Just wanted to make sure I was performing this MDMT assessment correctly. I have an exchanger shell that is made of ASTM A212 Gr. B made in 1963 (cannot verify fine grain practice). The shell and head are nominally 0.625" thick (0.5+.125 CA). I have a bolted tubesheet that is 3+5/8" thick. Using API 579 and ASME UCS 66 I get a governing thickness of about 0.90625 (vs 0.625) due to the tubesheet (1/4 thickness). Therefore the MDMT at full pressure should be (curve A for both materials) 64 F?
The reason why I ask is because someone before me assessed it at 40 F (which is close to 44 F if 0.625 is the governing thickness. Who is right?
The reason why I ask is because someone before me assessed it at 40 F (which is close to 44 F if 0.625 is the governing thickness. Who is right?
