Determine MAWP of in Process Exchanger

[Headsup]

I am looking for a way to determine the MAWP of exchangers that have no design or nameplate information. The catch is that the exchanger will not be opened up for internal UT. These exchangers have been in process for a number of years. Can I rate this exchanger by performing calculation on external components (Shell and heads) that can be UTed and performing a pressure test UG-101M (stopping at 4 times operating pressure)?

If there is another way to determine MAWP in this case please let me know as I don't like the thought of testing at 4 times operating.

Thanks

 

[davefitz]

not sure, but the MAWP is supposed to be correlated to the design operating temperature ( minumim as well as Maximum), whereas the hydro test is typically at 70F.

If you do not know the materials of construction of all parts, and do not know the details of all welds, and have no knowledge of the welder's qualifications or fabrication NDT or a traceable material pedigree, I doubt that you can rate the MAWP based on an ASME code. The only possible way out is if it a "standard part" from the vendor, who in turn has rated such a part in the past .

 

[samuelliu]

Go ahead with API 510 PRESSURE VESSEL INSPECTION CODE: MAINTENANCE INSPECTION, RATING, REPAIR, AND ALTERATION.