Steam boiler is a closed vessel in which heat produced by the combustion of fuel is utilized to generate steam from water, at desired temperature and pressure. Sr.No. Particular Fire tube boiler Water tube boiler 1 Position of water and hot gases Hot gases inside the tubes and water outside the tubes Water inside the tubes and hot gases outside the tubes 2 Operating pressure Limited to 25 bar More than 125 bars 3 Rate of steam generation Lower Higher 4 Suitability Not suitable for large power plant Suitable for large power plant 5 Chance of explosion Less due to low pressure More due to low pressure 6 Floor space requirement More Less 7 Cost Less More 8 Requirement of skill Required less skill for efficient and economic working Required more skill and careful attention efficient and economic working 9 Use For producing process steam For producing steam for power generation as well as process heating 10 Scale deposition & over heating There is no water tubes, no problem of scale deposition and less problem of overheating & bursting Small deposition of scale will cause overheating and bursting of the tubes
