The Imico System was a rare vapor heating system. "There is no air valve at the radiators in this system and no trap on the return end of the individual radiator. Vacuum is maintained in this system by the Dewey tri-duty air and vacuum trap, which is a combination of the Dewey quick vent air valve and the Dewey vacuum valve." Here is some information about it from The Heating and Ventilating Magazine.
Here is the original Installation and Operating Instructions and Parts List for The H.B. Smith Company's Oil Fired Cast Iron Hot Water Boilers (No. OHB-13W). This is esti...
The Henry Ford Museum in Dearborn, MI has an interesting hot-water heating system. Take a look at the radiators below. They are from the Shaw-Perkins Manufacturing Compan...
We estimate that this cast-iron boiler catalog from The Peerless Heater Company in Boyertown, PA is from the 1980s or 1990s.