This part of the pressure vessel was replaced due to the deteriorated condition of the existing piece, having been over-rolled, cracked and welded through the bridges repeatedly over the years. We could have used the original front tubesheet as is, but the amount of work it would have taken to keep it serviceable would be frustrating and tedious.
Thanks also go to Nathan Osborn who measured the original and generated the cut pattern and drilling plan into AutoCAD. During the Fall work session Nathan brought up a printout of the tubesheet patch in full size, which we matched to the existing piece to verify accuracy.
Section ready to be loaded for the trip north.
The tubesheet will come up to Portola in the Spring for the work session, April 5th-10th. Until then it's ensconced in the garage, tucked out of the way. It will be welded in after the boiler is completely scaled out inside, and we are sure that most of the work in the shell interior is complete. With the lower portion of the sheet removed access to the water space is much easier than dropping in through the dome, at least for us older chunkier individuals!
For now I wish everyone a happy and prosperous 2010. Please continue to follow our progress here and on our Facebook page, for those of you so inclined. We are over 200 "fans" so far and growing fast! - JCA