interesting picture....not sure if there's an outlet at the bottom to the hoses underneath - I can only guess so - therwise it wouldnt work.

Thanks

But if I can rephrase/refocus....is there a check valve in these lower reservior tubes so that they only draw form the reservior?

If not, what is the thinking between the larger lower and upper (smaller) pipes?
Are the upper ones in case of a "steam/boiling" event - hence they come from the top of the system, but most of the time the lower pipes draw and suck any 4% system expansion.
(PS 4% expansion from 10L = 400mls)