The feedwater was fed into the to the feed water collector, at the lower end of the tubes, by means of an automatic feedwater controller.
The heating surface
in the boiler consists of a set of continuous tubes running to-and-fro over the furnace. The steam generated in the tubes passes upwards into the steam
collector, carrying much water with it, but the water is separated by baffle
plates in the steam collector drum. The carried over water returns to the water
collector through vertical pipes, down-comers, at the ends of the steam
The water level height during full steam operation was about the middle of the
water tube bank.The boiler's steam outlet was always provided with a pressure
reducing valve that dried the steam since all remaining water evaporated at the
Belleville boilers worked quite well at pressures between 12
and 16 bar, but false water level readings was a huge problem.
Later Belleville water tube boiler always had an economizer on the top.