Formed stainless steel bellows for ultra-high vacuum applications

The TE-VSC group at CERN is looking for formed stainless steel bellows for ultra-high-vacuum applications. The bellows shall be produced with a wall thickness of 0.15 mm.

The requirement is for a few hundred bellows in various unit lengths comprised between 50 mm and 150 mm. The bellows outer diameters are between 150 mm and 300 mm.

Some of the bellows will be operated at cryogenic temperature (down to 60 K). The convolutions of these bellows shall be produced in 1.4441 grade stainless steel which CERN can supply. For the bellows that will be operated at room temperature, the use of 1.4404 grade stainless steel is acceptable.

The collars at the bellows extremities have to be machined from multi-directionally forged 1.4429 grade stainless steel. The fully machined collars can be supplied by CERN, or CERN can supply the raw material for the collars which the firm can then machine and weld to the bellows.

The drawing in annex shows a typical example of the type of bellows we are looking for.

Delivery of the bellows is foreseen for the second half of 2021 / first half of 2022.

We would like to get in contact with interested suppliers that:

•   Have in-house experience with the manufacture of formed stainless steel ultra-high vacuum

  bellows;

•   Are familiar with calculations according to EJMA standards or EN14917+A1.