Case I:
Erosion in Pipeline Branch of line Medium pressure (MP) steam is separated to Steam trap occurs near Elbow ( the Elbow) at the point of impact of the Flow by Steam flow in Line that runs Steam trap that resembles a Two-phase.
Case II:
Erosion at the opposite tee fitting of the Low-pressure (LP) steam condensate pipe is caused by the two-phase flow (Flash steam + Liquid condensate) from the pipes that condensate from the steam trap that is combined.
Case III:
When Liquid Condensate runs through the Control valve, some are turning to Flash steam becomes Two-phase flow and flow turbulence ( Turbulent) resulted from Erosion , especially at the point of impact on the joints of the various (Elbow, Tee).
AMARINE 
Dear Sir,
I read in your web site Erosion in Refinery, Petrochemical Plant in different causes.
Regarding to Case II: do you have any more detail information analysis for that cause.
Have nice day,
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It’s about the cavitation effect.
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How to avoid the erosion after the control valve
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