SA-387 9 Chrome Plate

[Afox88]

Hi Guys,

I am designing a unit to ASME Section VIII-1 that is 9 Cr-Mo. I found all the other forms in Section II-D but the stress values are not there for plate. I checked in Section II-A under SA-387 and I did find grade 9 so it is an approved material.

Any thoughts or ideas how I am to perform calculations on this material form?

Please advise,

 

[SnTMan]

SA-387-91, 9 Cr-1 MO-V? Pg 46, lines 25, 26.

A material must be listed and permitted in Sec II, Part D for a given Sec & Div to be used under the same. Presence in a material spec is not relevant.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[Afox88]

So my understanding is that SA-387 Grade 9, which is readily used in refineries for pressure vessel materials in high temp application, is wrongfully used?

Grade 91 is a different material with a different P-no. It is not really interchangeable.

I have contacted my inspection agency for their thoughts.

 

[metengr]

SA 387 Gr 9 plate material is not listed for allowable stress values. You cannot use this material specification Grade for pressure retaining service UNLESS a code case has been issued.

 

[HBMetals]

metengr is right. ASME SA387 Gr.9 plate is not within the jurisdiction of ASME BPVC Section VIII Division 1. It can't be used. I also did a thorough search on Code Cases - 2015 Edition. So far nothing regarding 9Cr-1Mo is found. However, I have a question: when a new edition of code Cases is released with the BPVC, shall all old editions be treated as "obsolete" automatically?

 

[metengr]

Not sure what you mean as obsolete. ASME Code Cases are published based on need and when new revisions are issued for a Code Case they can be used for new construction at the time they are issued. Previous code case revisions do not apply.

 

[weldstan]

SA-387 Grade 9 had previously been in the Code then it was removed and again readmitted. Now they have removed it again. I suggest you contact the appropriate Code Committee for guidance,

 

[Afox88]

I was advised by my AI that under the rules of UG-15(a), we are allowed to qualify SA-387 9Cr based on the values of a different product form of 9Cr (ex. SA-213 T9 tubing). Therefore, we would be able to use SA-387 9Cr for this exchanger.

My customer has allowed me to use Grade 91 Chrome for all materials so this point is moot, but I thought I would follow up with you guys.