Hi friends,

Normally X,Y and Z restraints without gap should be given at the terminal point in ceasar. so is there any options instead of x,y,z restraint at terminal point?....

You should have a few options, but it really depends on the situation.

Exhaust piping might not have any restraints at the end.

Tying into a pressure vessel or tank may have you terminating a line with an anchor, an anchor with displacents, an anchor cnoded to a different part of the Caesar II model, which is a Caesar II piping model version of the vessel.

Buried pipe will be a series of supports with friction and resistance.

Sometimes an anchor will do.

Sometimes it's similar to the exhaust case, but with a point force applied.

It's really up to the stress engineer to determine what's best, however.

A terminal point should be modelled in a Caesar II calc as close to reality as possible. That would normally be as you noted (although you have not restrained rotations), or as an anchor, or a set of displacements and three rotations. You might want to specify a gap or a spring rate in addition.

Do not mix displacements and restraints at the same node.

@Michael fletcher & Moverz.

Thankx for your instant reply.

I do stress analyis(static) for TEG system. Normally i was suggested to provide "x,y,z restraint without gap" at terminal point. so far i have done like that without problem. but now i do the last part of the system, in which the line has terminal point which is connected to LP flare. so, i provided x,y,z restraint at this point. but the system fails. if without x,y,z restraint, the system passes. can i leave that terminal point without restraints or any other options?...

Are you saying that your terminal point offers no rotational restraint at all ? If there is fixity you must consider it, otherwise your results will be rubbish. (GI/GO).

If your system fails when you restrained it correctly, the pipe is not flexible enough and probably needs a re-route / loop, or modification to other restraints.

As your system is connected to Flare system, you should be careful with the influence of this line. Normally at battery limit you have an anchor point. You can not end your system without having anything (like is disconnected). You should combine your engineering effort with the ones that have the interconnecting in their scope of work.

Normally you will have to include in your analysis also a part of flare line.

Regards,

What are your contructual obligations for the terminal points?

Does your company have the contracts on both sides of the terminal points?

In case there is no specific restriction due to operations, maintenance etc..., and you are obliged to do the analyses of both sides of the terminal points you can take stresses under allowables by using/not using supports at the terminal points.

But you need to answer first two questions above.

Regards,

Ibrahim Demir