Our Client does not want us to use Annex-F, and therefore design with 1 time API610 allowable for pump nozzles. We tried to explain to them that this does not only require a lot of time to analyse and qualify the nozzle loads but also results in a overly flexible piping system, prone to vibration... but the Rotating Equipment specialists think they are going to save on maintenance and downtime of the Pumps by doing this.



I strongly feel that application of Annex F should not be a problem as the loads are still quite low and are guaranteed by the manufacturer. I also belive that having too many springs, bends, teflon slide plates gives a theoretical solution but the reality could be opposite.





Does anyone have any reference article or similar on this subject that will reinforce my views (or otherwise)? Thanks for your attention.

Shorustress,

API 610 does allow to use pump nozzle loads more than that of Table 4 considering that we satisfy annex F, but, by doing this method can result up to 50% greater possibility of misalignment to occur compared to using table 4.

You can't really argue with your client if they want to neglect using annex F of the API 610, it is there call and our job to satisfy there requirements. Annex F is non-mandatory but an option as a method to allow use of loads more than that in table 4 values for API610 pumps.

Goodluck!