In a gravity hot water system, the hottest water is near the top of the horizontal main and tends to travel first to the upper-floor radiators. Mr. Honeywell, in 1909, patented this invention to help balance these systems. With Honeywell's tees in place, hot water would have to fill the entire pipe before any water would enter the radiators. The hot water had to slide under that internal cuff inside the tee to get to the radiators, so all the radiators heated at the same time. Beautifully simple!
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.