First you should review the system to find out as to why seismic cases are governing the spring design, too many springs? excessive flexibility? poorly supported heavy masses? etc. and if possible reroute/ add rigid supports near the heavy masses to stabilize the system for the dynamic loads. As pointed out by mariog, you may consider use of seismic snubbers at appropriate locations.

Now about the query, generally selection of spring support is done considering operating condition, but one should always ensure that selected spring can accommodate extreme movements/ travel and that spring support does not bottom/ top out. So, IMHO you should consider the displacements in seismic case while deciding travel for constant spring supports. There are different configurations for the spring support and attachment types with pipe and structure to chose from. Have look at Type VBM from Bergen Pipe supports catalogue for reference.