Orifices and gravity hot-water heat

Dan,
I thought I was the only stupid one in the room. I feel like it now looking back at some of those older homes where I never figured out about the orifice and suffered grief.

Thanks for sharing your stupidity.

A Near Stupid Wethead Brother

This is a very large building that used to be the Nortern Electric plant. 8 plus floors and is a one pipe gravity system. It had a power plant that had 4 mains going to the top floor ceiling. Each one would split in two opposite runs. Each run would feed several feeder pipes that went down to a similare setup in the basement. At each floor were two special 'Y' one would point down the other up which would feed a large cast iron radiator. Inlet into the top of the radiator and return from the bottom of the radiator into the single pipe.