Laboratory Study on Non-Destructive Evaluation of Polyethylene Liquid Storage Tanks by Thermographic and Ultrasonic Methods

High-density polyethylene (HDPE) above-ground storage tanks (AST) are used by highway agencies to store liquid deicing chemicals for the purpose of road maintenance in winter. A sudden AST failure can cause significant economic and environmental impacts. While ASTs routinely inspected identify signs aging damage, current methods may not adequately capture all defects, particularly if they subsurface or too small be seen during visual inspection. Therefore, improve ability potential durability issues with HDPE ASTs, additional non-destructive evaluation (NDE) techniques need considered assessed applicability. Specifically, this study investigates efficiency using infrared thermography (IRT) as a rapid method simultaneously examine large areas tank exterior, which will followed closer inspections conventional phased array ultrasonic testing (UT) methods. Results show that IRT help detect defects shallow, specifically located within half tank’s wall thickness from surface. UT has at any depth. Moreover, helps stacked characterize each defect more precisely than IRT.