Tube Sheet Material

Regarding tubesheets in shell and tube HXs, SA 517 Gr 70 is probably the most commonly used material.

By "U Stamp job" I assume you mean an ASME Code Stamped heat exchanger.

Somehow, in the third world, it is assumed that Codes and Standards are full of restrictions and not permissions.

For example, these fora are chock full of absurd messages with postings such as "Show me where it says in the Code that I cannot make a tubesheet out of bamboo ?"

Codes and Standards (mostly) do not tell you how you CANNOT do something......They provide instruction and rules for how you CAN do something