I am working with the client regarding storage tank (API 650 code)- build 1960 - 304 SS Material - ID =14' , H = 20'

Per fabrication drawing, the shell thickness was = 3/16" = 0.1875" so per specification I build the tank model in TANK software. No problem.

last month, they did the inspection at couple of places and the Ave. wall thickness is = 0.201"

My question - How come the value get higher. I thought because of the Corrosion (If any for 304 SS),it will be lower?

Please let me know your expertise.

Can I enter this valve = 0.201" as nominal thickness in TANK software.

I appreciate your help.

Regards,
Mayur