  This contribution reports the design of the main components used to
interconnect SRF cavities and superconducting focusing lenses in the SSR
Cryomodule beamlines, developed in the framework of the PIP-II project at
Fermilab. The focus of the present contribution is on the design and testing of
the edge-welded bellows according to ASME Boiler and Pressure Vessel Code. The
activities performed to qualify the bellows to be assembled in cleanroom, for
operation in high vacuum, cryogenic environments, and their characterization
from magnetic standpoint, will also be presented.
