Song,

To attach images directly, look for the "Switch to Full Reply Screen" button below. Simply attach the image files and they will render at the end of your message. I am incapable of seeing the image you linked to, however in MY image, you can see "DEFLECTION." This value includes thermal and hydraulic deflection. However, if you instruct CAESAR to have a "temperature change" of 0, then all you will have left is hydraulic.

Generally in pipe stress modeling when attaching to equipment, you have three options:

1 The equipment is rigid and the pipe is flexible - equipment moves the pipe.
2 The pipe is rigid and the equipment is flexible - pipe moves the equipment.
3 Both pipe and equipment are of similar rigidity/flexibility.

You should strive for option 1 whenever possible, as it does not require the analysis of nozzle stiffness. Reported stresses and nozzle reactions should be conservative.

My opinion is you only need the nozzle stiffness values if you expect the pipe to offer significant resistance or impart significant load into the tank. I would prefer to limit this kind of analysis to existing tanks and existing pipe with poor flexibility characteristics.

Dave,

We ran into a couple challenges on some of our tank models, and the easiest way to be consistent across the board was to manually specify displacements. The short list of complications includes:

• Modeling nozzle displacements in combination with tank settlements. We could not pinpoint why stresses seemed to have been coming out correctly, but reported displacements seemed to be an average between the two.
• Using the Nozzle Flexibility input option and manually specifying the displacements sometimes interfered with each other, so we would ask CAESAR to calculate these values, and then turn the Nozzle Flex off on subsequent runs.
• Nozzle Flexibility will not work if your tank nozzle projects into the tank, although we did not attempt to connect this via CNODE. However, I opted this out of the analysis due to being existing and operating on the assumption that the tank moves the pipe - if there's a problem already, we didn't create it, and we weren't asked to look at existing problems unless they caused failure in items within scope.