Trim Selection 1

[Jmoore1]

Hi All, I am trying to determine choice of trim for a valve...products are clean (mostly dry pentanes), valve is currently trim 8, I am being asked for trim 5, and the pipe spec calls for trim 12, what is the basis of a trim selection? is it mostly for material degradation??

 

[DLite30]

Yes, trim selection is mainly made based degradation due to corrossion by the process fluid. However erosive materials in a fluid may factor into the decision for valve face/seat hardness.

 

[reverman]

Material compatibility is the biggest factor in general but frequency of operation can also factor into trim selection. If you have a valve that will be operated very frequently it is advisable to go with a full stellite trim like trim 5 or trim 16. with both surfaces hardfaced the valve will see less wear.

Not sure if this is the case in your situation but when I see a valve spec that calls for Trim 12 and the customer asks for trim 5 what they actually want often times is trim 16 which is 316 sst with full stellite. Many customers don't understand/forget the stem is defined in the trim number. They just use trim 5 to mean full stellite seats forgetting it also means a 13%Cr Stem