How are cast iron sectional boilers held together to ensure they are leak-proof?

Cast iron sectional boilers are designed with multiple interconnected sections that are held together using tie rods and bolts. This method creates a secure and stable structure while allowing for the expansion and contraction that occurs during heating and cooling. The tie rods provide tensile strength, while bolts create a compression seal between the sections, ensuring that they are securely fastened to prevent water or steam leaks. This mechanical fastening is crucial for maintaining the integrity and efficiency of the boiler system.

The other options involve methods that are not effective for this type of boiler. Welded seams, while effective in some applications, are not typically used in sectional boilers because the assembly requires the flexibility to allow for thermal expansion. Pressure fittings and pressurized clamps also don’t provide the same level of secure, leak-proof mechanical fastening necessary for the operational conditions of a cast iron sectional boiler. Thus, the use of tie rods and bolts is the most suitable and widely accepted approach for ensuring these boilers function safely and effectively.