Ian Malcolm wrote:
I guestimated the pressure with info from the Fermilab website where
they were getting 8 PSI differential using ordinary vacuum cleansers,
some on suck, some on blow to clean out a *really* expensive bit of high
tech kit. http://www.fnal.gov/pub/today/NuMIhorn.html

From the website:

"It takes well over a year to build one, and I'm glad we were able to
fix it without breaking it."

nice thought!