What is a Steam Generator Boiler?

A steam generator boiler uses a single tube coil instead of many smaller diameter boiler tubes. The generator forces the flow of hot water through the tube to convert it to steam during a single pass through the coil. 


The water containing coils go around the steam generator. The furnace heats the water, circulating down through the coiled tube. While traveling down, it turns to steam as it heats, and exits the boiler in a concentrated stream at a point at the bottom of the tube.


  • It is generally less potent than a full boiler but it is easier to operate.
  • These generators are also smaller, making them more versatile when there is limited space available.
  • They are often used as auxiliary boilers because they start up very quickly, and in applications with very low load factors.
  • These boilers have a compact design, single water tube, and relatively lower water content. Consequently, they can be up and running at full power in a much shorter amount of time than larger boilers. As a result, they are useful in emergency and quick demand situations.
  • They generally cost less than larger boilers. For this reason, they may be more cost-appropriate for applications that do not necessarily require such high levels of steam.
  • They perform well at part loads and respond quickly to changes in loads. As a result, they dramatically increase part load operating efficiency.
  • The fact that they do not have pressure vessels means that in most locations, they do not require a boiler operator. 
  • A steam generator boiler is useful where it can give operational efficiency because it costs around 50% more for the same horsepower output than larger boilers.

For more information about steam generator boilers, ask our steam team here.

Sources: Superior Boiler