Recently, we faced one funny issue of uncalled-for respect to Caesar-II in Centrifugal compressor nozzle alignment issue from piping construction community!

Construction want to achieve centrifugal piping nozzle alignment prepared with the springs in locked condition at cold position; till then, they will not call stress audit to verify flange alignment. They may have to cut pipe at closure spools to achieve alignment.

Then, they will insulate piping, remove temporary supports and call stress audit people to chk flange alignment with springs unlocked at compressor nozzle flanges as per API-686 max 1/16 in offset at bolts & 0.001 in per inch parallel limit. If this reqt is not met, stress to suggest what to do!

WYSIWYG - as alignment chk will be done with springs unlocked and as sustained Caesar-II run is not with as-built spool and valve weight with supports and insulation, is it not right way to align the piping at first with springs unlocked by construction and use spring turnvbucle to microtune springs to avoid pipe cut for flange alignment and redo sust run with revised cold loads ?

What our forum people think - is cutting pipes twice- once with spr locked and then unlocked a wise idea!
reg,
sam