2 expansion tanks on 1 system ?

Special_K

I am laying out 2 radiant systems in one house. We are using 2 water to water geo units. One for the east end and one for the west end. There will be an expansion tank on each system. They are installing an emergency generator that cannot handle the geo units so we are installing a mod con boiler to handle the domestic hot water and serve as the hot water source via 2 injection circs. when on the generator. My concern is that when we pipe in the injection from the boiler to the 2 systems we will have 2 expansion tanks in to different locations in the system. Wondering what, if any problems that may cause? I am set up pumping away from the expansion tanks in each system.

DanHolohan

Two points of no pressure change

Check out the attachment from Gil Carlson. Two pages. Sorry they're not combined into one PDF.