This book, Hoffman Venting Valves for Every Purpose, was from the Hoffman Specialty Co. in 1918. It includes a lot of information about Hoffman valves for heating systems. You'll also find a discussion of Hoffman's Equalizing Loop, which came before their Differential Loop. Thanks to Frank "Steamhead" Wilsey for finding and sharing this document with us.
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.