I'm inserting a 1/2" od nozzle into one side of an rectangular vessel. The rectangular vessel passed with a wall thickness of 5/16" with reinforcement.
When using the nozzle program, the choices for shell type don't include rectangular vessel. If I use the welded flat head selection, the vessel wall thickness doesn't pass at 5/16", but the nozzel is fine.
If I select a cylinderical shell with the ID of the largest side of the rectangular vessel, it will pass.
Can you give any guidance on this issue in reguards to the program?

Marc,

To do this you must first determine the required thickness of the rectangular vessel. The rectangular vessel module provides a stress based evaluation of non-circular (and the circular one) vessels listed in Appendix 13. Determining the required thickness will take a few iterations.

Once you have settled on a required thickness, model the nozzle as usual using the welded flat head option. This will clue the program in on the fact that your nozzle is welded into a flat surface which gives you the 1/2 area required bonus. On the last tab of the nozzle input there is a check box for entering required thicknesses. Check the box and enter in the uncorroded required thickness of the rectangular vessel. Here you are essentially giving the program an answer it cannot directly calculate. Perform the analysis and you should have the result.

I did what you said and still get a error. Under the nozzle program,shell/head input values. Any suggestions?
I enter the following.
shell/head material name: SA-240 316L
type of shell: welded flat head
attachment factor:.3
large diameter for non-circ flat head: 17.75
angle: 90
offset:
shell diameter basis:17.75
actual thickness:.312
shell corrosion:0
I checked enter required thickness
req. shell thickness fot int. p.:.312
req shell thickness for ext. p.:.312
required shell thickness for hydro:0