What is a common characteristic of Horizontal Return Tubular Boilers?

Horizontal Return Tubular Boilers feature fire tubes as a fundamental characteristic. In this boiler design, hot gases from combustion pass through tubes that are submerged in water, which allows efficient heat transfer and steam generation. The fire tube arrangement facilitates effective warms of the water as the gases circulate within the tubes, enhancing the overall efficiency of the boiler.

While vertical installation can occur with some boiler types, Horizontal Return Tubular Boilers are primarily designed for horizontal operation. The design also includes multiple passes for combustion gases, which significantly improves heat exchange efficiency. Furthermore, while they do have some steam space, it is not as prominent as in other boiler designs. Hence, the presence of fire tubes is the most relevant characteristic that defines Horizontal Return Tubular Boilers.