Hi all
I have gone thru some of the topics regarding the modelling of rubber bellows. One thing that i am still confused is that if we select a specific length element to be modelled as rubber bellow, then we need to put all the stiffness values and effective ID in the expansion joint spread sheet. so what about the material . suppose im am modelling piping system of API 5L GrB. Do i need to change the material for rubber bellows to " Custom Material" and input all the values also? If so, How to calculate H1, H2, H3 ... and allowable stresses?

Please help . I would really love to learn more.

thanks

Your expansion joint data will be used in place of the standard pipe data in determining the stiffness, load and response of this element. CAESAR II will not calculate stress on an expansion joint so don't worry about that either.

Its new for me that stress calculation for rubber material.
The manufactor for rubber bellow give max displacement.
Check this with your results.

So that means, i need to input only the values for the stiffnesses and effective ID ( from the manufacturer) in the expansion joint spread sheet and nothing to change in the materials (input) for that particular element for bellows.

Please correct me if iam wrong.

Thanks in advance

Exactly.

Hello Gentlemen,

I am also new in doing an analysis using expansion bellows and I have a couple of unclear issues.

Do we need to evaluate the expansion bellows just like in existing spring hangers, if we do then what should we be looking out for? or do we just simply input the properties of expansion bellows in CAESAR II and evaluate its effects on piping?


Hoping for your soonest reply.


Thank you very much.

You should stay within the movement capability as specified by manufacturer.

Best regards,