Corne,

I think the flanged channel bolted to the back of the tubesheet is a configuration that the code rules do not address. Is it feasible to reduce the outside diameter of the tubesheet below the bolt pcd and have another wn flange on the channel side to clamp the tubesheet? This is an easier configuration to model.

ps The two .PVI files do not appear to be available for download and cause an error when attempted.