The ICAVI Hybrid Boiler (ICFC/ICFB) aims to meet the market demand for medium-sized steam generating units, operating in various pressure and temperature ranges, with high thermal efficiency and low operating cost, having as its basic characteristics the construction of a two-passes body in the circuit of gases, with expanded tubes, burning fuel through a reciprocating grate, with a furnace and post-burning chamber lined with refractory bricks, to ensure complete combustion. The great difference of ICAVI Hybrid Boilers is its robust design that allows sudden variations in the steam flow without changing the pressure, thus giving more reliability to the processes, as all the equipment in the set operates according to the automation adjustment.