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Compression fitting of thin-walled tubes

Compression fittingcryogenicsThin-walled tubes


The new compression fitting is capable to join thin-walled tubes. It consists of two special stainless steel joints (a weld adapter and a sealing insert) that tighten the flared edge of the tube. In particular, the design of the compression fitting relies on the elastic deformation reserve of the conical edge of the sealing insert.

Technical features

The fitting of thin-walled metal tubes relies on compression forces acting on the tube to be joined: in particular, the elastic reserve of the device is capable to compensate the deformation due to thermal expansion of the materials at high temperature. Typical applications concern the cryogenic plants where the use of thin-walled tubes reduces the heat losses. Another application is related to the joining of Pd-permeator tubes used for the separation of ultra-pure hydrogen from gas mixtures.

Possible Applications

  • Compression fitting of thin-walled tubes in cryogenic applications;
  • Compression fitting of thin-walled Pd-permeator tubes used for the production of ultra-pure hydrogen.


  • Capable to ensure the tightness of the joining also in presence of the expansion of the thin-walled tube during heating at high temperature;
  • Devices applicable for joining materials having low ductility and not capable to withstand large plastic deformations;
  • Capable to join thin-walled tubes having irregular geometry (i.e. not uniform thickness, irregular circularity).