This is also our big problem in our current project, same situation with Techy06. It is for cooling water pump rated at 150lb. Finally my Senior Stress Engineer give up and decided to use tied expansion joint on each suction side instead we are restricted just because our materials for piping were already purchased. I talked to one equipment engineer here, he said there is a better idea. According to him, he would try to choose pump with higher rating with higher allowed loads instead of using expansion joint which the is much expensive.
I would try to convinced with my Lead Stress Engineer but I need also your opinion guys before him.

Regards,
Machoguy
"Do not postpone until tomorrow what you can do today"