Tube to Tubesheet joint effect on Tubesheet thickness

[rezasme]

Hi,
I have gone through UHX but can not find the effect of tube to tubesheet joint type on tubesheet thickness calculation.
In one case I've checked below results with software:
Expanded only, expanded with 1 groove, expanded with 2 groove: same result for 3 cases 143mm

Welded (all methods including a>1.4t, t<a<1.4t): 161

Welded and expanded (all possible combination): 143

I have below questions:
1- How the joint type (weld or expand) affect the calculation? where in UHX it is clarified?

2- When we have "Strength welded plus lightly expanded" :

2-1- What is the sequence?

2-2- What is the difference between lightly expanded and expanded? Is the difference just about tube wall thinning or existence of grooves govern the identification?

2-3- Can we consider this as "welded and expanded" or it's just "welded" and expanding is not participating in load carrying?

Any comments and discussion is highly appreciated.

[rezasme]

Any knowledge sharing????????