Operation
Although the maintenance of the water level is not so critical as with water tube designs, it should not be allowed to fall too much as overheating of furnace and combustion spaces leads to catastrophic failure due to component collapse. The content of the boiler is then expelled via the furnace door.
Similarly , although water treatment is not so critical scale must not be allowed to build up which can lead to overheating of material
Authors Note
Although package boilers of this design are fairly robust it should not be forgotten the potential for danger a poorly maintained unit can be.
The author carried out a supposed routine inspection on one such unit. Opening the upper manhole revealed that the unit has been 'wet layed' with water left at normal working level rather than being pressed up . Severe pitting was present at and just below the water level.
The lower man hole door beneath the furnace was opened after draining the water. Heavy wastage could be seen later measured at 60 % of the shell plating with pitting on top of this. Evidently no oxygen scavenger, such as Sodium Sulphite, had been added before laying up.
In this condition, operation at full load would almost certainly have led to catastrophic failure.
