haljordon,
Your sentence is extremly difficult to understand, but let me try to see if I understand your question.
I think you are trying to say you have a fabricator who does not have a U-Stamp for their shop. As such, can he build a code pressure vessel?
If this is what you mean, then the answer is NO. However, if you choose to not register and U-stamp a "pressure vessel" then, of course, that's your risk. If you do that, no insurance company will take on the risk for your plant.