Where should we stop the model?

Hi, I am a new user to CAESARII. My pipeline is connectted to the existing pipe network by Tie-in point. The anchor support on the existing pipe is far away (more than 1 Km away). Should we model our pipe model to that anchor? If not, the new pipe will put force and moments on existing pipe. Thanks.

From the tie-in point, model both left and right until you cross three supports. This should be sufficient to model the effect of the header on the branch.

Be careful, as this (crossing three supports) is just a rule of thumb. Also, you are not modeling the interaction of the two systems. If your new brach line has any adverse effects on the header, you are missing it.