Help (Hydrostatic Loads) 1

[Mrbobbyjoe]

Hello all!
I have an odd question, but hopefully I can get some help. working on a project that requires spring can data. After running a hydrostatic analysis, it is showing to be less weight than the installed loads. This does not seem theoretically possible but maybe so? Just to give brief information, the vessel would be pushing the pipe down into the spring hanger and the pipe then bending in a horizontal direction. If anyone can inlighten me on the way caesar works with this, that would be most helpful.
Thanks!

 

[richay]

My first suggestion would be to recheck all of your density input values.

If you still have issues, post on the COADE Discussion Forum, or send and e-mail with your model to "techsupport at coade dot com".

Richard Ay
COADE, Inc.

 

[NozzleTwister]

I'm giving you a star Mrbobbyjoe for actually looking at your analysis results and trying to make sense from them. You'd be surprised how many don't.

CAESAR II has an excellent hanger sizing module with a lot of user controlled options that allows you to have CAESAR size your spring exactly the way you want it. Refer to CAESAR's on-line help manuals for those features.

Like Richard said, review the densities of your operating fluid to make sure they are correct. Also, I assumed you used 'WW' (water filled weight) for your hydrotest run.

You didn't mention how much difference in weight, but it's possible for the hydrotest weight to be less and happens often for liquid filled lines for several reasons.

You said your pipe is moving down at the spring location in the operating case. Your operating load will be the cold load + 'travel x the spring constant.' There is no travel in hydro and CAESAR locks the springs for hydro runs making them hard supports. Also you may have had lift-off or load reductions at adjacent supports during operation and requiring the spring support location carry extra load. You may have also freed an anchor for spring sizing causing the spring to pick up extra weight.

Good luck,


NozzleTwister
Houston, Texas