ASME U Stamp and unlisted material 1

[soletto]

Hallo guys,

i need to perform a calculation report for ASME U Stamp Audit.

The Pressure vessel should be 650 bar / 260°C and ASME Division 2

The material is SA723 Gr3 Cl3

Now my problem is that i cant find allowable stress values for that special material.

Im looking in the ASME II PART D - METRIC (2019) Table 5A

Now my question is: Can i use this material for U Stamp?

Do i need to calculate the allowable stress value according Mandatory Appendix 10 Table 10-100?

Thank you,
BR Stefan

 

[DriveMeNuts]

I think ASME VIII Div 2 Annex 3-A.1.1 will give you your answer. It's not listed, and therefore not allowed.

This material spec is mentioned Div 3. 650 bar is Div 3 territory.
Typical UTS and yield are in the material spec. These numbers plug straight into the Div 3 calcs.
As the properties are not mentioned in Table U and this is a forging, perhaps Div 3 requires actual material properties stated on the material certificate?
Including forging specific tests conducted at elevated temperatures?
It would be interesting to learn more.

 

[Geoff13]

Is this a permitted material listed in Div 2 Annex 3-A? If it's not a permitted material then allowables won't be printed in Part D.

 

[soletto]

I found SA723 G3 Cl3 in ASME II PART D - METRIC (2019) Table 2A as ASME VIII Division 2 Class 1 Material

Im a little bit confused

The pressure vessel is 650 bar and it should be a division 2 calculation indeed

However SA723 G3 Cl3 is listed in Table U.

Now i took the values from Table 2A

for 260°C i used 356 MPa (1070UTS/3)

I use ASME VIII Division 2 Class 1 (SA723G3Cl3 is listed in Table 2A)

 

[DriveMeNuts]

I searched again and found it.

In table 2A Grades 1, 2 and 3 are allowed. Grades represent chemical composition.
Only Class 1 and 2 are mentioned in Table 2A for VIII-2. Class 3, 4 and 5 have "NP" in the VIII-2 column (Not Permitted).

Div 2 Annex 3-A Lists Class 1, Grades 1, 2 & 3 and Class 2, Grades 1, 2 & 3.
Class 3 is not listed and therefore is not allowed.

Class represents mechanical properties and Class 3 has lower elongation and impact strength than Class 1 and 2. This is the likely reason for its exclusion.

Class 4 and 5 are also excluded.

 

[soletto]

It is clear to me now.
Great Post and thank you for the help!

 

[tigny]

Hi,

As stated by @drivemenuts, the first thing to do would maybe to go to chapter 3-A.3 TABLES in the ASME.BPVC.VIII.2 in order to know which materials are allowed.

Then only after that you would go to ASME.BPVC.II.D.

Same applies for Division 1; first look at the -23 tables in the Subsection C (TABLE UCS-23, TABLE UNF-23.1 etc. ) then for the allowed materials go to II.D

best regards