Built for performance and longevity with symmetrical fire tube technology, boiler and water heater manufacturer RBI has brought a new high efficiency fire tube boiler to market — the FlexCore 1.5. The boiler achieves 95.1% AHRI certified efficiency and utilizes a precisely temperature-balanced flex core heat exchanger, which the company says provides the highest efficiencies and durability beyond that of any competitive fire tube boiler on the market.
The maximum uniform heat transfer is obtained through the flex core heat exchanger’s design. Officials explained that this balanced symmetrical design creates a single flexcore heat exchanger. In essence, the entire tube sheet can move as 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 degrees can be accommodated with no detrimental effects.
The company also claims that the FlexCore 1.5 essentially “scrubs” every last bit of heat out of the combustion gases, resulting in unparalleled efficiencies in a compact footprint while absorbing all expansion and contraction, with no stress on the tubes.
Inside the symmetrical array, each tube has been formed in a patented shape that is compressed and dimpled, such that very high gas side film coefficients are created. This results in very high efficiencies in a compact design and allows condensate to easily flow out without any chance of pooling, ensuring low corrosive effects. Further, the water is introduced and removed from the heat exchanger in such a manner as to provide perfect temperature symmetry among the tubes, according to RBI. The FlexCore Fire Tube is ASME certified for water heating and space heating.