A modular cast-iron heating boiler is composed of what?

A modular cast-iron heating boiler is typically composed of a number of horizontal sectional cast-iron boilers. This design allows for increased flexibility in heating capacity, as multiple sections can be combined to meet the specific thermal load requirements of a facility.

The use of sectional boilers means that each individual unit can be operated independently or in unison with others, which provides advantages in terms of maintenance and operational efficiency. If one section requires servicing, the entire system does not need to be taken offline, allowing for continual operation and minimizing disruption.

Moreover, the modular approach helps in optimizing heating performance since it can match the demand more effectively than a single large boiler. This adaptability can lead to energy savings and more efficient operation.

In contrast, the other choices do not accurately represent the modular cast-iron design. A single large boiler would not provide the modular benefit of individual sections, while a series of vertical firetube boilers and a mixture of different boiler types do not align with the definition and functionality of modular systems specifically designed with horizontal sectional cast-iron boilers.