CF Sapphire Observation Window Custom Size
High-performance UHV vacuum viewport windows with metal-glass brazing seal. Borosilicate, fused silica & sapphire viewport optional, CF/KF/ISO flange, ultra-low leak rate for vacuum chamber optical observation & laser transmission.
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UHV Vacuum Viewport Windows
Our UHV vacuum viewport windows are designed and manufactured for demanding high and ultra-high-vacuum applications where direct visual observation and non-intrusive optical access to sealed vacuum chambers is required. Our products are not like common vacuum sight glasses, they combine mature glass-to-metal sealing craftsmanship and high-purity raw materials to solve the common problems of traditional viewports, such as air leakage, low transmittance, poor temperature resistance and fragile structure.
Helium leak detection and optical performance testing are performed on each viewport prior to delivery. It has the advantages of high pressure difference resistance and can withstand repeated high-temperature baking cycles and can maintain stable mechanical and optical properties in long-term continuous operation, making it the optimal supporting component for high-end vacuum systems.
Specification parameters
| High-temperature vacuum glass Viewports | A/mm | B/mm | D/mm | H/mm | n-φd/mm | Material | Temperature | Vacuum Degree | Positive Pressure |
| CF16 | 34 (1.33″) | 27 | 14 | 8 | 6-φ4.3 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF20 | 54 (2.12″) | 41.3 | 14 | 10.5 | 6-φ6 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF25m | 54 (2.12″) | 41.3 | 22 | 11.5 | 4-φ6.8 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF25 | 54 (2.12″) | 43 | 22 | 11 | 6-φ6 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF25b | 60 (2.36″) | 47 | 22 | 10.5 | 6-φ6.6 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF32 | 70 (2.75″) | 54 | 22 | 12 | 6-φ6.6 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF35 | 70 (2.75″) | 58.7 | 34 | 16.5 | 6-φ6 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF40 | 70 (2.75″) | 58.7 | 34 | 13 | 6-φ6.6 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF50 | 86 (3.38″) | 72.4 | 47 | 18 | 8-φ8 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF63 | 114 (4.50″) | 92.2 | 64 | 20 | 8-φ8.4 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF75 | 117.4 (4.62″) | 102.3 | 64 | 17.5 | 10-φ8.4 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF80 | 130 (5.12″) | 110 | 82 | 20 | 16-φ8.4 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF100 | 152 (6.00″) | 130.3 | 104 | 20 | 16-φ8.4 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF125 | 171.5 (6.75″) | 151.6 | 104 | 21 | 18-φ8.4 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF150 | 202 (8.00″) | 181 | 155 | 22 | 20-φ8.4 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF160 | 203.2 (8.00″) | 181 | 155 | 21 | 20-φ8.4 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF200 | 253 (10.00″) | 231.8 | 190 | 27 | 24-φ8.4 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF250 | 305 (12.00″) | 284 | 155 | 26 | 32-φ8.4 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF275 | 336.6 (13.25″) | 306.3 | 155 | 28 | 30-φ10.8 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF300 | 368.3 (14.50″) | 338.1 | 155 | 28 | 32-φ10.8 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF350 | 419.1 (16.50″) | 388.9 | 155 | 28 | 36-φ10.8 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF400 | 469.9 (18.50″) | 437.9 | 155 | 28 | 40-φ10.8 | 304 | 550℃ ↓ | 1*10E-9pa | 0.05mpa |
| High-pressure quartz vacuum Viewports | A/mm | B/mm | D/mm | H/mm | n-φd/mm | Material | Temperature | Vacuum Degree | Positive Pressure |
| CF10 | 25 (1.0″) | 17.5 | 10 | 6 | 6-φ3.3 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF16 | 34 (1.33″) | 27 | 16 | 7.3 | 6-φ4.3 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF20 | 54 (2.12″) | 41.3 | 20 | 10.5 | 6-φ6 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF25m | 54 (2.12″) | 41.3 | 25 | 11.5 | 4-φ6.8 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF25 | 54 (2.12″) | 43 | 25 | 10.5 | 6-φ6 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF25b | 60 (2.36″) | 47 | 25 | 10.5 | 6-φ6.6 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF32 | 70 (2.75″) | 54 | 32 | 12 | 6-φ6.6 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF35 | 70 (2.75″) | 58.7 | 35 | 13 | 6-φ6 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF40 | 70 (2.75″) | 58.7 | 40 | 13 | 6-φ6.6 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF50 | 86 (3.38″) | 72.4 | 50 | 16 | 8-φ8 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF63 | 114 (4.50″) | 92.2 | 63 | 17.5 | 8-φ8.4 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF75 | 117.4 (4.62″) | 102.3 | 75 | 17.5 | 10-φ8.4 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF80 | 130 (5.12″) | 110 | 80 | 18 | 16-φ8.4 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF100 | 152 (6.00″) | 130.3 | 100 | 20 | 16-φ8.4 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF125 | 171.5 (6.75″) | 151.6 | 125 | 21 | 18-φ8.4 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF150 | 202 (8.00″) | 181 | 150 | 22 | 20-φ8.4 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF160 | 203.2 (8.00″) | 181 | 160 | 21 | 20-φ8.4 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF200 | 253 (10.00″) | 231.8 | 200 | 24.5 | 24-φ8.4 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF250 | 305 (12.00″) | 284 | 250 | 26 | 32-φ8.4 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF275 | 336.6 (13.25″) | 306.3 | 275 | 28 | 30-φ10.8 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF300 | 368.3 (14.50″) | 338.1 | 300 | 28 | 32-φ10.8 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF350 | 419.1 (16.50″) | 388.9 | 350 | 28 | 36-φ10.8 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| CF400 | 469.9 (18.50″) | 437.9 | 400 | 28 | 40-φ10.8 | 304 | 250℃ ↓ | 1*10E-6pa | 0.2mpa |
| Ultra-high-temperature sapphire vacuum Viewports | A/mm | B/mm | D/mm | H/mm | n-φd/mm | Material | Temperature | Vacuum Degree | Positive Pressure |
| CF16 | 34 (1.33″) | 27 | 14 | 8 | 6-φ4.3 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF20 | 54 (2.12″) | 41.3 | 14 | 10.5 | 6-φ6 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF25m | 54 (2.12″) | 41.3 | 22 | 11.5 | 4-φ6.8 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF25 | 54 (2.12″) | 43 | 22 | 11 | 6-φ6 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF25b | 60 (2.36″) | 47 | 22 | 10.5 | 6-φ6.6 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF32 | 70 (2.75″) | 54 | 22 | 12 | 6-φ6.6 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF35 | 70 (2.75″) | 58.7 | 34 | 16.5 | 6-φ6 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF40 | 70 (2.75″) | 58.7 | 34 | 13 | 6-φ6.6 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF50 | 86 (3.38″) | 72.4 | 47 | 18 | 8-φ8 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF63 | 114 (4.50″) | 92.2 | 64 | 20 | 8-φ8.4 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF75 | 117.4 (4.62″) | 102.3 | 64 | 17.5 | 10-φ8.4 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF80 | 130 (5.12″) | 110 | 82 | 20 | 16-φ8.4 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF100 | 152 (6.00″) | 130.3 | 104 | 20 | 16-φ8.4 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF125 | 171.5 (6.75″) | 151.6 | 104 | 21 | 18-φ8.4 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF150 | 202 (8.00″) | 181 | 155 | 22 | 20-φ8.4 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF160 | 203.2 (8.00″) | 181 | 155 | 21 | 20-φ8.4 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF200 | 253 (10.00″) | 231.8 | 190 | 27 | 24-φ8.4 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF250 | 305 (12.00″) | 284 | 155 | 26 | 32-φ8.4 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF275 | 336.6 (13.25″) | 306.3 | 155 | 28 | 30-φ10.8 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF300 | 368.3 (14.50″) | 338.1 | 155 | 28 | 32-φ10.8 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF350 | 419.1 (16.50″) | 388.9 | 155 | 28 | 36-φ10.8 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
| CF400 | 469.9 (18.50″) | 437.9 | 155 | 28 | 40-φ10.8 | 304 | 610℃ ↓ | 1*10E-9pa | 0.05mpa |
Core Specifications & Material Advantages
1. Materials for Optical Windows
- Borosilicate Glass: Cheap option for general visible light observation; great chemical stability, great for general vacuum experiments and for industrial monitoring.
- Fused Silica (Quartz): Excellent UV transmittance, low thermal expansion coefficient, suitable for ultraviolet optical testing, high temperature vacuum situations.
- Single-Crystal Sapphire: Ultra high mechanical strength, temperature resistance (max 450°C bake-out); radiation resistant and magnetic field compatible, applicable to high energy and extreme working environments.
- Infrared Crystal Materials: Optional BaF2, CaF2, ZnSe and MgF2, specially customized for infrared spectroscopy, THz test and infrared laser transmission systems.
2. Flange Configuration
- Material: Premium 304/316 Stainless Steel, Anti-Corrosion and Rust Proof
- Type: ConFlat (CF) knife-edge flange, KF/NW quick flange, ISO big flange
- Customization: Available for magnetic sensitive experimental environment, non-magnetic flange; Different viewable diameter to choose, from 0.5” to 6”
Superior Product Performance
- 1. Ultra low leak rate: Integral vacuum brazing sealing, not glue bonding Helium leak rate <=1×10-10 mbar·l/s (UHV industrial standard)
- 2. Strong environmental adaptability: Resistant to chemical corrosion by plasma and corrosive gas, cyclic high temperature baking to degas, adaptive to complex vacuum process conditions
- 3. Customizable Optical Coating: We can provide single layer/multi-layer anti-reflection coating, anti-fog coating and anti-radiation coating to reduce light reflection loss and improve optical utilization
- 4. Simple installation and maintenance: standard interface for mainstream vacuum accessories in the world, convenient assembly and disassembly, no complicated maintenance
Wide Range of Application Scenarios
Our UHV viewport windows are widely accepted by worldwide customers and widely used in various high-precision industries:
- Scientific Research Surface physics, material analysis, high-energy physics, vacuum metallurgy laboratory equipment
- Semiconductor & Electronics: wafer processing, ion implanters, thin film deposition (PVD/CVD), vacuum etching equipment
- Optical Industry Laser calibration, spectroscopic analysis, optical signal transmission, photonics research
- Aerospace & New Energy: Space environment simulation equipment, Battery material test, Vacuum thermal treatment equipment
Custom Service
We provide one-stop customized services, such as non-standard window size, special flange size, exclusive optical coating, personalized material combination, etc. Send us your technical parameters, we will provide you with customized vacuum optical solutions with the support of our professional engineering team.
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FAQ
How to get product solutions?
You can tell us your needs (such as specifications, quantities, materials, drawings, etc.) by email(info@prekovar.com), phone or by submitting the form on our website.
Why Choose Us?
With over 10 years of specialized focus on Kovar/alloy processing, we master the unique challenges of this low-expansion material. Our advanced stamping techniques ensure micron-level accuracy, ideal for critical applications in electronics, aerospace, and hermetic sealing components.
