Flexibility for Tank roof nozzles

Dear all,

In case of using flexibility for the nozzle connected on the roof of the tank, can I go for PD 5500 in CAESAR II. As the tank roof is of conical shape I am in a dilemma that whether I can go for it or not as PD 5500 is used for spherical curvatures. I got stuck in a situation that unless I add some flexibility my nozzle cannot be cleared.

Regards,
vishwa

You are really outside the scope of PD-5500. I suggest getting someone to look at this from an FEA point of view, to determine the nozzle flexibilites. Anything else you do will be a guess, and if it fails, you're going to be in the "hot seat". It is better to play it safe at this stage and get good numbers.