A steam generator is an apparatus in which feed water is first heated to the boiling point and then evaporated. The generated saturated steam is collected in the steam drum above the water level and discharged. The heating is usually done by a u-tube bundle plugged-in the lower part of the shell, which is connected to the heat source. The steam generator has nozzles all the necessary equipment for safe operation like safety valve, vacuum breaker, level probe, conductivity electrode, pressure and temperature indicators and limiters, desalination and blowdown. Usually, at least one show hatch is included, via which one can visually inspect the interior of the shell and the tube.