Boiler or steam is a tool in form of closed vessel used to produce steam. Steam is obtained by heating water in the vessel using fuel. Boiler converts chemical energy into another form of energy to produce work.

Boiler is designed to tranfer heat from a heating source, usually in form of fuel combustion. Boiler is a container given water and heated, so the water boils and evaporates continuously into steam. Steam produced by boiler is used for various processes in industrial application, such as steam as the main driver of turbin, driver of tools that can move turbine blades that rotate generator, cargo pump, compressor, heater, and so on.

Boiler operation must be in accordance with the operational standart specified by boiler users or the manufacturer of boiler itself. The standart to be made will secure the safety in operation, so as to improve the efficiency of steam boiler to reduce operational costs.