Lumistar Special Glass Technology Co., Ltd.
KF16 vacuum sight glass (ISO-KF16) for high-vacuum systems. Available in borosilicate, fused silica and sapphire. Compact, quick-install KF flange, optional AR coatings and custom sizes.
KF16 Vacuum Sight Glass (KF16 Vacuum Viewport)
The KF-16 vacuum sight glass (also written KF16 viewport) provides a compact, high-vacuum optical window for process observation and alignment inside vacuum chambers.
Compact and easy to fit to standard KF hardware, it delivers repeatable sealing and clear optics for inspection, spectroscopy and laser access.
First, it saves space: the KF-16 viewport fits where larger viewports cannot.
Second, it supports demanding optical work. For example, quartz and sapphire versions tolerate higher bake-out temperatures and transmit ultraviolet and laser wavelengths better than generic glass.
Finally, our engineers will recommend the best material and seal when you tell us the operating pressure, temperature and wavelength.
| Specification | Value / Notes |
|---|---|
| Model | KF16 vacuum viewport (KF-16) |
| Rated vacuum | Leak rate down to 1×10⁻¹² Pa·m³/s (typical with metal seal) |
| Flange material | Stainless steel 304 (316 on request) |
| Window materials | Borosilicate (visible), Fused silica (quartz — UV), Sapphire, BaF₂, CaF₂, ZnSe (IR) |
| Surface quality | 60/40, 50/20, 20/10 (select per optical spec) |
| Optical flatness | 1/2 to 1/10 λ (depend on material & spec) |
| Visible aperture (mm) | Ø16 (clear aperture) |
| Typical heat resistance | Borosilicate: 150–230°C; Quartz/Sapphire: higher bakeout temp (see datasheet) |
| Transmittance (typical) | Material dependent: e.g. quartz high UV; borosilicate visible (spec range 1.45–1.76 refractive index shown for ref.) |
| Outer / Inner diameter | OD: 30 mm — Visible bore: 16 mm |
| Product height | 13.5 mm (typical assembly height) |
| Glass thickness | ~2 mm (standard — thicker options available for mechanical loading) |
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Download datasheet (PDF)
