We are building out a room in the basement, and there is a discontinued steam pipe in the ceiling directly above where we would like to add a radiator. Is there a way to plumb a steam radiator so that it will work at or below the level of the boiler, and with a 7′ vertical drop in the steam line?
The steam pipe is not the problem. You have to have some way to get the condensed water back to the boiler. And I assume on your system it occurs by gravity, so the radiator has to be above the piping.