Allowable stress for 31254 tube in ASME Exchanger

[bmoorthy]

Where can i find the allowable stress for 31254 tubes?

I could not find the 31254 seamless tube specification in the first place in section II A or In Section II D.

Can i use allowable stress given for Plate or Forging, when for a specified product form the allowable stress is not found in the ASME Section II D?

I remember seeing an interpretation some time back on this allowable stress (In the context of Duplex grades)can some one provide me the clause in ASME that permits us to use allowable stress of plate to be used as allowable stress for tube or the relevant interpratation?

Thanks in advance

 

[metengr]

Can i use allowable stress given for Plate or Forging, when for a specified product form the allowable stress is not found in the ASME Section II D?

No. UNS 31254 tubing is not listed as an endorsed material specification for tubes (I did not check if there was a code case for UNS 31254 tubes or pipe). If there is no code case, you would need to generate one for using UNS 31254 tubes.

 

[gr2vessels]

bmoorty,
Since there is no S31254 material endorsed by ASME (despite of UNS number!) that means there is no fabricator producing this tube. You must have got the equivalent UNS number from an European or Japan or other fabricator, who produces the tube under a different name. You should use that material specification and the relevant European code listing the tube (and the relevant allowable stress), eg. YUS 270 from Japan, Avesta 254 SMO in Europe, etc. Please note that most (if not all) the PV softwares have included already the design stresses for the 6Mo materials, including the S31254.
Also, doesn't seem ASME obsolete?
Cheers,
gr2vessels