CYLINDRICAL form and riveted or welded together. The shell ends are closed with the endplates.Grate It is a platform in the furnace upon which fuel is burnt and it is made of cast IRON bars.Bars are arranged such that AIR may PASS on to the fuel for combustion.Area of the grate on which fire rests in a coal or wood-fired boiler is called grate surface.MountingsThese are different fittings and devices which are necessary for the operation and safety of a boiler. Usually, these are mounted over boiler shellIn accordance with Indian boiler regulation following mountings are listed belowSafety valvesWater level indicatorsPressure gaugeSteam stop valveBlow-off cockManholeAttachment for inspector's test gaugeMud holes or sight holesRefractoryA heat insulation material such as fire brick or plastic fire clayIt is used for such purposes as lining combustion chambers.Other Boiler terms:Boiler AccessoriesThey increase the efficiency of the boiler and form an integral part of the boiler. Commonly used accessories are as followsFeed pumpeconomizersuperheaterair preheatersteam separatorsteam trapFurnaceIt is a chamber formed by the space above the grate and below the boiler shell, in which combustion takes placeIt is also called fire-boxWater levelThe level at which water STANDS in the boiler and space above it is called steam space SettingThe primary function of the setting is to confine the heat to the boiler and form a passage of gases.It is made of brickwork and may form the wall of the furnace and the combustion chamber.