When rolling and expanding tubes, how far should they extend?

When rolling and expanding tubes in the context of high-pressure boilers, it is essential for the tubes to extend beyond the header or the shell to ensure proper sealing and to accommodate any necessary thermal expansion during operation. The correct choice indicates that the extensions should be even for a range of distances: 1/4 inch, 1/2 inch, and 3/4 inch.

This method allows for flexibility in the installation process, ensuring that tubes can be adjusted as needed based on specific design requirements or conditions found during installation. This approach provides a balance between stability and adaptability, preventing issues such as leakage or thermal stress points that could occur if the tubes were all uniformly the same length, potentially leading to improper fit.

Furthermore, having a range of extensions allows for easier alignment and proper thermal contraction/expansion without risking damage to the tubes or the associated headers. In high-pressure boiler systems where safety and efficiency are paramount, ensuring that the tubes are rolled and expanded correctly with appropriate extensions is a critical aspect of boiler tube installation and maintenance.