We have seen seismic retrofit of many process plants not originally built for adequate seismic event.

But, in case we have to do the reverse, to relocate a plant designed for a high seismic zone to one with lower one (seismic codes are legislatively driven although), what could be the impact on hot large bore rack piping anchor/guide loads?

To qualify for high seismic event within occasional allowable stress, the piping needed to be sufficiently guided and stiff, thereby resulting in high thermal loads at guides and anchors.

Now, with lower seismic level, one can afford a flexible layout, larger gaps at guides/ less no of guides. We can still retain the original stiff design, saving piping stress effort while costing higher in civil design. Anything more ?

regards,

sam

If you are removing lots of guides, widening of guide, removing other restraints, you may end up having piping system which is too flexible and may run in very low frequency zone. Having such piping attached to any rotating equipment will have some adverse affects.
You may like to do few of above investigations before you conclude anything firm.

Good Luck