They are tested at the factory and retested by Chris' Coffee. The boiler pressure will need no adjustment, but because the brew pressure of a rotary espresso machine is dependent on inlet pressure, the pump may need some minor tweaking. It comes with setup instructions that will get you started;
Chris' Coffee Service FAQs also documents
How to adjust rotary pump pressure and it's been discussed in the forums too:
Brew pressure adjustment on Quickmill Vetrano.
BTW, thanks to Bob Craig's reminder, I've changed the defaults for HB's search to more intuitive settings that are more consistent with other search engines (specifically "and" for terms, "posts" as the result type, and a longer text excerpt).