Generally, Tank Settlement dispacement is combined with Operating Load case and stresses generated are compared with Expansion Stress Range.
Load case considered are as follows,

L1 - W+P+T+D1 (OPE)
L2 - W+P (SUS)
L3 - L1-L2 (EXP)

In addition to the above, is it required to combine displacements due to tank settlement with a sustained condition and check the gernerated stresses with WxSh (Sustain Stress Allowable).

L4 - W+P+D1 (SUS) (Is this additional load case reuired???????)

Regards

Answer is :
1.no
2.no, but you may consider W+P1+D1 (OPE) for Tank nozzle loads. Sometimes it will result in loads bigger than for W+P+T+D1 (OPE)

Thanks Danb for your reply.

But still I doubt wether it is really required to do load check?

If someone can throw more light on above subject, its higly appreciated.

You may do as follows:

First do this check, then if you discover that there is no problem, you can delete the load case.