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CF Borosilicate Vacuum Viewport
The CF Borosilicate Vacuum Viewport provides reliable optical access for high-vacuum and ultra-high-vacuum systems. Manufactured with a precision stainless steel ConFlat flange and high-quality borosilicate glass, it delivers excellent optical clarity, dependable vacuum sealing, and long-term performance in demanding scientific and industrial applications.
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Technical data
CF Borosilicate Vacuum Viewport Overview
The CF Borosilicate Vacuum Viewport is designed to provide a clear and durable optical viewing window for high-vacuum and ultra-high-vacuum systems. Featuring a precision-machined stainless steel ConFlat (CF) flange and high-quality borosilicate glass, it offers excellent transparency, reliable vacuum sealing, and outstanding mechanical stability.
The viewport is compatible with standard CF vacuum flanges and is suitable for applications requiring visual inspection, laser transmission, process observation, or optical diagnostics inside vacuum chambers. It is widely used in semiconductor manufacturing, thin-film deposition, vacuum coating, research laboratories, electron microscopy, and accelerator systems.
Available in multiple flange sizes and custom configurations, the viewport can also be supplied with quartz, sapphire, or other optical materials to meet specific wavelength, temperature, or pressure requirements.
CF Borosilicate Vacuum Viewport — Technical Data
| Project Description | Parameters |
|---|---|
| Model | CF16-250 |
| Structure | 304/316 Stainless steel flange+4J29 Kovar alloy+Alkali borosilicate glass + low-temperature glass powder (or silver-copper-indium-tin active brazing filler metal) |
| Temperature resistance | -40 ℃/+200 ℃ |
| Ultimate vacuum/leakage rate | 1.0*10⁻¹¹ Torr/1.0*10⁻¹¹Pa.m³S⁻¹ |
| Baking (heating/cooling) rate | ≤3 ℃/min |
| Flange surface treatment | Electropolishing |
| Kovar alloy | 4J29 |
| Brazing materials | low-temperature glass powder (or silver-copper-indium-tin active brazing filler metal) |
| Glass materials | Alkali borosilicate glass |
| Glass transmission wavelength (nm) | 360-2500 |
| Transmittance T=% | 365nm T≥67% 380-1100nm T≥85% |
| Glass-face PV | PV 1/2–1/20 |
| Glass surface smoothness | 80/50、60/40、20/10 |
| Non-magnetic treatment of metal parts | Demagnetization processing according to customer requirements. |
CF Borosilicate Vacuum Viewport— Drawing
| Number | Specification | Glass size | glass material | Flange outer diameter | Number of bolt holes * diameter | center distance | Flange thickness |
|---|---|---|---|---|---|---|---|
| No. | Size | Glass | Material | D | N-Φd | Do | H |
| 1 | CF16 | 15.6*5 | Alkali borosilicate glass | 34 | 6*φ4.3 | 27 | 12 |
| 2 | CF20 | 23.6*5 | Alkali borosilicate glass | 54 | 6*φ6.6 | 41.3 | 15 |
| 3 | CF25 | 30.6*5 | Alkali borosilicate glass | 60 | 6*φ6.6 | 47 | 15 |
| 4 | CF40 (CF35) | 40.6*5 | Alkali borosilicate glass | 70 | 6*φ6.6 | 58.7 | 15 |
| 5 | CF50 | 51.6*5 | Alkali borosilicate glass | 86 | 8*φ8.4 | 72.4 | 20 |
| 6 | CF63 | 70.6*5 | Alkali borosilicate glass | 114 | 8*φ8.4 | 92.2 | 20 |
| 7 | CF80 | 85.5*6 | Alkali borosilicate glass | 130 | 16*φ8.4 | 110 | 20 |
| 8 | CF100 | 92.6*6 | Alkali borosilicate glass | 152 | 16*φ8.4 | 130.3 | 20 |
| 9 | CF160 | 144.6*8 | Alkali borosilicate glass | 202 | 20*φ8.4 | 181 | 22 |
| 10 | CF200 | 190.6*10 | Alkali borosilicate glass | 253 | 24*φ8.4 | 231.8 | 24.5 |
| 11 | CF250 | 246*12 | Alkali borosilicate glass | 305 | 32*φ8.4 | 284 | 26 |
KEY FEATURES
High Vacuum Compatibility
Designed for high-vacuum and ultra-high-vacuum applications.
Reliable Vacuum Seal
Precision CF flange ensures dependable leak-tight performance.
Durable Stainless Steel Body
Corrosion-resistant construction for long service life.
Wide Size Availability
Compatible with standard CF flange dimensions.
Thermal Stability
Accurate dimensions and polished sealing surfaces
Custom Materials Available
Optional quartz, sapphire, ZnSe, CaF₂, or fused silica windows.
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 CF vacuum viewport is a ConFlat flange-mounted optical window that allows visual inspection, laser transmission, or optical access while maintaining a high-vacuum or ultra-high-vacuum seal.
A:Borosilicate glass provides excellent optical clarity, thermal stability, and cost-effective performance for many high-vacuum applications.
A: Our CF vacuum viewports are suitable for high-vacuum (HV) and ultra-high-vacuum (UHV) systems with helium leak rates as low as 1×10⁻¹⁰ mbar·L/s.
A:Standard sizes include CF16, CF35, CF63, CF100, CF160, CF200, and CF250. Custom sizes are also available upon request.
A: Yes. We also manufacture CF viewports with fused quartz, fused silica, sapphire, ZnSe, CaF₂, BaF₂, MgF₂, and other optical materials for specialized applications.
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