boiler expansion tank placement
I have an older 20 to 25 year old Weil McLain boiler. I had my house broken into and they stole my copper plumbing. I replaced all the plumbing but I don't know where the expansion tank goes. It looks like the order is - on the inlet side, shut off valve, pressure regulator then tee into the boiler and on the other side of the tee the expansion tank. There is no other inlet available on the boiler. I was told the expansion should be on the return, but the boiler is piped in black pipe, the inlet was all copper. I don't see any other place to install the tank. If it makes any difference, all the radiators have automatic air relief valves. I don't have any zones. Any help would be appreciated.