What is inspected after a boiler shell is tack welded?

After a boiler shell is tack welded, the fit-up of the boiler shell is inspected to ensure that the components are properly aligned and positioned before the final welding takes place. This inspection is crucial because it verifies that all parts of the shell are meeting the necessary design specifications and tolerances. Proper fit-up ensures that there will not be any issues during the final welding process, such as gaps that could result in weak joints or improper seals. Ensuring a correct fit minimizes the risk of leaks and enhances the overall structural integrity of the boiler once fully welded and operational.

The other choices focus on different aspects. For instance, while the steel used is important for overall safety and durability, it is assessed prior to the welding process. Insulation pertains to thermal efficiency and safety after the welding is complete. Lastly, internal components are typically evaluated after the shell has been fully welded and inspected, as they require access through the completed shell for proper inspection.