The expanded portion of a tube is that part which is radially expanded outward within the tube hole. When the tube is expanded, it is also pressed into the tubesheet.
Some tubes are welded into place and this value may be zero. The maximum this value can be is the thickness of the tubesheet. A fully expanded tube-tubesheet joint can reduce the tubesheet-required thickness.
For ASME Tubesheets Only
In most cases, tubes are not fully expanded through the thickness of the tubesheet. There is a typical distance of a few millimeters that is not expanded.
Select the Use Alternate Tube Expansion Dimensions check box, to enable the Expansion Start Dimension from Channel Side and Min. Distance from the Shell Side the Expansion should Stop fields in which to enter the dimensions.
When given the dimensions, the expanded length of the tube in the tubesheet can be computed in cases involving both the corroded and uncorroded conditions.
The dimensions are measured from the face of the tubesheet in the new condition.