ASME Code Replacement Parts

[uglyspec]

Hello,

When building a replacement heat exchanger bundle or a replacement part like a bonnet for an ASME Code Section VIII heat exchanger that was originally designed and fabricated to a previous edition of the ASME Code (ex. 1980 edition), is the manufacturer required to perform NEW ASME Code calculations, for all materials, to the current edition of the Code? Or are new calculations not required because you are replacing a part that has already been proven to work to an older edition of the code?

Thanks,

 

[metengr]

For pressure parts that are in-kind replacement, not altered, no code calculations are necessary. Only a P4 data report if fabricated.

 

[uglyspec]

That's what I thought but our Code inspector is telling us they are required and he pointed us to Mandatory Appendix 43. Does anyone else interpret this Appendix the same way?

 

[metengr]

Typically, parts would be furnished to the new ASME Code for contractual purposes, which is what Appendix 43 is about. The bottom line is the ASME stamp holder should provide a replacement pressure part with a P4 data report. It will be up to the supplier to determine if code calculations are required, and that is why I said for an in-kind existing part, all that needs to be done is to reverse engineer it, and provide a date report. This is done all of the time.

In fact, ASME is moving to having a pressure parts designator where there is no desgn responsibility, in other words, only reverse engineering parts with no design responsibility (calcs) under an ASME Certifiate

 

[uglyspec]

P4 data report is for Section I. I am assuming you mean U2 Partial for Section VIII parts?

Are you also saying on this U2 partial you would list the original code and edition (as applicable) that the part was designed to?

Looks like if you have a replacement heat exchanger bundle in which no welding was performed (roller expanded tube joints) NBIC allow you to stamp the new bundle with a "R" stamp.

 

[uglyspec]

Also, can you please be so kind as to point out where in Section VII it states no new code calculations are required for replacement parts? I will need this info with my conversation with our Code Inspector. Otherwise he is going to revert back to Appendix 43 which specifically states "Parts".

Thanks

 

[bpv66]

The Inspector is correct that the replacement "Part" needs to meet the current Code edition per Appendix 43.

But UG-120(c)(2) does not require design calculations for Parts. It requires the Part manufacturer to document the extent of any design calculations performed. As long as this is an in-kind replacement you only need to provide the U-2 and state "design performed by others" in the Remarks section. All other requirements of the current Code are to be followed such as material, welding, etc..

 

[metengr]

Yes, correct, U2 partial data report. My error.

Section VIII is a design and construction code with parts that are supplied for a new vessel, with no specific section on parts replacement. Whatever specific component is fabricated under Section VIII with pressure retaining welds will be stamped and supplied with a partial data report so that the R-Certificate Holder can install it, per the NBIC.

The repair work you mentioned is entirely under the NBIC, and stamped as such.

A pressure part supplied for the repair should be supplied by an ASME Certificate holder because that is what is required by the NBIC, Part 3. The use of calculations is up to the certificate Holder, if they can demonstrate the replacement part is of the same material, thickness, etc, there is no reason to have calculations, and pay for them.

 

[marty007]

bpv66 - I run into this question all the time also, but have taken a different perspective.

Let me play lawyer for a sec (I'm not a lawyer... I just like to pretend sometimes). You mentioned:

provide the U-2 and state "design performed by others" in the Remarks section

. If this is a replacement part in-kind, who is taking responsibility for the design? Often I see requests from mills for replacement parts, and I know for certain that they are not performing code calculations. In this case, if there was a failure, who would be questioned regarding the design? What if there is a fundamental design flaw? The original fabricator would certainly wash their hands of it since they had no role in the replacement part. Where does the finger point in the end?

 

[bpv66]

Marty007,

That's a good question. But, keep in mind the ASME Part manufacturer is typically fabricating the replacement part in accordance with a print/drawing from a repair organization or Owner of the vessel. In my experience it is not the Part manufacturer's responsibility to determine replacement head dimensions or material thickness of a replacement part. It is the repair organizations responsibility or, in some cases, the Owner/end user to provide that information in a purchase order and/or print. They would obtain the original Manufacturer's Data Report on the pressure retaining item or perform testing to determine dimensions of the "in-kind" replacement part. This would eliminate any liability on the Part manufacturer.

There are exceptions to this rule, thus UG-120(c)(2) requiring extent of design to be recorded on U-2 (think standard manway Parts).

That's my experience with Part manufacturer's from the Inspection side of the house. Maybe some of the engineer's on the manufacturer's side can provide some additional information.