How can cast iron boiler capacity be increased?

Increasing the capacity of a cast iron boiler can be effectively achieved by adding additional sections. This is because cast iron boilers are designed modularly, allowing them to be expanded to meet greater heating demands. Each section added contributes additional surface area for heat transfer, thus enhancing the overall capacity to produce steam or hot water. This capability for modular expansion is a key feature in the design of these boilers, providing flexibility for varying operational needs.

In contrast, options describing the inherent dimensions of cast iron compared to steel do not address the capacity increase directly. Additionally, stating that capacity cannot be increased once assembly is completed overlooks the design flexibility that comes with sectional assembly. Lastly, while increasing the size of existing sections could theoretically lead to higher capacity, it would not be practical or possible in many cases; thus, simply adding sections remains the most straightforward and effective method for achieving the desired increase in capacity.