SA-182 VS SA-965 for heat exchanger tubesheets and girth flanges 1

[FPPE]

I reconnect to this thread.

Is it correct to order a tubesheet or a girth flange for a heat exchanger in accordance with SA-182 instead of SA-965 for SS316?

Reading the specifications, it seems that both are applicable, with the difference that SA-182 is limited to products weighing less than 4540 kg, beyond which SA-965 is required.

The doubt about the validity of SA-182 for these applications arises from the first lines of the specification, where it states:
"This specification covers forged low alloy and stainless steel piping components for use in pressure systems. Included are flanges, fittings, valves, and similar parts to specified dimensions or to dimensional standards, such as the ASME specifications that are referenced in Section 2."

Since SA-965 is also referenced in Section 2, it would appear that SA-182 is applicable for the same purposes, including tubesheets and girth flanges.

Thanks in advance for your answers.

 

[SnTMan]

SA-182 is used all the time...

 

[Krausen]

Yes SA-182 is very common for SS316 girth flanges & tubesheets (forgings) for HXs

 

[FPPE]

SnTMan, Krausen,

I agree with you; I have never seen a heat exchanger drawing with SA-965. I just wanted to understand if there was any specific detail in the code that would make it incorrect to use one material instead of another.

The same applies to SA-350 and its equivalent for custom-sized forgings, SA-765, or to SA-105 and its corresponding custom-sized equivalent, SA-266.

In that case, it wouldn't be correct to manufacture tubesheets and girth flanges in SA-105/SA-350, right?
Since these are custom-sized components, they should be specified with SA-266/SA-765.
The same principle applies, for example, to Cr-Mo materials, where SA-182 is used for standard components (e.g., flange nozzles), while SA-336 is used for tubesheets and girth flanges.

Whereas, for austenitic steels, it seems that there is no need to differentiate the material between standard-sized and custom-sized forgings (the specification is SA-182 for both, except for weights exceeding 4540 kg).

 

[Christine74]

See UG-6(c).


-Christine

 

[Krausen]

In that case, it wouldn't be correct to manufacture tubesheets and girth flanges in SA-105/SA-350, right?
Since these are custom-sized components, they should be specified with SA-266/SA-765.

No, you can design custom girth flanges & tubesheets to SA-105/SA-350 all day long, so long as you fall under the requirements of the specs. Most carbon steel girth flanges & tubesheets are SA-105/SA-350. I work up North, with low MDMT requirements, so all of our CS girth flanges & tubesheets are designed to SA-350 to achieve the lower MDMT rating under Section VIII

 

[SnTMan]

I seem to recall SA-105 was not permitted for tubesheets. Is that correct? Been changed?

Regards

 

[Krausen]

I seem to recall SA-105 was not permitted for tubesheets. Is that correct? Been changed?

This may be true now, I'm not 100% sure. I never deal with SA-105 on tubesheets or girth flanges on new HXs since we're always going with SA-350 to get out of any impact test requirements for our lower required MDMT ratings. I know we have many older HXs that are still in operation with SA-105 tubesheets & girth flanges though.

 

[SnTMan]

From 2007 Ed A08 Sec II, Part A, SA-105, Scope: "Tubesheets and hollow cylindrical forgings for pressure vessel shells are not included within the scope of this specification."

No idea if it has been changed since.

 

[IdanPV]

It's still there, in the scope of the spec.

 

[Christine74]

Forged SA-105 tubesheets are permitted in ASME Section VIII Div. 1 provided that all of the requirements of UG-6(c) are met.

"Forgings certified to SA-105, SA-181, SA-182, SA-350, SA-403, and SA-420 may be used as tubesheets and hollow cylindrical forgings for pressure vessel shells that otherwise meet all the rules of this Division, provided that the following additional requirements are met:"


-Christine

 

[GD2]

It will be incomplete to comment without the process in play. The process will typically decide on the material selection like Krausen said.
Once the material is selected, you see whether it can be resourced easily and local fabrication expertise is available. If not, you go the next material in the selection list.
Both technical and commercial evaluations need to be done.

 

[SnTMan]

Christine74, yes, I had forgetten. Part of 2017 Ed, don't know when it was added. Thx

 

[FPPE]

Dear all,

Thank you very much for the clarification, it seems that in Europe there is a bit of confusion on this.

Best Regards

 

[r6155]

SA-965 for shell flange and tubesheets.
SA-182 for nozzle flange and fittings.