Liquid Nitrogen Feedthroughs are engineered for the same cooling purposes as Water Feedthroughs, but with the added advantage of ultra-low temperature performance (-200°C), enabling significantly greater cooling rates. They are designed to minimize heat transfer between coolant lines and vacuum mounts, ensuring reliable performance.

To prevent ice build-up—which can be detrimental to vacuum sealing—these feedthroughs utilize double wall coaxial construction. A 0.25 inch (6.35 mm) cooling line is inserted and welded to one end of a 0.5 inch (12.7 mm) support tube. The opposite end of the support tube is welded to the vacuum mount, creating a coaxial vacuum cavity that acts as a thermal barrier, preventing condensation on the air side of the mount.

Liquid Nitrogen Feedthroughs are available in three vacuum mount styles: Del-Seal CF, ISO NW Kwik-Flange, and 1 inch (25.4 mm) Base Plate. Additionally, ISI offers individual liquid feedthrough tube kits for direct welding into custom chambers or flanges, supplied as weld tubes without fittings.

Each feedthrough is constructed with 0.25 inch (6.35 mm), type 304 stainless steel tubing, and is available with three fitting options:

Weld-tube (plain tubes without fittings)
0.25 inch (6.35 mm) Swagelok® compression fittings
0.25 inch (6.35 mm) male VCR® metal gasket seal fittings

Note: Mating VCR female nuts and copper gaskets must be purchased separately.

Industry Applications

Nitrogen-Tube Feedthroughs are widely used in industries that demand precise cryogenic cooling and high-vacuum sealing. Common applications include semiconductor fabrication, superconductivity research, cryogenic testing, vacuum coating, particle accelerators, and aerospace thermal management systems. Their ability to withstand extreme temperatures and maintain vacuum integrity makes them essential in advanced scientific research, industrial processing, and high-tech manufacturing environments.