Equipment Model

Dear all;
I would like to know your experience about equipment model in caesarII.

I try to model equipment from support of equipment to nozzle of it, I want to know how to specify support of equipment (Tank or Heat Exchanger)
1. anchor.
2. Y,Guide and Limit.
3. +Y, Guide and Limit.

Which are reasonable. Please explain me.


The other question; Can I use WRC297 to analyse the Nozzle flexibility of Heat exchanger's Nozzle.

I'm just a beginner......

Thanks

I typially model a full anchor at the fixed saddle support and a Y and guide at the slotted/sliding saddle.

Your goal is to model the movements that your equipment connections are going to impart upon the piping system.

Hi all
I got some question from my client that;
I model vertical tank, 30000 mm high, as following
1. Model a skirt as anchor (Node 10)
2. Model vetical tank, 30000 mm high, as a rigid high 27000 mm (node 20), then
3. Model rigid from center line of tank to tank's surface lenght is radius of tank (Node 30), then
4. Model nozzle as normal pipe (Node 40).

They found displacement in downward direction at the nozzle (node 30), the displacement is -30 mm. in case of sustained case.

I try to change rigid to normal pipe (Dia = 4000 mm, thick 18 mm), the result is the same.

I think that imposible. why they move down during installation. or I'm wrong model.....
What is correct??

Regards.

Something isn't right, from what you describe there I find it hard to believe the nozzle moved down.

One caution, you don't want to declare the vessel as a rigid element. Use regular pipe elements for the vessel, which will allow horizontal deflection in the event you apply wind loads.

Are rigid elements not allowed to deflect laterally?

I thought the diameter of the rigid element input and 10 times the thickness is used to determine the stiffness, but still it is allowed to deflect based on that stiffness.

Please clarify.

You're right, ID+(10*thickness) is used to determine the stiffness of rigid elements. But, if you have a tower, that has a wall thickness of 0.25inches, and you call it rigid, its deflection will be based on a psuedo-thickness of 2.5inches. You don't want to do this, because the real tower will deflect a whole lot more than your model.

Rigid elements should be used for valves, flanges, equipment (such as pumps), and dummy construction elements. I highly suggest you don't define vessels as rigid.

Are the results showing displacement at your anchor point node 10 also ? If yes, then please check if you have given a connecting node at the anchor node. ( Anchor node 10, CNODE some node no.). If you give a connecting node and don't give any displacements, then it will show displacements. Remove the CNODE and re-run the model.
John

Dear all;
Thank you for your opinion.

John. I checked node 10. It was anchor, not CNODE, so it didn't have any movement. And node 20 is no movement also.
I think nozzle move down because of rigid from Node 20 to Node 30 is flexible because weight of nozzle and pipe. Right?

Pornlert W.

Mr Pornlert, do you happen to have the rigid from cl of tank to inner wall with an OD equal to nozzle diameter? If yes, then, that is the problem, Rigid OD should be equal to Equipment OD in order to have enough stiffness and have the same movement between equipment CL and inner wall of equipment.

Good Luck