coating integrity at lap joint of roof

[nickelkid]

Not being well experienced with Tanks, I am reaching out to find experiences with coating integrity of tank interiors at lap joints. It is an API-650 Tank, carbon steel contruction. We have received conflicting recommendations...

Thanks in advance.

 

[adammal44]

What are your conditions? Outside/indoor tank - general region - desired operating life?

What recommendations have you received, with what background?

 

[nickelkid]

Nominally ambient conditions, hydrocarbon, outdoors in a tank farm environment. As noted we have conflicting recommendations, but would like some input from one experience with coating inside of API-650 tanks.

Possible contractor is expressing reservations, coating supplier has advised to coat for application. Not sure if this is just a contractor that does not want to take the time to prepare surfaces correctly or if this is an area indicative of having problems with coating adhesion.

 

[nickelkid]

Due to field erectors concerns with coating integrity we have decided to coat inside wall and floor only. Stored fluid is easily contaminated so we do not want contact with weld seams. Tank is purged so we believe it will be okay to not have subject joint coated as it is in vapor space.