Dear SK,

Your first post illustrates the difficulties associated with trying to check nozzles for hydrotest case. Another important aspect is what allowables should be used for the various checks for the nozzle.

If you computed hydrotest pressure as 1.3 * design pressure or 1.3 * MAWP then the equipment should be ok during hydrotest test. This is just a function of the factor of safety built in to code allowables.

Also note that, ASME Sec. VIII Div. 1 code does not explicitly state that you have perform the calculation under hydrotest condition. Neither does it prescribe the allowables for HT case.

But, I think a reasonable approach is to check shells and heads under hydrotest condition and making sure the nozzle does not control the MAWP of whole vessel (specially if you choose 1.3* MAWP as HT pressure).