For piping systems that contain no expansion joints, the axial loads include a longitudinal force calculated as Pressure X Internal Pipe Area.
Reporting this force to the pipe cross-sectional area, you obtain the stress due to pressure load, usually counted as "PD/4t".

In "EJ with no rods" case or in case the rods are not working, the EJ "breaks" the piping system in two parts and the pressure thrust is acting on both of them.

I suggest you to see also
http://65.57.255.42/ubbthreads/ubbthread...=true#Post33752

You can find there a sketch for Peng's book.
In fact, there is an warning that the existence of roads is not always a guarantee. As you can see, Mr. Peng made a suggestion on the piping part.

Best regads.