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KF Vacuum Viewport

The KF Vacuum Viewport provides reliable optical access for high-vacuum systems using standard KF flange connections. Available with borosilicate glass, fused quartz, sapphire, CaF₂, or BaF₂ windows, it offers excellent optical performance for vacuum chambers, laser systems, spectroscopy, and scientific research.

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Technical data

KF Vacuum Viewport Overview

The KF Vacuum Viewport is designed to provide dependable optical access for high-vacuum systems while maintaining reliable vacuum integrity. Manufactured with a precision stainless steel KF flange and a selection of premium optical window materials, it offers excellent optical transmission, mechanical stability, and long-term performance.

Compatible with standard KF (NW) vacuum fittings, this viewport enables clear visual inspection, laser transmission, spectroscopy, and optical diagnostics without compromising vacuum performance. Multiple window materials are available to meet different wavelength, temperature, pressure, and chemical compatibility requirements.

Suitable for laboratory research, semiconductor manufacturing, vacuum coating, laser processing, analytical instruments, and industrial vacuum equipment, the KF vacuum viewport combines easy installation with excellent sealing performance.

KF Vacuum Viewport — Technical Data

SpecificationDetails
Product NameKF Vacuum Viewport
Flange TypeKF Standard
Body MaterialSS304L / SS316L Stainless Steel
Window MaterialsBorosilicate, Fused Quartz, Sapphire, CaF₂, BaF₂
Standard SizesKF16, KF25, KF40, KF50, KF63, KF80
Vacuum LevelRough Vacuum / High Vacuum
Leak Rate≤1 × 10⁻⁹ mbar·L/s (Helium Tested)
Operating TemperatureDepending on window material
Sealing MethodCentering Ring with O-Ring
O-Ring MaterialViton, Silicone, EPDM (Optional)
InstallationVacuum Chambers, Optical Systems, Laboratory Equipment

Optical Window Material Selection

Window MaterialSpectral RangeMain AdvantagesTypical Applications
BorosilicateVisibleCost-effective, excellent clarityGeneral vacuum observation
Fused QuartzUV – NIRExcellent UV transmission, thermal stabilityUV optics, lasers
SapphireUV – IRHigh hardness, pressure resistanceHigh-pressure and laser systems
CaF₂UV – IRWide spectral transmission, low absorptionUV optics, spectroscopy
BaF₂UV – Mid IRExcellent infrared transmissionFTIR, infrared optical systems

KF Vacuum Viewport— Drawing

Material Comparison

PropertyBorosilicateQuartzSapphireCaF₂BaF₂
Visible Transmission★★★★★★★★★★★★★★★★★★★★★★★★★
UV Transmission★★☆☆☆★★★★★★★★★★★★★★★★★★★☆
Infrared Transmission★☆☆☆☆★★★☆☆★★★★☆★★★★★★★★★★
Hardness★★☆☆☆★★★☆☆★★★★★★★☆☆☆★☆☆☆☆
Thermal Stability★★★★☆★★★★★★★★★★★★★☆☆★★★☆☆
Pressure Resistance★★★☆☆★★★★☆★★★★★★★★☆☆★☆☆☆☆
Recommended UseGeneral VacuumUV & LaserHigh PressureUV/IR SpectroscopyFTIR & IR Optics

KEY FEATURES

Multiple Window Materials:

Available in borosilicate, fused quartz, sapphire, CaF₂, and BaF₂.

Excellent Optical Clarity

High-quality optical windows provide clear observation and efficient light transmission.

Reliable Vacuum Sealing

Precision KF flange ensures dependable leak-tight performance.

Wide Spectral Compatibility

Window materials support applications from ultraviolet to infrared wavelengths.

Corrosion-Resistant Construction

Stainless steel body offers excellent durability in demanding environments.

Quick Installation

Standard KF flange design allows fast assembly and maintenance.

Custom Manufacturing Service

We provide tailor-made solutions according to drawings or technical requirements.

TYPICAL APPLICATIONS

FAQ

A:A KF vacuum viewport is a vacuum viewing window designed with a standard KF (NW) flange, providing optical access while maintaining a reliable vacuum seal in laboratory and industrial vacuum systems.

A:Standard sizes include KF16, KF25, KF40, KF50,KF63,KF80. Other custom sizes are available upon request.


A: Yes. Anti-reflective (AR), infrared, UV-enhanced, and other specialized optical coatings are available depending on the window material and wavelength requirements.


A:Yes. Fused quartz, sapphire, CaF₂, and BaF₂ windows are suitable for many laser and optical applications depending on the operating wavelength.

A: Yes. We also manufacture CF viewports with fused quartz, fused silica, sapphire, ZnSe, CaF₂, BaF₂, MgF₂, and other optical materials for specialized applications.

Need Custom KF Vacuum Viewport Solutuions?

Send us your drawings or technical requirements for fast quotation and engineering support.