Nozzle loading on flat plate

[IFRs]

I have a rectangular oily water storage vessel 36" high with a 64" x 52" footprint. The bottom has (2) 16" nozzles to be installed sticking out (down) from the bottom. The owner has told me that there is 3,600 pounds of axial load and 12,400 foot-pounds of moment on the nozzle flange. I'm looking for a quick and dirty way to determine the required thickness of the bottom and/or reinforcing plates. The amount of material is small, so the cost will be small but I need a technically defensible method to get the thickness. The mounting and support of the vessel is done by others. Any help will be greatly appreciated!

 

[JStephen]

Make a reasonable assumption about distribution of the reactions around the outside of the bottom plate, and you can then cut sections at different locations and find average bending stress at those sections.

A common problem in nozzle load calculations is that the nozzle loads may have been calculated assuming a "rigid" connection to the tank, and can then be off ten-fold when the flexibility of the connection is figured.