crosby84
Mechanical
- Aug 9, 2016
- 24
I think this has been addressed previously, sort of, but I couldn't find my answer.
We evaluate pre-existing vessels (mechanical integrity, as they say) and frequently come across air receivers (ASME code stamped, NB#, etc.) that when we run thickness calculations, they are often at or below minimum required thickness. Even if the U-1 states a nominal shell thickness of 0.25", the min required thickness is 0.255" (exclusive of corrosion allowance), for example, and we have to tell the client that their vessel isn't good for the pressure on the nameplate, even if it hasn't corroded.
Why would manufacturers so frequently build these things right on the line with no CA, often even below the required thickness? Does anybody else run into this regularly?
Just curious to get others' experiences with this. Thanks!
We evaluate pre-existing vessels (mechanical integrity, as they say) and frequently come across air receivers (ASME code stamped, NB#, etc.) that when we run thickness calculations, they are often at or below minimum required thickness. Even if the U-1 states a nominal shell thickness of 0.25", the min required thickness is 0.255" (exclusive of corrosion allowance), for example, and we have to tell the client that their vessel isn't good for the pressure on the nameplate, even if it hasn't corroded.
Why would manufacturers so frequently build these things right on the line with no CA, often even below the required thickness? Does anybody else run into this regularly?
Just curious to get others' experiences with this. Thanks!