ASME BPVC, SB-564 N06625, no Grade 2 option in IID

[timsch]

Apologies in advance for the double post (slightly reworded). This question was originally posted in the ASME (MECHANICAL) CODE ISSUES section, but didn't get much traction. ----------------------------


Our company has been asked to provide a temperature measurement assembly in Inconel 625, Grade 2. I find this grade for ASME SB-444 & -446, but not for SB-564 in ASME BPVC SEC. IID. I had informed the project managers that we would not be able to meet this requirement, and that additional solution annealing at the temperatures required for Grade 2 in -444/446 would not be allowable.

They then provided me with an MTR from 2013 for a 600# RFWN flange that had the following specifications:

ASTM B564-11, B446-03 N06625 GRADE-2 (SOLUTION ANNEALED)
FORGED PER B564 PRACTICE H.T. (GRADE 2) & MECH. PER B446.
DIM/TOL PER ASME B16.5-2009

I've always run calculations per the ASME BPVC SEC. VIII, DIV.1 code, so don't know if there are other codes that will allow use of ASTM standards that may accept a flange with this combination of specifications. I assume that this would not be allowed in an ASME U-stamped vessel. If this combining of specs for a flange is acceptable, please let me know how. Thanks.

 

[EdStainless]

Don't' look in the tables but look in the spec, does SB564 allow the Gr2 HT temperature?
If so then there's a way to use it.
In ASTM and ASME either you meet a spec or you don't. The only time that you say that part of it is to another spec is when the fist spec is silent on that issue.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[timsch]

SB564 does not allow the Gr2 HT temperature. N06625 is listed only in the annealed condition, which would be Gr1 in SB-446. YS & TS as shown in the attached MTR are below the minimums for both the current and the older version of SB-564 that would have been valid in 2013.

It seems to me that this could not be used for an ASME BPVC CODE-U job, but the previous engineer allowed it and it was accepted by PED, so I want to make sure I'm not missing some loophole.