We designed Riser pipe nozzle as per API 650 Table 5.7a
Unfortunatly, there is some external load occured.
So, we need to perform additional analysis for external load.
However, TANK didn't consider Table 5.7a. So, I trying to FEA using NozzlePRO.

But, NozzlePRO cannot perform analysis for sauare nozzle pad and uneven square pad.

Is there any other good experience or method to analyze this?

Hello marionetking

Normally, one would use the function in TANK to perform that analysis in accordance with Annex P. TANK can analyse nozzles with applied loads. With regard to the square pad, I think the only way of accommodating this problem is to treat it as a equivalent round pad.

Hello Ray

Thank you for prompt reply.

If the round pad is not enough strong, should I perform FEA using other tools such as ANSYS?

Hi marionetking

In my opinion, doing FEA is not really necessary. If you inscribe a circle inside the square outline of the pad, that should be sufficient. The wall of a storage tank has a very large diameter to thickness ratio making it very flexible. The riser if well supported should not be too much of a load on the shell, and the thermal movements should be accommodated by the fairly flexible shell. Just do a simple API 650 analysis with the round pad I suggested above.

That is my opinion.

Hi, Ray

Thank you for your kind opinion.

Originally, it should be sufficiently reinforced.

Actually, our piping team forgot to add support on the riser pipe about thermal expansion and reaction force.

Anyway, all that's left to do is discuss internally.

Thank you.

Hi marionetking


So, I assume you have now sorted out the problem. Engineering is not an exact science. That is why fairly large margins of safety are often applied. Even FEA has built-in assumptions.