Courtesy of furnace builder “SECO/WARWICK” we have a photo of the largest vacuum furnace we at “The Monty” have ever seen. This unit is capable of loads of over 100 tons and has a diameter of 12′ (4 meters). The furnace (which was installed a few years ago at a location in California) is designed to heat treat coils for a very specialized energy application. Pretty cool looking furnace.