Using Fig. UCS-66 for SA-333 Gr. 3 3

[MalcolmA]

I am trying to use Fig UCS-66 for a nozzle neck constructed of SA-333 Gr.3 material. The shell of the vessel is constructed of SA-203 Gr. E material.

In the notes section, SA-333 material is not assigned to any curve. I assume that it would have the same requirements as the SA-203 Gr. E since they are both 3.5% Ni material.

Am I missing something? How do I apply Fig. UCS-66 for SA-333?

 

[doct9960]

Curve B applies to SA-333. Read Note (2)(c) in Fig. UCS-66.

 

[MalcolmA]

Thanks for the reply doct9960. I agree with you that it goes on curve B.

The reason that I asked my question is that it does not make sense to me that this material should be on curve B. I just wanted to see if I was missing something. It is equivalent to SA-203 material except that it is pipe instead of plate. Also, the B31.3 piping code exempts it from impact ot -155F.

This nozzle is on a vessel that has an MDMT of -106F. I am working on a procedure to replace a corroded nozzle, and I will just have to purchase impact tested material.

 

[jamesl]

SA 333 Gr 3 is impact tested (at -150 F) material. It is exempted from impact test for Div 1 construction. It is not covered by Fig UCS-66. It is covered by Para. UCS-66(g).

 

[doct9960]

james has hit the nail on the head with para. UCS-66(g).