AET & Tank Internal Inspection

[irish]

How helpful can performing AET be in delaying internal inspection of storage tanks as per API?
It has been recognized as a screening tool but what gain would it be having in the inspection confidence once performed.
Refer to API 653 along with API RBI.

[mechcolor]

See as you may know API 653 limits dependability on AET while considering that as an inspection tool providing quantitative inputs.
You may still use the technique to reconsider performing internal inspection at a later date as some confidence can be gained within RBI.
However, a lot depends upon how AET is applied. Usually, your RBI Engineer would question that before he factors that.

[arcpro]

See API RBI philosophy recognizes AET, it can support on-stream inspection credit and it may justify delayed internal inspection. But only within a broader RBI justification, not as a standalone exemption tool, and usually with reduced confidence weighting compared to direct inspection methods. Those direct methods are still recommended.
Check with your RBI engineer as he may ask you for validated AET vendor methodology, experienced Level III interpretation, historical correlation studies, previous intrusive inspection data, known corrosion mechanisms, acceptable soil-side corrosion control, no history of rapid deterioration before accepting any credit for AET and delaying the internal inspection.

[Dlew]

API RBI philosophy recognizes AET. It can support on-stream inspection credit as it may justify delayed internal inspection but only within a broader RBI justification, not as a standalone exemption tool, and usually with reduced confidence weighting compared to direct inspection methods.

[novice123]

As per my understanding, operators may run AET across dozens/hundreds of tanks, rank tanks by AE severity, extend low-risk tanks, open only high-risk candidates.
This is very common in refineries, terminals, petrochemical storage facilities, especially where shutdown cost is massive.