I do recall some computer equipment that had helium in
the enclosure. At least
that's what the labels said.
I have a DDC 7301 drive (same manufacturer as Guy's, but different model),
and it is definitely filled with helium. Well, it was filled with helium
30 years ago ...
The DDC maintenance manual says it requires oil-free 99.995% pure helium.
The preventive maintenance procedure indicates that the helium tank is
good for about 6 months (dropping from 2200psi to 300psi).
James Markevitch