Exhaust gas and auxiliary boilers are used to generate thermal oil or steam – for example, for heating or cleaning tanks, preheating HFO, producing drinking water or heating water and living areas. Today, steam turbo-generators are also used to generate electricity for very large engines. 

Steam or thermal oil is required on seagoing vessels to heat the heavy fuel oil to a temperature of 130 to 140°C. The heated exhaust gas from the engines (exhaust gas boiler) acts as a source of energy for generating this steam or thermal oil. Other auxiliary boilers are fired with oil or gas.

A large number of valves are necessary to operate the boiler:

• Safety valves – for protection against excessive pressure
• Pressure-regulating valves – for maintaining a constant pressure
• Pressure reducing valves – for reducing pressure
• Temperature control valves – for controlling temperatures
• Steam traps – for separating condensate from steam
• Feedwater control valves – for controlling levels

Stop valves, drain valves, dump valves, check valves, strainers and sight glasses made by ARI are also suitable for these applications.