Older bent water tube designs were originally atmospheric designs that have been modified to accommodate forced draft firing. The Unilux 5 pass boiler is a true forced draft design encased in a heavy duty insulated steel housing. Industrial grade housing panels are well encased in a heavy duty insulated steel housing. Industrial grade housing panels are well insulated with 3” of high temperature fiber wool. The entire casing, when completed allows for up to 5” water column pressure. The housing is further insulated with a steel jacket employing a 2” air insulator space between the inner and outer panels for maximum insulating effect. The front and rear boiler walls are made with our exclusive 3 tier process. First a 4” layer of insulating refractory is poured, second a 1” layer of high temperature fiber board installed and third, a 4” layer of 2700 deg. F refractory is poured. All this is stayed with stainless steel anchors closely spaced and welded to the outer steel housing. Operating radiant losses are calculated at ¼ of 1% of maximum input. Larger boilers (model 2000 and up) have grade 12” and 10” walls for ultimate dependability.

Unilux features large volume down comers (one for water designs and two for steam designs) totally isolated from the fireside to provide maximum positive circulation within the pressure vessel. Water flow resistance is minimal, as such, external circulating devices are not required with Unilux design.

Both the fireside and water side are easily accessed for inspection and maintenance through strategically located ports on the assembly.

Unilux boiler tubes are no less than 1½ SA178A, electrical resistance, welded carbon steel high quality construction. Tubes are generally fitted with a precision machined, tapered ferrule that is driven into the machined boiler drums. There is no welding or rolling required. Tube replacement, if required is easily achieved without major disassembly of the boiler.