Inspection Intervals - Multiple Storage Tanks

[tuan]

How would you prioritize inspection intervals across hundreds of tanks in a petrochemical complex?

[ben]

tuan,
There has been a risk based inspection scheme which is applied starting from consequence ranking, moving to ranking the probability of failure and performing a risk evaluation with the product of these two, keeping that semi-quantitive or quantitative. Once this risk assessment is done, urgency of inspection comes out.
Then damage mechanisms based grouping is done which helps keeping all many hundreds on tanks in check.

[mechcolor]

It is a dynamic analysis which keeps on going supported with inspection results from each inspection performed, external or internal.
Just to make sure you understand much with the following:
Good inspection results > extend interval
Accelerating corrosion > reduce interval
Stable CP + coatings > optimize interval
Process upset history > shorten interval