RBI Water Heaters, a Mestek Company: Symmetrical Fire Tube Boiler
The FlexCore 1.5 stainless steel, symmetrical fire tube boiler achieves 95.1 percent Air-Conditioning, Heating, and Refrigeration Institute (AHRI)-certified efficiency and utilizes a precisely temperature-balanced FlexCore heat exchanger, which provides high efficiency and maximum durability. According to the company, the balanced symmetrical design creates a single flexcore heat exchanger. In essence, the entire tube sheet can move like a piston; the upper tube sheet design is that of a diaphragm that absorbs the stresses from this piston-like motion. The result of this design is that water temperature differences up to 100°F can be accommodated with no detrimental effects.