ThinkTank Case Study

by Joel L. Andreani, P.E. / November 2015

 

Hydrostatic Exemption Evaluation of API 650 Storage Tank

 

After storage tanks undergo repair, API, 653 Tank Inspection, Repair, Alteration, and Reconstruction, may require a hydrostatic test to provide assurance that the repairs are sound. This is required for “major repairs” (as defined in API 653) and for repairs at or near the bottom shell-to-floor joint due to the more complex nature of the stresses at this location. API 653, section 12.3 permits the use of an engineering evaluation and NDE in lieu of a hydrostatic test. The logic for the engineering evaluation approach is to show that flaws that could lead to failure (brittle fracture) are detectable using NDE rather than hydrostatic testing. If limiting flaw sizes are detectable by NDE and the weld in question is inspected 100% and found to be defect-free, hydrostatic testing is not required.

 

For more information about this case study, please complete the form below.

Learn More

Our Library is monitored and requests are only sent to business accounts.