Working pressure upgrade
Working pressure upgrade
(OP)
Can the working pressure of an ASME code pressure vessel with U-stamp be upgraded (re-rated) from 75 psi to 100 psi? Perhaps by incorporating radiography? Has anyone ever encountered a request like this?
These vessels are currently operating at a water treatment plant in New Jersey and were installed in 1992.
These vessels are currently operating at a water treatment plant in New Jersey and were installed in 1992.
S. Bush
www.water-eg.com





RE: Working pressure upgrade
Also note that just because the nameplate says "MAWP 75 psi" doesn't necessarily mean that that's really the MAWP. More likely, that was just the design pressure, and the actual MAWP might be a bit higher. You'll have to run calculations to determine the actual MAWP.
RE: Working pressure upgrade
A re-rate of this type is considered an alteration and would be performed under the National Board Inspection Code, Part RC-3000 (2001 Edition, 2003 Addendum). The requirements for re-rating the vessel are very specific and are in the NBIC (review Part RC-3022, paragraphs a-d).
RE: Working pressure upgrade
Any PV designer with an appropriate drawing could get this part sorted.
The rest depends on your regulatory environment.
Cheers