechnology and energy equipment.
DIN 28120 Double Glazed Vessel Sight Glass
Technical Data
| Parameter | Specification |
|---|---|
| Product Type | Double Glazed Vessel Sight Glass |
| Model | DVG 28120 |
| Standard | DIN 28120 |
| Installation Type | Weld-On Type |
| Application | Pressure Vessel / Tank / Reactor |
| Nominal Size | DN50 – DN200 |
| Glass Material | Borosilicate Glass DIN 7080 |
| Glass Structure | Double Glass Design |
| Flange Material | SS304 / SS316L / Carbon Steel |
| Cover Material | Stainless Steel |
| Gasket Material | PTFE / Graphite / EPDM / Silicone / Customized |
| Operating Temperature | Up to 280℃ (depending on glass & gasket) |
| Pressure Rating | Up to PN16 (depending on size and design) |
| Surface Treatment | Polishing / Electropolishing Available |
| Connection Method | Welding |
| Inspection Type | Direct Visual Observation |
| Certificate | EN10204 3.1 Available |
DIN 28120 Double Glazed Vessel Sight Glass— Component Materials
| Component | Material Specification |
|---|---|
| Base flange | Boilerplate, stainless steels, Titanium, Hastelloy etc. |
| Gaskets | KLINGERsil C 4400, Silicone, PTFE etc. |
| Sightglass discs | Sodium silicate to DIN 8902 |
| Borosilicate to DIN 7080 | |
| Intermediate ring | Boilerplate, stainless steels, Titanium, Hastelloy etc. |
| Cover flange | Boilerplate, stainless steels, Titanium, Hastelloy etc. |
| Tightening bolts | 8.8, A2, A4 |
DIN 28120 Double Glazed Vessel Sight Glass— Drawing and Dimensions
| Nominal Diameter (DN) | Pressure rating (PN) | Viewing Diameter d1 | Glass discs | Base flange and cover flange | Bolts or studs / nuts | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| d4 | s | D | k | h1 | h2 | L | Number | Size | Tightening torque (Nm) | ||||
| 50 | 6 | 80 | 100 | 10 | 165 | 125 | 30 | 65 | 4 | M16 | |||
| 10 | 15 | 16 | 75 | 28 | |||||||||
| 16 | 15 | 75 | 32 | ||||||||||
| 80 | 6 | 100 | 125 | 15 | 200 | 160 | 18 | 30 | 75 | 8 | M16 | ||
| 10 | 15 | 20 | 75 | 20 | |||||||||
| 16 | 20 | 20 | 95 | 23 | |||||||||
| 100 | 6 | 125 | 150 | 15 | 220 | 180 | 18 | 30 | 75 | 8 | M16 | ||
| 10 | 20 | 22 | 90 | 26 | |||||||||
| 16 | 25 | 22 | 100 | 30 | |||||||||
| 125 | 6 | 150 | 175 | 20 | 250 | 210 | 18 | 30 | 85 | 8 | M16 | ||
| 10 | 20 | 25 | 90 | 32 | |||||||||
| 16 | 25 | 25 | 100 | 34 | |||||||||
| 150 | 6 | 175 | 200 | 20 | 285 | 240 | 18 | 36 | 85 | 8 | M20 | ||
| 10 | 25 | 30 | 110 | 47 | |||||||||
| 16 | 30 | 30 | 120 | 54 | |||||||||
| 200 | 6 | 225 | 250 | 25 | 340 | 295 | 20 | 36 | 100 | 8 | M20 | ||
| 10 | 30 | 35 | 125 | 63 | |||||||||
KEY FEATURES
Double Glazed Design
Dual glass structure helps prevent condensation and ensures clear visibility during operation
Thermal Stability
High resistance to thermal shock for extreme temperature environments.
DIN 28120 Standard
Designed according to DIN 28120 requirements for reliable vessel installation
Corrosion Resistance
Stainless steel construction ensures durability in harsh industrial conditions
High Transparency
Premium borosilicate glass provides excellent optical clarity for process monitoring
Customizable Configuration
Available with various gaskets, materials, lighting systems and accessories
Custom Manufacturing Service
We provide tailor-made solutions according to drawings or technical requirements.
- Custom diameter
- Custom thickness
- Special pressure design
- Edge polishing
- Optical finishing
- OEM / ODM support
- Custom packaging
TYPICAL APPLICATIONS
- Pressure Vessels
- Chemical Reactors
- Boilers & Steam Systems
- Pipeline Sight Glass Assemblies
- Pharmaceutical Equipment
- Food & Beverage Processing
- Industrial Observation Ports
FAQ
A: A DIN 28120 double glazed sight glass is a vessel observation window with two glass discs designed for monitoring internal processes while reducing condensation and heat transfer.
A:The double glass structure provides better insulation performance and helps prevent fogging, making it suitable for temperature difference applications.
A: The standard glass is borosilicate glass according to DIN 7080, which provides excellent thermal shock resistance and high temperature performance.
A: Yes. EN10204 3.1 certificates are available for flange materials and customized orders.
A: Yes. The cover flange can be customized with mounting holes for sight glass illumination systems.
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