In a firetube boiler, beading the tube ends helps to achieve which objective?

In a firetube boiler, beading the tube ends is primarily intended to help prevent overheating of the tube ends. This technique involves forming a bead at the end of the tubes, which can create an expansion joint that accommodates thermal expansion and contraction. The bead also helps in directing the flow of the flue gases more effectively around the ends of the tubes, improving heat transfer and reducing the risk of hot spots that can lead to overheating.

Additionally, by controlling the temperature more effectively at the tube ends, beading can help extend the overall life of the tubes by preventing damage that would result from excessive heat stress. This is crucial in maintaining the operational efficiency of the boiler and ensuring safety during its operation.

The other options do not accurately reflect the primary objective of the beading process in a firetube boiler. Beading does not eliminate the need to expand the tubes into the tubesheet; rather, both processes are often used in tandem for optimal performance. Likewise, while beading contributes to leak prevention, it does not entirely stop leakage on its own; proper tube expansion and sealing techniques are also essential. Regarding seal welding, it is not a mandatory subsequent step after beading, although some applications may choose to follow up with welding for additional strength or sealing