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Flat Rectangular Sight Window
The Flat Rectangular Sight Window is designed for clear visual inspection of industrial vessels, tanks, reactors, and processing equipment. Its flat viewing surface provides distortion-free observation while maintaining reliable sealing performance under pressure and temperature conditions.
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Technical data
Flat Rectangular Sight Window for Industrial Process Observation
The Flat Rectangular Sight Window is a high-performance inspection window designed to provide safe and clear observation inside industrial tanks, pressure vessels, reactors, separators, and processing systems.
Featuring a flat transparent viewing panel mounted within a robust metal frame, the sight window allows operators to monitor liquid levels, product conditions, mixing processes, crystallization, sediment formation, and equipment operation without opening the vessel.
Compared with curved or circular viewing windows, the flat rectangular design offers a larger viewing area and distortion-free visibility, enabling more accurate process monitoring.
Manufactured from premium borosilicate glass, tempered safety glass, fused quartz, or customized transparent materials, the window delivers excellent optical clarity, thermal resistance, and mechanical strength.
The frame assembly is available in stainless steel 304, stainless steel 316L, carbon steel, duplex stainless steel, and other corrosion-resistant alloys to meet the requirements of demanding industrial environments.
Flat Rectangular Sight Windows are widely used in chemical processing, pharmaceutical manufacturing, food and beverage production, biotechnology, petrochemical plants, power generation facilities, and water treatment systems.
Flat Rectangular Sight Window— Technical Data
| Item | Details |
|---|---|
| Application | Rectangular Lumistar sightglasses of the series RSG / RSGR / RSGRR may be used to observe the interior of reactors, columns, silos, vessels, storage tanks and pipelines. They serve mainly as liquid level gauges. They are delivered ready to be welded into or onto a vessel wall, complete with the appropriate seals, glass plates, and cover fastenings. |
| Operating conditions | Nominal pressure 16 bar, Vacuum Note: The nominal pressure indicated refers to the design base of the sightglass. When welded into the vessel concerned, the base frame becomes part of the vessel wall. It is necessary, therefore, that appropriate strength calculations are made on all vessels concerned with respect to the design pressure and size of the vessel and in accordance with the relevant design code. If found to be necessary, reinforcement of the vessel wall has to be carried out. |
| Operating temperatures | 100°C max. with sodium silicate glass to DIN 8903 243°C max. with borosilicate glass to DIN 7081 Note: The above indicated temperatures refer to the use of unprotected glassplates, with no protective mica sheets. |
| Standard materials | Base frame: RSt 37-2 or HII (boiler plate) /AISI 316 Ti stainless steel Cover frame: As base frame Glass plate: Toughened sodium silicate glass to DIN 8903 (max.100 °C); Toughened borosilicate glass to DIN 7081 (max.243°C) Gaskets: KLINGERsil C4400 / Neoprene PTFE / Viton Cover fastenings: Steel, quality 8.8 / Stainless steel Other materials on request. |
| Certificates | To be supplied against extra charge to DIN EN 10204. |
| Options | – Version with closed base frame (drawing left) to be used as an external liquid level gauge with top and bottom pipe connections. For this application, the base frame will be supplied appropriately drilled and tapped. – Radiused base frame to suit vessel wall – Clear (transparent) glass plate – Alternative versions in shape and size |
| Remarks | The approval does not apply to the base flange as this is considered as part of the vessel wall after welding. Standard delivery includes a reflex(fluted) glass plate. In circumstances where a clear (transparent) glass plate is required, this must be clearly stated at the time of enquiry. After welding into the vessel, the base frame should be checked to ensure that the sealing surface is flat and has not become distorted to avoid possible leakage under pressure and / or breakage of the glass plate during tightening of the cover frame bolts. This process should be carried out in several steps and progressively alternating between each pair of opposite bolts from one end of the frame to the other! Tighten first little, then repeat the operation. |
Flat Rectangular Sight Window— Drawing
| Type RSG / RSGR / RSGRR | Size | Length A | Number of units | Free view C | Glass-length B | Bolts number D | Weight (kg) |
|---|---|---|---|---|---|---|---|
| RSG / RSGR / RSGRR | 170 | 170 | 1 | 124 | 140 | 8 | 2,70 |
| RSG / RSGR / RSGRR | 250 | 250 | 1 | 204 | 220 | 10 | 4,40 |
| RSG / RSGR / RSGRR | 300 | 300 | 1 | 264 | 280 | 14 | 5,00 |
| RSG / RSGR / RSGRR | 350 | 350 | 1 | 304 | 320 | 16 | 6,00 |
| RSG / RSGR / RSGRR | 400 | 400 | 1 | 354 | 370 | 18 | 7,00 |
| RSG / RSGR / RSGRR | 500 | 500 | 2 | 2 × 204 | 2 × 220 | 20 | 9,10 |
| RSG / RSGR / RSGRR | 600 | 600 | 2 | 2 × 264 | 2 × 280 | 28 | 10,50 |
| RSG / RSGR / RSGRR | 700 | 700 | 2 | 2 × 304 | 2 × 320 | 32 | 12,00 |
| RSG / RSGR / RSGRR | 800 | 800 | 2 | 2 × 354 | 2 × 370 | 36 | 14,00 |
| RSG / RSGR / RSGRR | 1000 | 1000 | 4 | 4 × 204 | 4 × 220 | 40 | 17,00 |
KEY FEATURES
Thermal Stability
High resistance to thermal shock for extreme temperature environments
High Mechanical Strength
Suitable for pressure-loaded industrial systems
Chemical Resistance
Stable performance in corrosive chemical environments
Excellent Transparency
Clear visibility for process monitoring
Precision Manufacturing
Accurate dimensions and polished sealing surfaces
Custom Design Support
OEM / ODM customization available
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 Flat Rectangular Sight Window is an industrial inspection window used for visual observation inside tanks, vessels, reactors, and process equipment.
A:The flat design provides distortion-free visibility and a larger observation area, allowing operators to monitor processes more accurately.
A: Yes. Dimensions, frame materials, glass materials, gasket types, and pressure ratings can all be customized.
A: Yes. All sight glass discs are supplied with precision ground or polished edges for reliable installation.
A: Yes. The assembly can be engineered to meet pressure vessel requirements according to operating conditions.
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