Hihi,

Designing a fixed tubesheet heat exchanger where tubesheet extended as flange and welded to shell. Tubesheet material is SA765 GRII with impacted tested due to required MDMT is -10degC.

However, from PV Elite report found that tubesheet@shell side MDMT is 18degC by referring to curve B which is the same curve as shell material. Any reason? Should not be each component evaluated for impact test requirement based on its individual material classification?

Thanks you.