I am carrying out the stress analysis on a new heater transfer line.

Existing 42" lines from 14 heaters are incorporated to 78" header line and
one new line (36") from new heater is to be incorporated to the existing header.
MOV(Motor Operating Valve)s are installed in each transfer line for decoking and
the new line also.
Through the stress analysis result, I know that there is no problem in the new line
including its interaction with the existing lines.
However, the problem arises from the project schedule.
Before the new heater arrives at the construction site, the 14 heaters are
to be shut down and the new line is to be constructed in part, from MOV to the exsiting header.
After that construction, the 14 exsiting heaters are to be heated up again.
The rest of the new line, after MOV to the new heater, is to be contructed a couple of months later.
After all, it makes about 60mm lateral offset (misalignment) between two parts of the new line because the
previously constructed part of the new line is to be somewhat heated up.

My question is

What is the best way to simulate this situation without lateral cold springing expansion joint?
(I don't think that it is a reasonable way to designate displacement at the break point.)

Thank you. ^_^

This sounds a lot like "hot tapping". There is an article on this subject in our October 1996 issue of <font color="0000ff">Mechanical Engineering News</font>. If you don't have a hard copy, you can get it from this web site by clicking here .

This is not a trivial analysis. I suggest you simulate the behavior and the analysis with a very small model, so you can understand the procedure and the results. Then you can work with your real model.