I have a case where there is 36.o m cryogenic tank. Number of big bore 10", 16" lines run parallel to tank shell and get connected to nozzles on tank roof . The nozzles are placed on circle of 12.0 m radius on tank roof. Tank temperature is -65 Deg. C.
The radial contraction of nozzles towards tank centre is considerable and whether needs to be considered in the analysis ?

What is normal practice ?

For shell nozzles of tanks, especially on lower tank shell course, some engineering companies neglect radial contraction.

ANY OPINIONS PLEASE.

Of course you should account for the radial contraction. Not only on the roof, but also on the lower courses. "Some engineering companies" appear to be making an error, in my opinion, by neglecting this phenomenon. Even if you have a flat-bottom tank resting on grade, the bottom plates would contract in your example essentially the same amount as the top plates. (Cryogenic tanks are normally placed on large insulating pads to isolate them from the ground temperature.)

I answer with the following question why would the metal not expand or contract in regards to its temperature?