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Out of Chamber Electron Beam Welding

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Conventional in-chamber EB welding presents the challenge and limitation that the entire assembly for welding must fit within a vacuum chamber, providing the required environment and radiation protection. The cost of such welding machines can be prohibitive for large assemblies and limits the process to modest sized weldments.

For applications which are too large to be constrained by a vacuum chamber TWI offers out-of-vacuum-chamber local vacuum welding; this technology is of interest for welding assemblies such as pressure vessels and offshore wind tower foundation structures.

TWI is active in out-of-chamber developments to allow welding of very large assemblies in a cost effective manner.


  • Design, prototyping and testing of local vacuum sealing systems
  • Welding in a reduced-pressure vacuum
  • Welding out-of-vacuum
  • Use of local travelling vacuum seals
  • Use of local static vacuum seals
  • Reduced kV guns for x-ray minimisation
  • Weld procedure qualification and testing
  • Market techno-economic analysis

Applications and Benefits

  • High productivity welding
  • Thick section welding
  • Power industry – vessel welding
  • Oil & Gas - line pipe welding
  • Offshore power - foundations welding

For further information please see Joining Technologies or email

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