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Cryogenic Fluid Feedthroughs

Silhouette of dual cryogenic VCR fluid feedthrough

Cryogenic Feedthroughs - Swagelok + VCR Fittings

Cryogenic service fluid feedthroughs are used to deliver gas and/or coolants, such as Liquid Nitrogen LN2, into high (HV) and ultrahigh (UHV) vacuum systems. Feedthroughs are available with single or dual 1/4 inch tube supply lines. Supply lines are thermally insulated by a 1/2 inch coaxial support tube, which creates a vacuum gap around each supply line. Cryogenic feedthroughs are terminated with Swagelok standard compression (swaging) fittings, or VCR metal-gasket-fitted, ultrahigh-vacuum-rated fittings.

The Swagelok® fittings products a demountable, gas-tight cold-formed (swaged) mechanical joint between a tube's OD and the ferrules housed inside each fitting.  Tube finish, temper, and wall thickness are all critical parameters for making reliable, gas, and vacuum-tight seals.

The VCR fittings are zero-clearance, demountable UHV compatible mechanical joints produced by crushing a deformable metal gasket between two mating and polished fitting gland faces.  Fitting gland finish, and metal gasket temper are critical parameters for making reliable, gas, and ultrahigh vacuum seals.

These are general-purpose, non-cryogenic, tube feedthroughs used for gas and/or fluid coolant delivery into high and ultrahigh vacuum systems.

Fluid Feedthrough Material Specifications
  • CF Flange / Tubes
  • VCR Fittings

304 Stainless Steel
316 Stainless Steel

Fluid Feedthrough Vacuum Range Specifications
Vacuum Range  
  • UHV, Ultrahigh vacuum
  • HV, High vacuum

1x10-13 Torr
1x10-8 Torr
Fluid Feedthrough Temperature Range Specifications
Temperature Range  
  • CF Flange Mount
  • ISO KF Flange Mount
  • VCR, Fitting
  • VCR SS, 316L Gasket
  • VCR Cu, Copper Gasket
  • VCR Ni, Nickel Gasket


* Overall assembly ratings must be adjusted to that of the lowest-rated component.