Hi Everybody.

I just want to ask some advice on how to go through this problem of one of my equipment which was recently shipped at site. During transportation a long scratch was discovered on the shell. Upon measuring thickness on scratched area, I found out that this is below the thickness used in MAWP calculation, as stamped in the vessel. Is re-rating necessary?

As for the details, shell is made up of SA 516 Gr.60. Shell governed vessel MAWP, used thickness is 20 mm and required minimum thickness as per calculation is 17.88 mm. The new thickness on damaged part is 18.5 mm. Vessel is designed as per ASME Sect. VIII Div. 1.

As for the MAWP, vessel is stamped with MAWP base on 20 mm thickness. Now that the new minimum thickness of shell at damaged part is 18.5 mm, should vessel be again stamped with a lower MAWP?

Vessel will be put in service in Saudi Arabia. If vessel needs to be re-rated with new MAWP, what code shall be applicable for the re-rating?

Thank you..


Mojak

Absolutely no problem

DO one thing Refer Appendix 32 and provide your calculation to AI and follow his instruction.

I don't think need to go for R stamp.

yes re rating is desirable but provide him App 32 calculation for LTA.(Localized thinning Area)

hope it works,

Curious to know what will be outcome for this problem Please reply

thanks

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Niraj