Is the longitudinal joint the strongest part of a boiler?

The longitudinal joint is not the strongest part of a boiler because it typically connects two sections of the boiler shell in a longitudinal direction, which can be a point of weakness compared to other structural components. Strength in a boiler often resides in the design of other joints and structural elements, such as circumferential joints, that are designed to withstand the internal pressures more effectively.

Boiler design and construction must ensure that all joints are robust, but the nature of how pressure is distributed inside a boiler indicates that certain joints, particularly those that encircle the vessel, provide more strength against the forces exerted by the pressurized steam and water. Therefore, considering the typical stress distributions and engineering practices, it is accurate to state that the longitudinal joint does not share the same level of strength as other components of the boiler system.