When running the pipe stress analysis programme, the user will choose a specific support vendor and the analysis program will choose spring rates from that vendor’s catalogue. When using a different vendor, spring rates will be slightly different. This is usually considered acceptable provided the spring rates are reasonably close. If a different vendor is chosen, the analyst has the option of re-running the analysis specifying the selected vendor’s catalogue, but this is not usually considered necessary. Variable effort supports are manufactured using standard spring coils from stock and it is impractical to make one-off designs using non-standard spring rates.