Foundation loads

[Flash8111]

I have a 48" dia. vessel on 5" x 5" x 1/2" angle support legs.
The vessel has 2 large 14" and 16" dia, nozzles. The client wants
allowable nozzle loads and foundation loads from the allowable
nozzle loading. This seems like an indeterminate structure to me.
Does anyone have any suggestions on how to resolve these nozzle loads
and determine the foundation loads?
Thanks in advance.

 

[SnTMan]

If your nozzle loads are to be treated as dead loads, you just resolve the system of forces & moments to the world. But...

They hardly ever are just dead loads. Good luck.

Regard,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[JStephen]

Assuming there are four legs-
Establish your main axes as centerlines between those legs.
Resolve nozzle loads into components along those centerlines.
So you'll wind up with X and Y axis, with force in X direction and Y direction, and overturning moment about the base in X direction and Y direction. And if applicable, torsion about the vertical axis.
If you have the total loads and moments, you don't necessarily need to break it all out per leg, either.

 

[Trestala]

Nozzle loads can be broken down to thermal, dead loads, and occasional loads. Its full value would not be transferred to the foundation on a sustained basis, so what you are doing might be overly conservative.

 

[JStephen]

One thing to beware of- sometimes, the piping people will generate loads assuming the tank/vessel nozzle is fixed in space. With a small vessel on legs like that, there will be some flexibility, and if they don't consider that flexibility, the generated nozzle loads may be ten times too large.

 

[r6155]

See Pressure Vessel Design Handbook, D. Moss

Regards
r6155