Official proceedings of the annual convention Volume 10, pt. 1916

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1916 Excerpt: ...gentlemen. Mr. A. N. Lucas: Every time our superheater units are taken out, we run a cleaner through the large flues, whether they are clogged or have been. We find there is a coating of scale on the inside of the large flues. We run the cleaner through and knock it off and we find more in there than you would imagine. It has been found that considerable scale formed on the inside. When we take the small flues out we use the same tool we are using with the hammer on the inside of the boiler and we get off all we can. We also adopted a method of placing the bands on the units. Many times they were placed by one department that did not know whether the unit would go into the flues or not. So we give them a short piece of flue to go over the band, something for the machinist to go by. The bands were formerly placed in a proper manner so as to keep the units from vibrating. We have tested this out and I think you will get results with this method. Mr. Borneman: I would like to hear something about the size of the superheater hole in the back flue sheet. Should it be the size of the flue, four and one-half inches, or three-sixteenths of an inch larger? Mr. A. N. Lucas: The flue is four and one-half inches swedge to fit the shim; practically the same as the smaller flues. Mr. Gray: As to cleaning the interior of the tubes after the unit is removed, we wash them out with about 100 pounds pressure and we get a better job. We always do it if only one pipe is removed. A Member: We wash them out. Mr. Gray: We drill the flue hole in back flue sheets a quarter of an inch bigger than the flues. We have four inch and four and a half inch, with eight inch copper. Mr. Powers spoke about welding the superheater flues. We have a little heavier flue, I think, than most people ...