Re: Boiler design question

Clearly there are others with a great deal more knowledge than I have, but I can answer at least part of your question. Tubes or flues are intentionally thinner than any other part of the pressure vessel (boiler) to maximize heat transfer. Because they are thinner, corrosion will result in a leak sooner than on any of the thicker parts of the boiler. Scale build up on the tubes will also reduce heat transfer causing the tubes to become hotter, which can in some cases lead to failure. The tubes or flues are subject to a great deal of expansion and contraction which can lead to leaks or failure at the flue sheets.
As to crown sheets, along with the side sheets and door sheet are subject to a great deal of expansion and contraction due to potentially rapid changes in the size or intensity of the fire. Stay bolts can become loose in the sheets and the sheets sometimes develop cracks radiating out around each stay bolts due to these repeated expansion and contraction forces. Side sheets also can deteriorate on the fire side at the level of the fire bed on coal burners and behind the brick work of oil burners due to corrosive aspects from the fuel itself. My brain is now empty....



Edited 1 time(s). Last edit at 03/01/2010 10:17AM by J.B.Bane.