Bryan Boilers has released its RV Series Water Boilers, featuring its Flexible Water Tube design. Bryan's flexible tube design eliminates the possibility of damage from "thermal shock." The tubes are easily removable and replaceable without welding or rolling. With a compact water tube design, the overall size of the unit is less than most other types of boilers, yet maintains 5 sq. ft. of heating surface area per hp. Needing only 32" for tube removal, and on only one side of the boiler, the RV Series boiler occupies very little space in the boiler room. The units also feature positive internal water circulation, multi-pass flue gas travel, easy accessibility of furnace and tube area, thermal blend water return and a water-cooled combustion chamber. These RV Series boilers provide an operating efficiency of 83% or better. Bryan Boilers.