Boiler tubes that are 2 inches outside diameter or greater must project into drums or headers at least how many inches?

Boiler tubes that have an outside diameter of 2 inches or greater are required to project into drums or headers by a minimum of 5/16 to 7/16 inches. This specification ensures a proper seal and fit, which is crucial for the efficient operation of the boiler system. The projection helps to accommodate thermal expansion and contraction as well as providing structural integrity to the connection between the boiler tubes and the drums or headers.

Ensuring that the tubes project within the specified range prevents issues like gas leakage, which can lead to inefficiencies or safety hazards. A projection that is too short might not adequately support the structural needs or allow for proper sealing, potentially leading to system failures. Thus, adherence to this guideline is critical for maintaining safety and functionality within a boiler system.